diff --git a/core/generator.ts b/core/generator.ts
index 790bb7e56..288ca9dae 100644
--- a/core/generator.ts
+++ b/core/generator.ts
@@ -17,6 +17,9 @@ import type {Block} from './block.js';
 import * as common from './common.js';
 import {Names, NameType} from './names.js';
 import type {Workspace} from './workspace.js';
+import {warn} from './utils/deprecation.js';
+
+export type BlockGenerator = (block: Block) => [string, number] | string | null;
 
 /**
  * Class for a code generator that translates the blocks into a language.
@@ -24,6 +27,9 @@ import type {Workspace} from './workspace.js';
 export class CodeGenerator {
   name_: string;
 
+  /** A dictionary of block generator functions keyed by block type. */
+  forBlock: {[type: string]: BlockGenerator} = Object.create(null);
+
   /**
    * This is used as a placeholder in functions defined using
    * CodeGenerator.provideFunction_.  It must not be legal code that could
@@ -220,15 +226,22 @@ export class CodeGenerator {
       return opt_thisOnly ? '' : this.blockToCode(block.getChildren(false)[0]);
     }
 
-    const func = (this as any)[block.type];
+    // Look up block generator function in dictionary - but fall back
+    // to looking up on this if not found, for backwards compatibility.
+    let func = this.forBlock[block.type];
+    if (!func && (this as any)[block.type]) {
+      warn(
+        'block generator functions on CodeGenerator objects',
+        '10.0',
+        '11.0',
+        'the .forBlock[blockType] dictionary'
+      );
+      func = (this as any)[block.type];
+    }
     if (typeof func !== 'function') {
       throw Error(
-        'Language "' +
-          this.name_ +
-          '" does not know how to generate ' +
-          'code for block type "' +
-          block.type +
-          '".'
+        `${this.name_} generator does not know how to generate code` +
+          `for block type "${block.type}".`
       );
     }
     // First argument to func.call is the value of 'this' in the generator.
diff --git a/generators/dart/colour.js b/generators/dart/colour.js
index b3bbc732a..b4d4ec7f7 100644
--- a/generators/dart/colour.js
+++ b/generators/dart/colour.js
@@ -16,13 +16,13 @@ import {dartGenerator as Dart} from '../dart.js';
 
 Dart.addReservedWords('Math');
 
-Dart['colour_picker'] = function(block) {
+Dart.forBlock['colour_picker'] = function(block) {
   // Colour picker.
   const code = Dart.quote_(block.getFieldValue('COLOUR'));
   return [code, Dart.ORDER_ATOMIC];
 };
 
-Dart['colour_random'] = function(block) {
+Dart.forBlock['colour_random'] = function(block) {
   // Generate a random colour.
   Dart.definitions_['import_dart_math'] = "import 'dart:math' as Math;";
   const functionName = Dart.provideFunction_('colour_random', `
@@ -38,7 +38,7 @@ String ${Dart.FUNCTION_NAME_PLACEHOLDER_}() {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['colour_rgb'] = function(block) {
+Dart.forBlock['colour_rgb'] = function(block) {
   // Compose a colour from RGB components expressed as percentages.
   const red = Dart.valueToCode(block, 'RED',
       Dart.ORDER_NONE) || 0;
@@ -69,7 +69,7 @@ String ${Dart.FUNCTION_NAME_PLACEHOLDER_}(num r, num g, num b) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['colour_blend'] = function(block) {
+Dart.forBlock['colour_blend'] = function(block) {
   // Blend two colours together.
   const c1 = Dart.valueToCode(block, 'COLOUR1', Dart.ORDER_NONE) || "'#000000'";
   const c2 = Dart.valueToCode(block, 'COLOUR2', Dart.ORDER_NONE) || "'#000000'";
diff --git a/generators/dart/lists.js b/generators/dart/lists.js
index 97b3c1f18..35e7ec431 100644
--- a/generators/dart/lists.js
+++ b/generators/dart/lists.js
@@ -17,12 +17,12 @@ import {dartGenerator as Dart} from '../dart.js';
 
 Dart.addReservedWords('Math');
 
-Dart['lists_create_empty'] = function(block) {
+Dart.forBlock['lists_create_empty'] = function(block) {
   // Create an empty list.
   return ['[]', Dart.ORDER_ATOMIC];
 };
 
-Dart['lists_create_with'] = function(block) {
+Dart.forBlock['lists_create_with'] = function(block) {
   // Create a list with any number of elements of any type.
   const elements = new Array(block.itemCount_);
   for (let i = 0; i < block.itemCount_; i++) {
@@ -32,7 +32,7 @@ Dart['lists_create_with'] = function(block) {
   return [code, Dart.ORDER_ATOMIC];
 };
 
-Dart['lists_repeat'] = function(block) {
+Dart.forBlock['lists_repeat'] = function(block) {
   // Create a list with one element repeated.
   const element = Dart.valueToCode(block, 'ITEM', Dart.ORDER_NONE) || 'null';
   const repeatCount = Dart.valueToCode(block, 'NUM', Dart.ORDER_NONE) || '0';
@@ -40,21 +40,21 @@ Dart['lists_repeat'] = function(block) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['lists_length'] = function(block) {
+Dart.forBlock['lists_length'] = function(block) {
   // String or array length.
   const list =
       Dart.valueToCode(block, 'VALUE', Dart.ORDER_UNARY_POSTFIX) || '[]';
   return [list + '.length', Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['lists_isEmpty'] = function(block) {
+Dart.forBlock['lists_isEmpty'] = function(block) {
   // Is the string null or array empty?
   const list =
       Dart.valueToCode(block, 'VALUE', Dart.ORDER_UNARY_POSTFIX) || '[]';
   return [list + '.isEmpty', Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['lists_indexOf'] = function(block) {
+Dart.forBlock['lists_indexOf'] = function(block) {
   // Find an item in the list.
   const operator =
       block.getFieldValue('END') === 'FIRST' ? 'indexOf' : 'lastIndexOf';
@@ -68,7 +68,7 @@ Dart['lists_indexOf'] = function(block) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['lists_getIndex'] = function(block) {
+Dart.forBlock['lists_getIndex'] = function(block) {
   // Get element at index.
   // Note: Until January 2013 this block did not have MODE or WHERE inputs.
   const mode = block.getFieldValue('MODE') || 'GET';
@@ -222,7 +222,7 @@ dynamic ${Dart.FUNCTION_NAME_PLACEHOLDER_}(List my_list) {
   throw Error('Unhandled combination (lists_getIndex).');
 };
 
-Dart['lists_setIndex'] = function(block) {
+Dart.forBlock['lists_setIndex'] = function(block) {
   // Set element at index.
   // Note: Until February 2013 this block did not have MODE or WHERE inputs.
   const mode = block.getFieldValue('MODE') || 'GET';
@@ -298,7 +298,7 @@ Dart['lists_setIndex'] = function(block) {
   throw Error('Unhandled combination (lists_setIndex).');
 };
 
-Dart['lists_getSublist'] = function(block) {
+Dart.forBlock['lists_getSublist'] = function(block) {
   // Get sublist.
   const list =
       Dart.valueToCode(block, 'LIST', Dart.ORDER_UNARY_POSTFIX) || '[]';
@@ -372,7 +372,7 @@ List ${Dart.FUNCTION_NAME_PLACEHOLDER_}(List list, String where1, num at1, Strin
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['lists_sort'] = function(block) {
+Dart.forBlock['lists_sort'] = function(block) {
   // Block for sorting a list.
   const list = Dart.valueToCode(block, 'LIST', Dart.ORDER_NONE) || '[]';
   const direction = block.getFieldValue('DIRECTION') === '1' ? 1 : -1;
@@ -399,7 +399,7 @@ List ${Dart.FUNCTION_NAME_PLACEHOLDER_}(List list, String type, int direction) {
   ];
 };
 
-Dart['lists_split'] = function(block) {
+Dart.forBlock['lists_split'] = function(block) {
   // Block for splitting text into a list, or joining a list into text.
   let input = Dart.valueToCode(block, 'INPUT', Dart.ORDER_UNARY_POSTFIX);
   const delimiter = Dart.valueToCode(block, 'DELIM', Dart.ORDER_NONE) || "''";
@@ -422,7 +422,7 @@ Dart['lists_split'] = function(block) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['lists_reverse'] = function(block) {
+Dart.forBlock['lists_reverse'] = function(block) {
   // Block for reversing a list.
   const list = Dart.valueToCode(block, 'LIST', Dart.ORDER_NONE) || '[]';
   // XXX What should the operator precedence be for a `new`?
diff --git a/generators/dart/logic.js b/generators/dart/logic.js
index 02c6ad7d6..743c54fe1 100644
--- a/generators/dart/logic.js
+++ b/generators/dart/logic.js
@@ -14,7 +14,7 @@ goog.declareModuleId('Blockly.Dart.logic');
 import {dartGenerator as Dart} from '../dart.js';
 
 
-Dart['controls_if'] = function(block) {
+Dart.forBlock['controls_if'] = function(block) {
   // If/elseif/else condition.
   let n = 0;
   let code = '', branchCode, conditionCode;
@@ -50,9 +50,9 @@ Dart['controls_if'] = function(block) {
   return code + '\n';
 };
 
-Dart['controls_ifelse'] = Dart['controls_if'];
+Dart.forBlock['controls_ifelse'] = Dart.forBlock['controls_if'];
 
-Dart['logic_compare'] = function(block) {
+Dart.forBlock['logic_compare'] = function(block) {
   // Comparison operator.
   const OPERATORS =
       {'EQ': '==', 'NEQ': '!=', 'LT': '<', 'LTE': '<=', 'GT': '>', 'GTE': '>='};
@@ -66,7 +66,7 @@ Dart['logic_compare'] = function(block) {
   return [code, order];
 };
 
-Dart['logic_operation'] = function(block) {
+Dart.forBlock['logic_operation'] = function(block) {
   // Operations 'and', 'or'.
   const operator = (block.getFieldValue('OP') === 'AND') ? '&&' : '||';
   const order =
@@ -91,7 +91,7 @@ Dart['logic_operation'] = function(block) {
   return [code, order];
 };
 
-Dart['logic_negate'] = function(block) {
+Dart.forBlock['logic_negate'] = function(block) {
   // Negation.
   const order = Dart.ORDER_UNARY_PREFIX;
   const argument0 = Dart.valueToCode(block, 'BOOL', order) || 'true';
@@ -99,18 +99,18 @@ Dart['logic_negate'] = function(block) {
   return [code, order];
 };
 
-Dart['logic_boolean'] = function(block) {
+Dart.forBlock['logic_boolean'] = function(block) {
   // Boolean values true and false.
   const code = (block.getFieldValue('BOOL') === 'TRUE') ? 'true' : 'false';
   return [code, Dart.ORDER_ATOMIC];
 };
 
-Dart['logic_null'] = function(block) {
+Dart.forBlock['logic_null'] = function(block) {
   // Null data type.
   return ['null', Dart.ORDER_ATOMIC];
 };
 
-Dart['logic_ternary'] = function(block) {
+Dart.forBlock['logic_ternary'] = function(block) {
   // Ternary operator.
   const value_if =
       Dart.valueToCode(block, 'IF', Dart.ORDER_CONDITIONAL) || 'false';
diff --git a/generators/dart/loops.js b/generators/dart/loops.js
index fec90cda2..3c507704e 100644
--- a/generators/dart/loops.js
+++ b/generators/dart/loops.js
@@ -16,7 +16,7 @@ import * as stringUtils from '../../core/utils/string.js';
 import {NameType} from '../../core/names.js';
 
 
-Dart['controls_repeat_ext'] = function(block) {
+Dart.forBlock['controls_repeat_ext'] = function(block) {
   let repeats;
   // Repeat n times.
   if (block.getField('TIMES')) {
@@ -40,9 +40,9 @@ Dart['controls_repeat_ext'] = function(block) {
   return code;
 };
 
-Dart['controls_repeat'] = Dart['controls_repeat_ext'];
+Dart.forBlock['controls_repeat'] = Dart.forBlock['controls_repeat_ext'];
 
-Dart['controls_whileUntil'] = function(block) {
+Dart.forBlock['controls_whileUntil'] = function(block) {
   // Do while/until loop.
   const until = block.getFieldValue('MODE') === 'UNTIL';
   let argument0 =
@@ -57,7 +57,7 @@ Dart['controls_whileUntil'] = function(block) {
   return 'while (' + argument0 + ') {\n' + branch + '}\n';
 };
 
-Dart['controls_for'] = function(block) {
+Dart.forBlock['controls_for'] = function(block) {
   // For loop.
   const variable0 =
       Dart.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -117,7 +117,7 @@ Dart['controls_for'] = function(block) {
   return code;
 };
 
-Dart['controls_forEach'] = function(block) {
+Dart.forBlock['controls_forEach'] = function(block) {
   // For each loop.
   const variable0 =
       Dart.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -130,7 +130,7 @@ Dart['controls_forEach'] = function(block) {
   return code;
 };
 
-Dart['controls_flow_statements'] = function(block) {
+Dart.forBlock['controls_flow_statements'] = function(block) {
   // Flow statements: continue, break.
   let xfix = '';
   if (Dart.STATEMENT_PREFIX) {
diff --git a/generators/dart/math.js b/generators/dart/math.js
index 76c9001c0..60c43a12a 100644
--- a/generators/dart/math.js
+++ b/generators/dart/math.js
@@ -17,7 +17,7 @@ import {dartGenerator as Dart} from '../dart.js';
 
 Dart.addReservedWords('Math');
 
-Dart['math_number'] = function(block) {
+Dart.forBlock['math_number'] = function(block) {
   // Numeric value.
   let code = Number(block.getFieldValue('NUM'));
   let order;
@@ -35,7 +35,7 @@ Dart['math_number'] = function(block) {
   return [code, order];
 };
 
-Dart['math_arithmetic'] = function(block) {
+Dart.forBlock['math_arithmetic'] = function(block) {
   // Basic arithmetic operators, and power.
   const OPERATORS = {
     'ADD': [' + ', Dart.ORDER_ADDITIVE],
@@ -60,7 +60,7 @@ Dart['math_arithmetic'] = function(block) {
   return [code, order];
 };
 
-Dart['math_single'] = function(block) {
+Dart.forBlock['math_single'] = function(block) {
   // Math operators with single operand.
   const operator = block.getFieldValue('OP');
   let code;
@@ -144,7 +144,7 @@ Dart['math_single'] = function(block) {
   return [code, Dart.ORDER_MULTIPLICATIVE];
 };
 
-Dart['math_constant'] = function(block) {
+Dart.forBlock['math_constant'] = function(block) {
   // Constants: PI, E, the Golden Ratio, sqrt(2), 1/sqrt(2), INFINITY.
   const CONSTANTS = {
     'PI': ['Math.pi', Dart.ORDER_UNARY_POSTFIX],
@@ -161,7 +161,7 @@ Dart['math_constant'] = function(block) {
   return CONSTANTS[constant];
 };
 
-Dart['math_number_property'] = function(block) {
+Dart.forBlock['math_number_property'] = function(block) {
   // Check if a number is even, odd, prime, whole, positive, or negative
   // or if it is divisible by certain number. Returns true or false.
   const PROPERTIES = {
@@ -216,7 +216,7 @@ bool ${Dart.FUNCTION_NAME_PLACEHOLDER_}(n) {
   return [code, outputOrder];
 };
 
-Dart['math_change'] = function(block) {
+Dart.forBlock['math_change'] = function(block) {
   // Add to a variable in place.
   const argument0 =
       Dart.valueToCode(block, 'DELTA', Dart.ORDER_ADDITIVE) || '0';
@@ -227,11 +227,11 @@ Dart['math_change'] = function(block) {
 };
 
 // Rounding functions have a single operand.
-Dart['math_round'] = Dart['math_single'];
+Dart.forBlock['math_round'] = Dart.forBlock['math_single'];
 // Trigonometry functions have a single operand.
-Dart['math_trig'] = Dart['math_single'];
+Dart.forBlock['math_trig'] = Dart.forBlock['math_single'];
 
-Dart['math_on_list'] = function(block) {
+Dart.forBlock['math_on_list'] = function(block) {
   // Math functions for lists.
   const func = block.getFieldValue('OP');
   const list = Dart.valueToCode(block, 'LIST', Dart.ORDER_NONE) || '[]';
@@ -386,7 +386,7 @@ dynamic ${Dart.FUNCTION_NAME_PLACEHOLDER_}(List myList) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['math_modulo'] = function(block) {
+Dart.forBlock['math_modulo'] = function(block) {
   // Remainder computation.
   const argument0 =
       Dart.valueToCode(block, 'DIVIDEND', Dart.ORDER_MULTIPLICATIVE) || '0';
@@ -396,7 +396,7 @@ Dart['math_modulo'] = function(block) {
   return [code, Dart.ORDER_MULTIPLICATIVE];
 };
 
-Dart['math_constrain'] = function(block) {
+Dart.forBlock['math_constrain'] = function(block) {
   // Constrain a number between two limits.
   Dart.definitions_['import_dart_math'] = 'import \'dart:math\' as Math;';
   const argument0 = Dart.valueToCode(block, 'VALUE', Dart.ORDER_NONE) || '0';
@@ -408,7 +408,7 @@ Dart['math_constrain'] = function(block) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['math_random_int'] = function(block) {
+Dart.forBlock['math_random_int'] = function(block) {
   // Random integer between [X] and [Y].
   Dart.definitions_['import_dart_math'] = 'import \'dart:math\' as Math;';
   const argument0 = Dart.valueToCode(block, 'FROM', Dart.ORDER_NONE) || '0';
@@ -428,13 +428,13 @@ int ${Dart.FUNCTION_NAME_PLACEHOLDER_}(num a, num b) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['math_random_float'] = function(block) {
+Dart.forBlock['math_random_float'] = function(block) {
   // Random fraction between 0 and 1.
   Dart.definitions_['import_dart_math'] = 'import \'dart:math\' as Math;';
   return ['new Math.Random().nextDouble()', Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['math_atan2'] = function(block) {
+Dart.forBlock['math_atan2'] = function(block) {
   // Arctangent of point (X, Y) in degrees from -180 to 180.
   Dart.definitions_['import_dart_math'] = 'import \'dart:math\' as Math;';
   const argument0 = Dart.valueToCode(block, 'X', Dart.ORDER_NONE) || '0';
diff --git a/generators/dart/procedures.js b/generators/dart/procedures.js
index c9d9f2958..bce63c687 100644
--- a/generators/dart/procedures.js
+++ b/generators/dart/procedures.js
@@ -15,7 +15,7 @@ import {NameType} from '../../core/names.js';
 import {dartGenerator as Dart} from '../dart.js';
 
 
-Dart['procedures_defreturn'] = function(block) {
+Dart.forBlock['procedures_defreturn'] = function(block) {
   // Define a procedure with a return value.
   const funcName =
       Dart.nameDB_.getName(block.getFieldValue('NAME'), NameType.PROCEDURE);
@@ -60,9 +60,9 @@ Dart['procedures_defreturn'] = function(block) {
 
 // Defining a procedure without a return value uses the same generator as
 // a procedure with a return value.
-Dart['procedures_defnoreturn'] = Dart['procedures_defreturn'];
+Dart.forBlock['procedures_defnoreturn'] = Dart.forBlock['procedures_defreturn'];
 
-Dart['procedures_callreturn'] = function(block) {
+Dart.forBlock['procedures_callreturn'] = function(block) {
   // Call a procedure with a return value.
   const funcName =
       Dart.nameDB_.getName(block.getFieldValue('NAME'), NameType.PROCEDURE);
@@ -75,15 +75,15 @@ Dart['procedures_callreturn'] = function(block) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['procedures_callnoreturn'] = function(block) {
+Dart.forBlock['procedures_callnoreturn'] = function(block) {
   // Call a procedure with no return value.
   // Generated code is for a function call as a statement is the same as a
   // function call as a value, with the addition of line ending.
-  const tuple = Dart['procedures_callreturn'](block);
+  const tuple = Dart.forBlock['procedures_callreturn'](block);
   return tuple[0] + ';\n';
 };
 
-Dart['procedures_ifreturn'] = function(block) {
+Dart.forBlock['procedures_ifreturn'] = function(block) {
   // Conditionally return value from a procedure.
   const condition =
       Dart.valueToCode(block, 'CONDITION', Dart.ORDER_NONE) || 'false';
diff --git a/generators/dart/text.js b/generators/dart/text.js
index 74966daf8..ad2463c0b 100644
--- a/generators/dart/text.js
+++ b/generators/dart/text.js
@@ -17,13 +17,13 @@ import {dartGenerator as Dart} from '../dart.js';
 
 Dart.addReservedWords('Html,Math');
 
-Dart['text'] = function(block) {
+Dart.forBlock['text'] = function(block) {
   // Text value.
   const code = Dart.quote_(block.getFieldValue('TEXT'));
   return [code, Dart.ORDER_ATOMIC];
 };
 
-Dart['text_multiline'] = function(block) {
+Dart.forBlock['text_multiline'] = function(block) {
   // Text value.
   const code = Dart.multiline_quote_(block.getFieldValue('TEXT'));
   const order =
@@ -31,7 +31,7 @@ Dart['text_multiline'] = function(block) {
   return [code, order];
 };
 
-Dart['text_join'] = function(block) {
+Dart.forBlock['text_join'] = function(block) {
   // Create a string made up of any number of elements of any type.
   switch (block.itemCount_) {
     case 0:
@@ -54,7 +54,7 @@ Dart['text_join'] = function(block) {
   }
 };
 
-Dart['text_append'] = function(block) {
+Dart.forBlock['text_append'] = function(block) {
   // Append to a variable in place.
   const varName =
       Dart.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -62,21 +62,21 @@ Dart['text_append'] = function(block) {
   return varName + ' = [' + varName + ', ' + value + '].join();\n';
 };
 
-Dart['text_length'] = function(block) {
+Dart.forBlock['text_length'] = function(block) {
   // String or array length.
   const text =
       Dart.valueToCode(block, 'VALUE', Dart.ORDER_UNARY_POSTFIX) || "''";
   return [text + '.length', Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['text_isEmpty'] = function(block) {
+Dart.forBlock['text_isEmpty'] = function(block) {
   // Is the string null or array empty?
   const text =
       Dart.valueToCode(block, 'VALUE', Dart.ORDER_UNARY_POSTFIX) || "''";
   return [text + '.isEmpty', Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['text_indexOf'] = function(block) {
+Dart.forBlock['text_indexOf'] = function(block) {
   // Search the text for a substring.
   const operator =
       block.getFieldValue('END') === 'FIRST' ? 'indexOf' : 'lastIndexOf';
@@ -90,7 +90,7 @@ Dart['text_indexOf'] = function(block) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['text_charAt'] = function(block) {
+Dart.forBlock['text_charAt'] = function(block) {
   // Get letter at index.
   // Note: Until January 2013 this block did not have the WHERE input.
   const where = block.getFieldValue('WHERE') || 'FROM_START';
@@ -137,7 +137,7 @@ String ${Dart.FUNCTION_NAME_PLACEHOLDER_}(String text) {
   throw Error('Unhandled option (text_charAt).');
 };
 
-Dart['text_getSubstring'] = function(block) {
+Dart.forBlock['text_getSubstring'] = function(block) {
   // Get substring.
   const where1 = block.getFieldValue('WHERE1');
   const where2 = block.getFieldValue('WHERE2');
@@ -215,7 +215,7 @@ String ${Dart.FUNCTION_NAME_PLACEHOLDER_}(String text, String where1, num at1, S
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['text_changeCase'] = function(block) {
+Dart.forBlock['text_changeCase'] = function(block) {
   // Change capitalization.
   const OPERATORS = {
     'UPPERCASE': '.toUpperCase()',
@@ -252,7 +252,7 @@ String ${Dart.FUNCTION_NAME_PLACEHOLDER_}(String str) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['text_trim'] = function(block) {
+Dart.forBlock['text_trim'] = function(block) {
   // Trim spaces.
   const OPERATORS = {
     'LEFT': '.replaceFirst(new RegExp(r\'^\\s+\'), \'\')',
@@ -265,13 +265,13 @@ Dart['text_trim'] = function(block) {
   return [text + operator, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['text_print'] = function(block) {
+Dart.forBlock['text_print'] = function(block) {
   // Print statement.
   const msg = Dart.valueToCode(block, 'TEXT', Dart.ORDER_NONE) || "''";
   return 'print(' + msg + ');\n';
 };
 
-Dart['text_prompt_ext'] = function(block) {
+Dart.forBlock['text_prompt_ext'] = function(block) {
   // Prompt function.
   Dart.definitions_['import_dart_html'] = 'import \'dart:html\' as Html;';
   let msg;
@@ -291,9 +291,9 @@ Dart['text_prompt_ext'] = function(block) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['text_prompt'] = Dart['text_prompt_ext'];
+Dart.forBlock['text_prompt'] = Dart.forBlock['text_prompt_ext'];
 
-Dart['text_count'] = function(block) {
+Dart.forBlock['text_count'] = function(block) {
   const text = Dart.valueToCode(block, 'TEXT', Dart.ORDER_NONE) || "''";
   const sub = Dart.valueToCode(block, 'SUB', Dart.ORDER_NONE) || "''";
   // Substring count is not a native Dart function.  Define one.
@@ -318,7 +318,7 @@ int ${Dart.FUNCTION_NAME_PLACEHOLDER_}(String haystack, String needle) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['text_replace'] = function(block) {
+Dart.forBlock['text_replace'] = function(block) {
   const text =
       Dart.valueToCode(block, 'TEXT', Dart.ORDER_UNARY_POSTFIX) || "''";
   const from = Dart.valueToCode(block, 'FROM', Dart.ORDER_NONE) || "''";
@@ -327,7 +327,7 @@ Dart['text_replace'] = function(block) {
   return [code, Dart.ORDER_UNARY_POSTFIX];
 };
 
-Dart['text_reverse'] = function(block) {
+Dart.forBlock['text_reverse'] = function(block) {
   // There isn't a sensible way to do this in Dart. See:
   // http://stackoverflow.com/a/21613700/3529104
   // Implementing something is possibly better than not implementing anything?
diff --git a/generators/dart/variables.js b/generators/dart/variables.js
index 462ba0d4f..d6d62584c 100644
--- a/generators/dart/variables.js
+++ b/generators/dart/variables.js
@@ -15,14 +15,14 @@ import {NameType} from '../../core/names.js';
 import {dartGenerator as Dart} from '../dart.js';
 
 
-Dart['variables_get'] = function(block) {
+Dart.forBlock['variables_get'] = function(block) {
   // Variable getter.
   const code =
       Dart.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
   return [code, Dart.ORDER_ATOMIC];
 };
 
-Dart['variables_set'] = function(block) {
+Dart.forBlock['variables_set'] = function(block) {
   // Variable setter.
   const argument0 =
       Dart.valueToCode(block, 'VALUE', Dart.ORDER_ASSIGNMENT) || '0';
diff --git a/generators/dart/variables_dynamic.js b/generators/dart/variables_dynamic.js
index 9fe63c476..d3ada9aa6 100644
--- a/generators/dart/variables_dynamic.js
+++ b/generators/dart/variables_dynamic.js
@@ -16,5 +16,5 @@ import './variables.js';
 
 
 // Dart is dynamically typed.
-Dart['variables_get_dynamic'] = Dart['variables_get'];
-Dart['variables_set_dynamic'] = Dart['variables_set'];
+Dart.forBlock['variables_get_dynamic'] = Dart.forBlock['variables_get'];
+Dart.forBlock['variables_set_dynamic'] = Dart.forBlock['variables_set'];
diff --git a/generators/javascript/colour.js b/generators/javascript/colour.js
index e4c0c5598..dce2d22f4 100644
--- a/generators/javascript/colour.js
+++ b/generators/javascript/colour.js
@@ -14,13 +14,13 @@ goog.declareModuleId('Blockly.JavaScript.colour');
 import {javascriptGenerator as JavaScript} from '../javascript.js';
 
 
-JavaScript['colour_picker'] = function(block) {
+JavaScript.forBlock['colour_picker'] = function(block) {
   // Colour picker.
   const code = JavaScript.quote_(block.getFieldValue('COLOUR'));
   return [code, JavaScript.ORDER_ATOMIC];
 };
 
-JavaScript['colour_random'] = function(block) {
+JavaScript.forBlock['colour_random'] = function(block) {
   // Generate a random colour.
   const functionName = JavaScript.provideFunction_('colourRandom', `
 function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}() {
@@ -32,7 +32,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}() {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['colour_rgb'] = function(block) {
+JavaScript.forBlock['colour_rgb'] = function(block) {
   // Compose a colour from RGB components expressed as percentages.
   const red = JavaScript.valueToCode(block, 'RED', JavaScript.ORDER_NONE) || 0;
   const green =
@@ -54,7 +54,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(r, g, b) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['colour_blend'] = function(block) {
+JavaScript.forBlock['colour_blend'] = function(block) {
   // Blend two colours together.
   const c1 = JavaScript.valueToCode(block, 'COLOUR1', JavaScript.ORDER_NONE) ||
       "'#000000'";
diff --git a/generators/javascript/lists.js b/generators/javascript/lists.js
index 2dbdb62b8..317588e55 100644
--- a/generators/javascript/lists.js
+++ b/generators/javascript/lists.js
@@ -16,12 +16,12 @@ import {NameType} from '../../core/names.js';
 import {javascriptGenerator as JavaScript} from '../javascript.js';
 
 
-JavaScript['lists_create_empty'] = function(block) {
+JavaScript.forBlock['lists_create_empty'] = function(block) {
   // Create an empty list.
   return ['[]', JavaScript.ORDER_ATOMIC];
 };
 
-JavaScript['lists_create_with'] = function(block) {
+JavaScript.forBlock['lists_create_with'] = function(block) {
   // Create a list with any number of elements of any type.
   const elements = new Array(block.itemCount_);
   for (let i = 0; i < block.itemCount_; i++) {
@@ -33,7 +33,7 @@ JavaScript['lists_create_with'] = function(block) {
   return [code, JavaScript.ORDER_ATOMIC];
 };
 
-JavaScript['lists_repeat'] = function(block) {
+JavaScript.forBlock['lists_repeat'] = function(block) {
   // Create a list with one element repeated.
   const functionName = JavaScript.provideFunction_('listsRepeat', `
 function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(value, n) {
@@ -52,21 +52,21 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(value, n) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['lists_length'] = function(block) {
+JavaScript.forBlock['lists_length'] = function(block) {
   // String or array length.
   const list =
       JavaScript.valueToCode(block, 'VALUE', JavaScript.ORDER_MEMBER) || '[]';
   return [list + '.length', JavaScript.ORDER_MEMBER];
 };
 
-JavaScript['lists_isEmpty'] = function(block) {
+JavaScript.forBlock['lists_isEmpty'] = function(block) {
   // Is the string null or array empty?
   const list =
       JavaScript.valueToCode(block, 'VALUE', JavaScript.ORDER_MEMBER) || '[]';
   return ['!' + list + '.length', JavaScript.ORDER_LOGICAL_NOT];
 };
 
-JavaScript['lists_indexOf'] = function(block) {
+JavaScript.forBlock['lists_indexOf'] = function(block) {
   // Find an item in the list.
   const operator =
       block.getFieldValue('END') === 'FIRST' ? 'indexOf' : 'lastIndexOf';
@@ -81,7 +81,7 @@ JavaScript['lists_indexOf'] = function(block) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['lists_getIndex'] = function(block) {
+JavaScript.forBlock['lists_getIndex'] = function(block) {
   // Get element at index.
   // Note: Until January 2013 this block did not have MODE or WHERE inputs.
   const mode = block.getFieldValue('MODE') || 'GET';
@@ -162,7 +162,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(list, remove) {
   throw Error('Unhandled combination (lists_getIndex).');
 };
 
-JavaScript['lists_setIndex'] = function(block) {
+JavaScript.forBlock['lists_setIndex'] = function(block) {
   // Set element at index.
   // Note: Until February 2013 this block did not have MODE or WHERE inputs.
   let list =
@@ -262,7 +262,7 @@ const getSubstringIndex = function(listName, where, opt_at) {
   }
 };
 
-JavaScript['lists_getSublist'] = function(block) {
+JavaScript.forBlock['lists_getSublist'] = function(block) {
   // Get sublist.
   const list =
       JavaScript.valueToCode(block, 'LIST', JavaScript.ORDER_MEMBER) || '[]';
@@ -342,7 +342,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(sequence${at1Param}${at2Param}
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['lists_sort'] = function(block) {
+JavaScript.forBlock['lists_sort'] = function(block) {
   // Block for sorting a list.
   const list =
       JavaScript.valueToCode(block, 'LIST', JavaScript.ORDER_FUNCTION_CALL) ||
@@ -371,7 +371,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(type, direction) {
   ];
 };
 
-JavaScript['lists_split'] = function(block) {
+JavaScript.forBlock['lists_split'] = function(block) {
   // Block for splitting text into a list, or joining a list into text.
   let input = JavaScript.valueToCode(block, 'INPUT', JavaScript.ORDER_MEMBER);
   const delimiter =
@@ -395,7 +395,7 @@ JavaScript['lists_split'] = function(block) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['lists_reverse'] = function(block) {
+JavaScript.forBlock['lists_reverse'] = function(block) {
   // Block for reversing a list.
   const list =
       JavaScript.valueToCode(block, 'LIST', JavaScript.ORDER_FUNCTION_CALL) ||
diff --git a/generators/javascript/logic.js b/generators/javascript/logic.js
index fa944dee2..93420fabf 100644
--- a/generators/javascript/logic.js
+++ b/generators/javascript/logic.js
@@ -14,7 +14,7 @@ goog.declareModuleId('Blockly.JavaScript.logic');
 import {javascriptGenerator as JavaScript} from '../javascript.js';
 
 
-JavaScript['controls_if'] = function(block) {
+JavaScript.forBlock['controls_if'] = function(block) {
   // If/elseif/else condition.
   let n = 0;
   let code = '';
@@ -51,9 +51,9 @@ JavaScript['controls_if'] = function(block) {
   return code + '\n';
 };
 
-JavaScript['controls_ifelse'] = JavaScript['controls_if'];
+JavaScript.forBlock['controls_ifelse'] = JavaScript.forBlock['controls_if'];
 
-JavaScript['logic_compare'] = function(block) {
+JavaScript.forBlock['logic_compare'] = function(block) {
   // Comparison operator.
   const OPERATORS =
       {'EQ': '==', 'NEQ': '!=', 'LT': '<', 'LTE': '<=', 'GT': '>', 'GTE': '>='};
@@ -67,7 +67,7 @@ JavaScript['logic_compare'] = function(block) {
   return [code, order];
 };
 
-JavaScript['logic_operation'] = function(block) {
+JavaScript.forBlock['logic_operation'] = function(block) {
   // Operations 'and', 'or'.
   const operator = (block.getFieldValue('OP') === 'AND') ? '&&' : '||';
   const order = (operator === '&&') ? JavaScript.ORDER_LOGICAL_AND :
@@ -92,7 +92,7 @@ JavaScript['logic_operation'] = function(block) {
   return [code, order];
 };
 
-JavaScript['logic_negate'] = function(block) {
+JavaScript.forBlock['logic_negate'] = function(block) {
   // Negation.
   const order = JavaScript.ORDER_LOGICAL_NOT;
   const argument0 = JavaScript.valueToCode(block, 'BOOL', order) || 'true';
@@ -100,18 +100,18 @@ JavaScript['logic_negate'] = function(block) {
   return [code, order];
 };
 
-JavaScript['logic_boolean'] = function(block) {
+JavaScript.forBlock['logic_boolean'] = function(block) {
   // Boolean values true and false.
   const code = (block.getFieldValue('BOOL') === 'TRUE') ? 'true' : 'false';
   return [code, JavaScript.ORDER_ATOMIC];
 };
 
-JavaScript['logic_null'] = function(block) {
+JavaScript.forBlock['logic_null'] = function(block) {
   // Null data type.
   return ['null', JavaScript.ORDER_ATOMIC];
 };
 
-JavaScript['logic_ternary'] = function(block) {
+JavaScript.forBlock['logic_ternary'] = function(block) {
   // Ternary operator.
   const value_if =
       JavaScript.valueToCode(block, 'IF', JavaScript.ORDER_CONDITIONAL) ||
diff --git a/generators/javascript/loops.js b/generators/javascript/loops.js
index 76ef6ec7e..7e2a90cf0 100644
--- a/generators/javascript/loops.js
+++ b/generators/javascript/loops.js
@@ -16,7 +16,7 @@ import {NameType} from '../../core/names.js';
 import {javascriptGenerator as JavaScript} from '../javascript.js';
 
 
-JavaScript['controls_repeat_ext'] = function(block) {
+JavaScript.forBlock['controls_repeat_ext'] = function(block) {
   // Repeat n times.
   let repeats;
   if (block.getField('TIMES')) {
@@ -44,9 +44,9 @@ JavaScript['controls_repeat_ext'] = function(block) {
   return code;
 };
 
-JavaScript['controls_repeat'] = JavaScript['controls_repeat_ext'];
+JavaScript.forBlock['controls_repeat'] = JavaScript.forBlock['controls_repeat_ext'];
 
-JavaScript['controls_whileUntil'] = function(block) {
+JavaScript.forBlock['controls_whileUntil'] = function(block) {
   // Do while/until loop.
   const until = block.getFieldValue('MODE') === 'UNTIL';
   let argument0 =
@@ -62,7 +62,7 @@ JavaScript['controls_whileUntil'] = function(block) {
   return 'while (' + argument0 + ') {\n' + branch + '}\n';
 };
 
-JavaScript['controls_for'] = function(block) {
+JavaScript.forBlock['controls_for'] = function(block) {
   // For loop.
   const variable0 =
       JavaScript.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -124,7 +124,7 @@ JavaScript['controls_for'] = function(block) {
   return code;
 };
 
-JavaScript['controls_forEach'] = function(block) {
+JavaScript.forBlock['controls_forEach'] = function(block) {
   // For each loop.
   const variable0 =
       JavaScript.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -149,7 +149,7 @@ JavaScript['controls_forEach'] = function(block) {
   return code;
 };
 
-JavaScript['controls_flow_statements'] = function(block) {
+JavaScript.forBlock['controls_flow_statements'] = function(block) {
   // Flow statements: continue, break.
   let xfix = '';
   if (JavaScript.STATEMENT_PREFIX) {
diff --git a/generators/javascript/math.js b/generators/javascript/math.js
index 0007bf14c..5d62aae2b 100644
--- a/generators/javascript/math.js
+++ b/generators/javascript/math.js
@@ -16,7 +16,7 @@ import {NameType} from '../../core/names.js';
 import {javascriptGenerator as JavaScript} from '../javascript.js';
 
 
-JavaScript['math_number'] = function(block) {
+JavaScript.forBlock['math_number'] = function(block) {
   // Numeric value.
   const code = Number(block.getFieldValue('NUM'));
   const order = code >= 0 ? JavaScript.ORDER_ATOMIC :
@@ -24,7 +24,7 @@ JavaScript['math_number'] = function(block) {
   return [code, order];
 };
 
-JavaScript['math_arithmetic'] = function(block) {
+JavaScript.forBlock['math_arithmetic'] = function(block) {
   // Basic arithmetic operators, and power.
   const OPERATORS = {
     'ADD': [' + ', JavaScript.ORDER_ADDITION],
@@ -48,7 +48,7 @@ JavaScript['math_arithmetic'] = function(block) {
   return [code, order];
 };
 
-JavaScript['math_single'] = function(block) {
+JavaScript.forBlock['math_single'] = function(block) {
   // Math operators with single operand.
   const operator = block.getFieldValue('OP');
   let code;
@@ -132,7 +132,7 @@ JavaScript['math_single'] = function(block) {
   return [code, JavaScript.ORDER_DIVISION];
 };
 
-JavaScript['math_constant'] = function(block) {
+JavaScript.forBlock['math_constant'] = function(block) {
   // Constants: PI, E, the Golden Ratio, sqrt(2), 1/sqrt(2), INFINITY.
   const CONSTANTS = {
     'PI': ['Math.PI', JavaScript.ORDER_MEMBER],
@@ -145,7 +145,7 @@ JavaScript['math_constant'] = function(block) {
   return CONSTANTS[block.getFieldValue('CONSTANT')];
 };
 
-JavaScript['math_number_property'] = function(block) {
+JavaScript.forBlock['math_number_property'] = function(block) {
   // Check if a number is even, odd, prime, whole, positive, or negative
   // or if it is divisible by certain number. Returns true or false.
   const PROPERTIES = {
@@ -198,7 +198,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(n) {
   return [code, outputOrder];
 };
 
-JavaScript['math_change'] = function(block) {
+JavaScript.forBlock['math_change'] = function(block) {
   // Add to a variable in place.
   const argument0 = JavaScript.valueToCode(block, 'DELTA',
       JavaScript.ORDER_ADDITION) || '0';
@@ -209,11 +209,11 @@ JavaScript['math_change'] = function(block) {
 };
 
 // Rounding functions have a single operand.
-JavaScript['math_round'] = JavaScript['math_single'];
+JavaScript.forBlock['math_round'] = JavaScript.forBlock['math_single'];
 // Trigonometry functions have a single operand.
-JavaScript['math_trig'] = JavaScript['math_single'];
+JavaScript.forBlock['math_trig'] = JavaScript.forBlock['math_single'];
 
-JavaScript['math_on_list'] = function(block) {
+JavaScript.forBlock['math_on_list'] = function(block) {
   // Math functions for lists.
   const func = block.getFieldValue('OP');
   let list;
@@ -341,7 +341,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(list) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['math_modulo'] = function(block) {
+JavaScript.forBlock['math_modulo'] = function(block) {
   // Remainder computation.
   const argument0 = JavaScript.valueToCode(block, 'DIVIDEND',
       JavaScript.ORDER_MODULUS) || '0';
@@ -351,7 +351,7 @@ JavaScript['math_modulo'] = function(block) {
   return [code, JavaScript.ORDER_MODULUS];
 };
 
-JavaScript['math_constrain'] = function(block) {
+JavaScript.forBlock['math_constrain'] = function(block) {
   // Constrain a number between two limits.
   const argument0 = JavaScript.valueToCode(block, 'VALUE',
       JavaScript.ORDER_NONE) || '0';
@@ -364,7 +364,7 @@ JavaScript['math_constrain'] = function(block) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['math_random_int'] = function(block) {
+JavaScript.forBlock['math_random_int'] = function(block) {
   // Random integer between [X] and [Y].
   const argument0 = JavaScript.valueToCode(block, 'FROM',
       JavaScript.ORDER_NONE) || '0';
@@ -385,12 +385,12 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(a, b) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['math_random_float'] = function(block) {
+JavaScript.forBlock['math_random_float'] = function(block) {
   // Random fraction between 0 and 1.
   return ['Math.random()', JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['math_atan2'] = function(block) {
+JavaScript.forBlock['math_atan2'] = function(block) {
   // Arctangent of point (X, Y) in degrees from -180 to 180.
   const argument0 = JavaScript.valueToCode(block, 'X',
       JavaScript.ORDER_NONE) || '0';
diff --git a/generators/javascript/procedures.js b/generators/javascript/procedures.js
index 2e9fa91a0..dbb59bc18 100644
--- a/generators/javascript/procedures.js
+++ b/generators/javascript/procedures.js
@@ -15,7 +15,7 @@ import {NameType} from '../../core/names.js';
 import {javascriptGenerator as JavaScript} from '../javascript.js';
 
 
-JavaScript['procedures_defreturn'] = function(block) {
+JavaScript.forBlock['procedures_defreturn'] = function(block) {
   // Define a procedure with a return value.
   const funcName = JavaScript.nameDB_.getName(
       block.getFieldValue('NAME'), NameType.PROCEDURE);
@@ -61,9 +61,9 @@ JavaScript['procedures_defreturn'] = function(block) {
 
 // Defining a procedure without a return value uses the same generator as
 // a procedure with a return value.
-JavaScript['procedures_defnoreturn'] = JavaScript['procedures_defreturn'];
+JavaScript.forBlock['procedures_defnoreturn'] = JavaScript.forBlock['procedures_defreturn'];
 
-JavaScript['procedures_callreturn'] = function(block) {
+JavaScript.forBlock['procedures_callreturn'] = function(block) {
   // Call a procedure with a return value.
   const funcName = JavaScript.nameDB_.getName(
       block.getFieldValue('NAME'), NameType.PROCEDURE);
@@ -77,15 +77,15 @@ JavaScript['procedures_callreturn'] = function(block) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['procedures_callnoreturn'] = function(block) {
+JavaScript.forBlock['procedures_callnoreturn'] = function(block) {
   // Call a procedure with no return value.
   // Generated code is for a function call as a statement is the same as a
   // function call as a value, with the addition of line ending.
-  const tuple = JavaScript['procedures_callreturn'](block);
+  const tuple = JavaScript.forBlock['procedures_callreturn'](block);
   return tuple[0] + ';\n';
 };
 
-JavaScript['procedures_ifreturn'] = function(block) {
+JavaScript.forBlock['procedures_ifreturn'] = function(block) {
   // Conditionally return value from a procedure.
   const condition =
       JavaScript.valueToCode(block, 'CONDITION', JavaScript.ORDER_NONE) ||
diff --git a/generators/javascript/text.js b/generators/javascript/text.js
index 9e2cb43e1..149f823ee 100644
--- a/generators/javascript/text.js
+++ b/generators/javascript/text.js
@@ -53,13 +53,13 @@ const getSubstringIndex = function(stringName, where, opt_at) {
   }
 };
 
-JavaScript['text'] = function(block) {
+JavaScript.forBlock['text'] = function(block) {
   // Text value.
   const code = JavaScript.quote_(block.getFieldValue('TEXT'));
   return [code, JavaScript.ORDER_ATOMIC];
 };
 
-JavaScript['text_multiline'] = function(block) {
+JavaScript.forBlock['text_multiline'] = function(block) {
   // Text value.
   const code = JavaScript.multiline_quote_(block.getFieldValue('TEXT'));
   const order = code.indexOf('+') !== -1 ? JavaScript.ORDER_ADDITION :
@@ -67,7 +67,7 @@ JavaScript['text_multiline'] = function(block) {
   return [code, order];
 };
 
-JavaScript['text_join'] = function(block) {
+JavaScript.forBlock['text_join'] = function(block) {
   // Create a string made up of any number of elements of any type.
   switch (block.itemCount_) {
     case 0:
@@ -99,7 +99,7 @@ JavaScript['text_join'] = function(block) {
   }
 };
 
-JavaScript['text_append'] = function(block) {
+JavaScript.forBlock['text_append'] = function(block) {
   // Append to a variable in place.
   const varName = JavaScript.nameDB_.getName(
       block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -110,21 +110,21 @@ JavaScript['text_append'] = function(block) {
   return code;
 };
 
-JavaScript['text_length'] = function(block) {
+JavaScript.forBlock['text_length'] = function(block) {
   // String or array length.
   const text = JavaScript.valueToCode(block, 'VALUE',
       JavaScript.ORDER_MEMBER) || "''";
   return [text + '.length', JavaScript.ORDER_MEMBER];
 };
 
-JavaScript['text_isEmpty'] = function(block) {
+JavaScript.forBlock['text_isEmpty'] = function(block) {
   // Is the string null or array empty?
   const text = JavaScript.valueToCode(block, 'VALUE',
       JavaScript.ORDER_MEMBER) || "''";
   return ['!' + text + '.length', JavaScript.ORDER_LOGICAL_NOT];
 };
 
-JavaScript['text_indexOf'] = function(block) {
+JavaScript.forBlock['text_indexOf'] = function(block) {
   // Search the text for a substring.
   const operator = block.getFieldValue('END') === 'FIRST' ?
       'indexOf' : 'lastIndexOf';
@@ -140,7 +140,7 @@ JavaScript['text_indexOf'] = function(block) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['text_charAt'] = function(block) {
+JavaScript.forBlock['text_charAt'] = function(block) {
   // Get letter at index.
   // Note: Until January 2013 this block did not have the WHERE input.
   const where = block.getFieldValue('WHERE') || 'FROM_START';
@@ -181,7 +181,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(text) {
   throw Error('Unhandled option (text_charAt).');
 };
 
-JavaScript['text_getSubstring'] = function(block) {
+JavaScript.forBlock['text_getSubstring'] = function(block) {
   // Get substring.
   const where1 = block.getFieldValue('WHERE1');
   const where2 = block.getFieldValue('WHERE2');
@@ -259,7 +259,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(sequence${at1Param}${at2Param}
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['text_changeCase'] = function(block) {
+JavaScript.forBlock['text_changeCase'] = function(block) {
   // Change capitalization.
   const OPERATORS = {
     'UPPERCASE': '.toUpperCase()',
@@ -286,7 +286,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(str) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['text_trim'] = function(block) {
+JavaScript.forBlock['text_trim'] = function(block) {
   // Trim spaces.
   const OPERATORS = {
     'LEFT': ".replace(/^[\\s\\xa0]+/, '')",
@@ -299,14 +299,14 @@ JavaScript['text_trim'] = function(block) {
   return [text + operator, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['text_print'] = function(block) {
+JavaScript.forBlock['text_print'] = function(block) {
   // Print statement.
   const msg = JavaScript.valueToCode(block, 'TEXT',
       JavaScript.ORDER_NONE) || "''";
   return 'window.alert(' + msg + ');\n';
 };
 
-JavaScript['text_prompt_ext'] = function(block) {
+JavaScript.forBlock['text_prompt_ext'] = function(block) {
   // Prompt function.
   let msg;
   if (block.getField('TEXT')) {
@@ -324,9 +324,9 @@ JavaScript['text_prompt_ext'] = function(block) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['text_prompt'] = JavaScript['text_prompt_ext'];
+JavaScript.forBlock['text_prompt'] = JavaScript.forBlock['text_prompt_ext'];
 
-JavaScript['text_count'] = function(block) {
+JavaScript.forBlock['text_count'] = function(block) {
   const text = JavaScript.valueToCode(block, 'TEXT',
       JavaScript.ORDER_NONE) || "''";
   const sub = JavaScript.valueToCode(block, 'SUB',
@@ -344,7 +344,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(haystack, needle) {
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['text_replace'] = function(block) {
+JavaScript.forBlock['text_replace'] = function(block) {
   const text = JavaScript.valueToCode(block, 'TEXT',
       JavaScript.ORDER_NONE) || "''";
   const from = JavaScript.valueToCode(block, 'FROM',
@@ -363,7 +363,7 @@ function ${JavaScript.FUNCTION_NAME_PLACEHOLDER_}(haystack, needle, replacement)
   return [code, JavaScript.ORDER_FUNCTION_CALL];
 };
 
-JavaScript['text_reverse'] = function(block) {
+JavaScript.forBlock['text_reverse'] = function(block) {
   const text = JavaScript.valueToCode(block, 'TEXT',
       JavaScript.ORDER_MEMBER) || "''";
   const code = text + ".split('').reverse().join('')";
diff --git a/generators/javascript/variables.js b/generators/javascript/variables.js
index 14e9b004b..df84144a4 100644
--- a/generators/javascript/variables.js
+++ b/generators/javascript/variables.js
@@ -15,14 +15,14 @@ import {NameType} from '../../core/names.js';
 import {javascriptGenerator as JavaScript} from '../javascript.js';
 
 
-JavaScript['variables_get'] = function(block) {
+JavaScript.forBlock['variables_get'] = function(block) {
   // Variable getter.
   const code = JavaScript.nameDB_.getName(block.getFieldValue('VAR'),
       NameType.VARIABLE);
   return [code, JavaScript.ORDER_ATOMIC];
 };
 
-JavaScript['variables_set'] = function(block) {
+JavaScript.forBlock['variables_set'] = function(block) {
   // Variable setter.
   const argument0 = JavaScript.valueToCode(
                         block, 'VALUE', JavaScript.ORDER_ASSIGNMENT) || '0';
diff --git a/generators/javascript/variables_dynamic.js b/generators/javascript/variables_dynamic.js
index 07c29cd26..0371d2f86 100644
--- a/generators/javascript/variables_dynamic.js
+++ b/generators/javascript/variables_dynamic.js
@@ -16,5 +16,5 @@ import './variables.js';
 
 
 // JavaScript is dynamically typed.
-JavaScript['variables_get_dynamic'] = JavaScript['variables_get'];
-JavaScript['variables_set_dynamic'] = JavaScript['variables_set'];
+JavaScript.forBlock['variables_get_dynamic'] = JavaScript.forBlock['variables_get'];
+JavaScript.forBlock['variables_set_dynamic'] = JavaScript.forBlock['variables_set'];
diff --git a/generators/lua/colour.js b/generators/lua/colour.js
index 52ad3bd98..d248b0f94 100644
--- a/generators/lua/colour.js
+++ b/generators/lua/colour.js
@@ -14,19 +14,19 @@ goog.declareModuleId('Blockly.Lua.colour');
 import {luaGenerator as Lua} from '../lua.js';
 
 
-Lua['colour_picker'] = function(block) {
+Lua.forBlock['colour_picker'] = function(block) {
   // Colour picker.
   const code = Lua.quote_(block.getFieldValue('COLOUR'));
   return [code, Lua.ORDER_ATOMIC];
 };
 
-Lua['colour_random'] = function(block) {
+Lua.forBlock['colour_random'] = function(block) {
   // Generate a random colour.
   const code = 'string.format("#%06x", math.random(0, 2^24 - 1))';
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['colour_rgb'] = function(block) {
+Lua.forBlock['colour_rgb'] = function(block) {
   // Compose a colour from RGB components expressed as percentages.
   const functionName = Lua.provideFunction_('colour_rgb', `
 function ${Lua.FUNCTION_NAME_PLACEHOLDER_}(r, g, b)
@@ -43,7 +43,7 @@ end
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['colour_blend'] = function(block) {
+Lua.forBlock['colour_blend'] = function(block) {
   // Blend two colours together.
   const functionName = Lua.provideFunction_('colour_blend', `
 function ${Lua.FUNCTION_NAME_PLACEHOLDER_}(colour1, colour2, ratio)
diff --git a/generators/lua/lists.js b/generators/lua/lists.js
index dd6e66ef5..aeed7863e 100644
--- a/generators/lua/lists.js
+++ b/generators/lua/lists.js
@@ -15,12 +15,12 @@ import {NameType} from '../../core/names.js';
 import {luaGenerator as Lua} from '../lua.js';
 
 
-Lua['lists_create_empty'] = function(block) {
+Lua.forBlock['lists_create_empty'] = function(block) {
   // Create an empty list.
   return ['{}', Lua.ORDER_HIGH];
 };
 
-Lua['lists_create_with'] = function(block) {
+Lua.forBlock['lists_create_with'] = function(block) {
   // Create a list with any number of elements of any type.
   const elements = new Array(block.itemCount_);
   for (let i = 0; i < block.itemCount_; i++) {
@@ -30,7 +30,7 @@ Lua['lists_create_with'] = function(block) {
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['lists_repeat'] = function(block) {
+Lua.forBlock['lists_repeat'] = function(block) {
   // Create a list with one element repeated.
   const functionName = Lua.provideFunction_('create_list_repeated', `
 function ${Lua.FUNCTION_NAME_PLACEHOLDER_}(item, count)
@@ -47,20 +47,20 @@ end
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['lists_length'] = function(block) {
+Lua.forBlock['lists_length'] = function(block) {
   // String or array length.
   const list = Lua.valueToCode(block, 'VALUE', Lua.ORDER_UNARY) || '{}';
   return ['#' + list, Lua.ORDER_UNARY];
 };
 
-Lua['lists_isEmpty'] = function(block) {
+Lua.forBlock['lists_isEmpty'] = function(block) {
   // Is the string null or array empty?
   const list = Lua.valueToCode(block, 'VALUE', Lua.ORDER_UNARY) || '{}';
   const code = '#' + list + ' == 0';
   return [code, Lua.ORDER_RELATIONAL];
 };
 
-Lua['lists_indexOf'] = function(block) {
+Lua.forBlock['lists_indexOf'] = function(block) {
   // Find an item in the list.
   const item = Lua.valueToCode(block, 'FIND', Lua.ORDER_NONE) || "''";
   const list = Lua.valueToCode(block, 'VALUE', Lua.ORDER_NONE) || '{}';
@@ -113,7 +113,7 @@ const getListIndex = function(listName, where, opt_at) {
   }
 };
 
-Lua['lists_getIndex'] = function(block) {
+Lua.forBlock['lists_getIndex'] = function(block) {
   // Get element at index.
   // Note: Until January 2013 this block did not have MODE or WHERE inputs.
   const mode = block.getFieldValue('MODE') || 'GET';
@@ -191,7 +191,7 @@ Lua['lists_getIndex'] = function(block) {
   }
 };
 
-Lua['lists_setIndex'] = function(block) {
+Lua.forBlock['lists_setIndex'] = function(block) {
   // Set element at index.
   // Note: Until February 2013 this block did not have MODE or WHERE inputs.
   let list = Lua.valueToCode(block, 'LIST', Lua.ORDER_HIGH) || '{}';
@@ -223,7 +223,7 @@ Lua['lists_setIndex'] = function(block) {
   return code + '\n';
 };
 
-Lua['lists_getSublist'] = function(block) {
+Lua.forBlock['lists_getSublist'] = function(block) {
   // Get sublist.
   const list = Lua.valueToCode(block, 'LIST', Lua.ORDER_NONE) || '{}';
   const where1 = block.getFieldValue('WHERE1');
@@ -258,7 +258,7 @@ end
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['lists_sort'] = function(block) {
+Lua.forBlock['lists_sort'] = function(block) {
   // Block for sorting a list.
   const list = Lua.valueToCode(block, 'LIST', Lua.ORDER_NONE) || '{}';
   const direction = block.getFieldValue('DIRECTION') === '1' ? 1 : -1;
@@ -292,7 +292,7 @@ end
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['lists_split'] = function(block) {
+Lua.forBlock['lists_split'] = function(block) {
   // Block for splitting text into a list, or joining a list into text.
   let input = Lua.valueToCode(block, 'INPUT', Lua.ORDER_NONE);
   const delimiter = Lua.valueToCode(block, 'DELIM', Lua.ORDER_NONE) || "''";
@@ -331,7 +331,7 @@ end
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['lists_reverse'] = function(block) {
+Lua.forBlock['lists_reverse'] = function(block) {
   // Block for reversing a list.
   const list = Lua.valueToCode(block, 'LIST', Lua.ORDER_NONE) || '{}';
   const functionName = Lua.provideFunction_('list_reverse', `
diff --git a/generators/lua/logic.js b/generators/lua/logic.js
index e0503052d..40cb8f173 100644
--- a/generators/lua/logic.js
+++ b/generators/lua/logic.js
@@ -14,7 +14,7 @@ goog.declareModuleId('Blockly.Lua.logic');
 import {luaGenerator as Lua} from '../lua.js';
 
 
-Lua['controls_if'] = function(block) {
+Lua.forBlock['controls_if'] = function(block) {
   // If/elseif/else condition.
   let n = 0;
   let code = '';
@@ -47,9 +47,9 @@ Lua['controls_if'] = function(block) {
   return code + 'end\n';
 };
 
-Lua['controls_ifelse'] = Lua['controls_if'];
+Lua.forBlock['controls_ifelse'] = Lua.forBlock['controls_if'];
 
-Lua['logic_compare'] = function(block) {
+Lua.forBlock['logic_compare'] = function(block) {
   // Comparison operator.
   const OPERATORS =
       {'EQ': '==', 'NEQ': '~=', 'LT': '<', 'LTE': '<=', 'GT': '>', 'GTE': '>='};
@@ -60,7 +60,7 @@ Lua['logic_compare'] = function(block) {
   return [code, Lua.ORDER_RELATIONAL];
 };
 
-Lua['logic_operation'] = function(block) {
+Lua.forBlock['logic_operation'] = function(block) {
   // Operations 'and', 'or'.
   const operator = (block.getFieldValue('OP') === 'AND') ? 'and' : 'or';
   const order = (operator === 'and') ? Lua.ORDER_AND : Lua.ORDER_OR;
@@ -84,25 +84,25 @@ Lua['logic_operation'] = function(block) {
   return [code, order];
 };
 
-Lua['logic_negate'] = function(block) {
+Lua.forBlock['logic_negate'] = function(block) {
   // Negation.
   const argument0 = Lua.valueToCode(block, 'BOOL', Lua.ORDER_UNARY) || 'true';
   const code = 'not ' + argument0;
   return [code, Lua.ORDER_UNARY];
 };
 
-Lua['logic_boolean'] = function(block) {
+Lua.forBlock['logic_boolean'] = function(block) {
   // Boolean values true and false.
   const code = (block.getFieldValue('BOOL') === 'TRUE') ? 'true' : 'false';
   return [code, Lua.ORDER_ATOMIC];
 };
 
-Lua['logic_null'] = function(block) {
+Lua.forBlock['logic_null'] = function(block) {
   // Null data type.
   return ['nil', Lua.ORDER_ATOMIC];
 };
 
-Lua['logic_ternary'] = function(block) {
+Lua.forBlock['logic_ternary'] = function(block) {
   // Ternary operator.
   const value_if = Lua.valueToCode(block, 'IF', Lua.ORDER_AND) || 'false';
   const value_then = Lua.valueToCode(block, 'THEN', Lua.ORDER_AND) || 'nil';
diff --git a/generators/lua/loops.js b/generators/lua/loops.js
index 7fb8536be..748835b63 100644
--- a/generators/lua/loops.js
+++ b/generators/lua/loops.js
@@ -42,7 +42,7 @@ const addContinueLabel = function(branch) {
   }
 };
 
-Lua['controls_repeat_ext'] = function(block) {
+Lua.forBlock['controls_repeat_ext'] = function(block) {
   // Repeat n times.
   let repeats;
   if (block.getField('TIMES')) {
@@ -66,9 +66,9 @@ Lua['controls_repeat_ext'] = function(block) {
   return code;
 };
 
-Lua['controls_repeat'] = Lua['controls_repeat_ext'];
+Lua.forBlock['controls_repeat'] = Lua.forBlock['controls_repeat_ext'];
 
-Lua['controls_whileUntil'] = function(block) {
+Lua.forBlock['controls_whileUntil'] = function(block) {
   // Do while/until loop.
   const until = block.getFieldValue('MODE') === 'UNTIL';
   let argument0 =
@@ -84,7 +84,7 @@ Lua['controls_whileUntil'] = function(block) {
   return 'while ' + argument0 + ' do\n' + branch + 'end\n';
 };
 
-Lua['controls_for'] = function(block) {
+Lua.forBlock['controls_for'] = function(block) {
   // For loop.
   const variable0 =
       Lua.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -124,7 +124,7 @@ Lua['controls_for'] = function(block) {
   return code;
 };
 
-Lua['controls_forEach'] = function(block) {
+Lua.forBlock['controls_forEach'] = function(block) {
   // For each loop.
   const variable0 =
       Lua.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -137,7 +137,7 @@ Lua['controls_forEach'] = function(block) {
   return code;
 };
 
-Lua['controls_flow_statements'] = function(block) {
+Lua.forBlock['controls_flow_statements'] = function(block) {
   // Flow statements: continue, break.
   let xfix = '';
   if (Lua.STATEMENT_PREFIX) {
diff --git a/generators/lua/math.js b/generators/lua/math.js
index b613e9767..da137f51c 100644
--- a/generators/lua/math.js
+++ b/generators/lua/math.js
@@ -15,14 +15,14 @@ import {NameType} from '../../core/names.js';
 import {luaGenerator as Lua} from '../lua.js';
 
 
-Lua['math_number'] = function(block) {
+Lua.forBlock['math_number'] = function(block) {
   // Numeric value.
   const code = Number(block.getFieldValue('NUM'));
   const order = code < 0 ? Lua.ORDER_UNARY : Lua.ORDER_ATOMIC;
   return [code, order];
 };
 
-Lua['math_arithmetic'] = function(block) {
+Lua.forBlock['math_arithmetic'] = function(block) {
   // Basic arithmetic operators, and power.
   const OPERATORS = {
     'ADD': [' + ', Lua.ORDER_ADDITIVE],
@@ -40,7 +40,7 @@ Lua['math_arithmetic'] = function(block) {
   return [code, order];
 };
 
-Lua['math_single'] = function(block) {
+Lua.forBlock['math_single'] = function(block) {
   // Math operators with single operand.
   const operator = block.getFieldValue('OP');
   let arg;
@@ -110,7 +110,7 @@ Lua['math_single'] = function(block) {
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['math_constant'] = function(block) {
+Lua.forBlock['math_constant'] = function(block) {
   // Constants: PI, E, the Golden Ratio, sqrt(2), 1/sqrt(2), INFINITY.
   const CONSTANTS = {
     'PI': ['math.pi', Lua.ORDER_HIGH],
@@ -123,7 +123,7 @@ Lua['math_constant'] = function(block) {
   return CONSTANTS[block.getFieldValue('CONSTANT')];
 };
 
-Lua['math_number_property'] = function(block) {
+Lua.forBlock['math_number_property'] = function(block) {
   // Check if a number is even, odd, prime, whole, positive, or negative
   // or if it is divisible by certain number. Returns true or false.
   const PROPERTIES = {
@@ -181,7 +181,7 @@ end
   return [code, outputOrder];
 };
 
-Lua['math_change'] = function(block) {
+Lua.forBlock['math_change'] = function(block) {
   // Add to a variable in place.
   const argument0 = Lua.valueToCode(block, 'DELTA', Lua.ORDER_ADDITIVE) || '0';
   const varName =
@@ -190,11 +190,11 @@ Lua['math_change'] = function(block) {
 };
 
 // Rounding functions have a single operand.
-Lua['math_round'] = Lua['math_single'];
+Lua.forBlock['math_round'] = Lua.forBlock['math_single'];
 // Trigonometry functions have a single operand.
-Lua['math_trig'] = Lua['math_single'];
+Lua.forBlock['math_trig'] = Lua.forBlock['math_single'];
 
-Lua['math_on_list'] = function(block) {
+Lua.forBlock['math_on_list'] = function(block) {
   // Math functions for lists.
   const func = block.getFieldValue('OP');
   const list = Lua.valueToCode(block, 'LIST', Lua.ORDER_NONE) || '{}';
@@ -361,7 +361,7 @@ end
   return [functionName + '(' + list + ')', Lua.ORDER_HIGH];
 };
 
-Lua['math_modulo'] = function(block) {
+Lua.forBlock['math_modulo'] = function(block) {
   // Remainder computation.
   const argument0 =
       Lua.valueToCode(block, 'DIVIDEND', Lua.ORDER_MULTIPLICATIVE) || '0';
@@ -371,7 +371,7 @@ Lua['math_modulo'] = function(block) {
   return [code, Lua.ORDER_MULTIPLICATIVE];
 };
 
-Lua['math_constrain'] = function(block) {
+Lua.forBlock['math_constrain'] = function(block) {
   // Constrain a number between two limits.
   const argument0 = Lua.valueToCode(block, 'VALUE', Lua.ORDER_NONE) || '0';
   const argument1 =
@@ -383,7 +383,7 @@ Lua['math_constrain'] = function(block) {
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['math_random_int'] = function(block) {
+Lua.forBlock['math_random_int'] = function(block) {
   // Random integer between [X] and [Y].
   const argument0 = Lua.valueToCode(block, 'FROM', Lua.ORDER_NONE) || '0';
   const argument1 = Lua.valueToCode(block, 'TO', Lua.ORDER_NONE) || '0';
@@ -391,12 +391,12 @@ Lua['math_random_int'] = function(block) {
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['math_random_float'] = function(block) {
+Lua.forBlock['math_random_float'] = function(block) {
   // Random fraction between 0 and 1.
   return ['math.random()', Lua.ORDER_HIGH];
 };
 
-Lua['math_atan2'] = function(block) {
+Lua.forBlock['math_atan2'] = function(block) {
   // Arctangent of point (X, Y) in degrees from -180 to 180.
   const argument0 = Lua.valueToCode(block, 'X', Lua.ORDER_NONE) || '0';
   const argument1 = Lua.valueToCode(block, 'Y', Lua.ORDER_NONE) || '0';
diff --git a/generators/lua/procedures.js b/generators/lua/procedures.js
index 231c583cd..36f5f0059 100644
--- a/generators/lua/procedures.js
+++ b/generators/lua/procedures.js
@@ -15,7 +15,7 @@ import {NameType} from '../../core/names.js';
 import {luaGenerator as Lua} from '../lua.js';
 
 
-Lua['procedures_defreturn'] = function(block) {
+Lua.forBlock['procedures_defreturn'] = function(block) {
   // Define a procedure with a return value.
   const funcName =
       Lua.nameDB_.getName(block.getFieldValue('NAME'), NameType.PROCEDURE);
@@ -61,9 +61,9 @@ Lua['procedures_defreturn'] = function(block) {
 
 // Defining a procedure without a return value uses the same generator as
 // a procedure with a return value.
-Lua['procedures_defnoreturn'] = Lua['procedures_defreturn'];
+Lua.forBlock['procedures_defnoreturn'] = Lua.forBlock['procedures_defreturn'];
 
-Lua['procedures_callreturn'] = function(block) {
+Lua.forBlock['procedures_callreturn'] = function(block) {
   // Call a procedure with a return value.
   const funcName =
       Lua.nameDB_.getName(block.getFieldValue('NAME'), NameType.PROCEDURE);
@@ -76,15 +76,15 @@ Lua['procedures_callreturn'] = function(block) {
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['procedures_callnoreturn'] = function(block) {
+Lua.forBlock['procedures_callnoreturn'] = function(block) {
   // Call a procedure with no return value.
   // Generated code is for a function call as a statement is the same as a
   // function call as a value, with the addition of line ending.
-  const tuple = Lua['procedures_callreturn'](block);
+  const tuple = Lua.forBlock['procedures_callreturn'](block);
   return tuple[0] + '\n';
 };
 
-Lua['procedures_ifreturn'] = function(block) {
+Lua.forBlock['procedures_ifreturn'] = function(block) {
   // Conditionally return value from a procedure.
   const condition =
       Lua.valueToCode(block, 'CONDITION', Lua.ORDER_NONE) || 'false';
diff --git a/generators/lua/text.js b/generators/lua/text.js
index 5e3b05720..cfdacce40 100644
--- a/generators/lua/text.js
+++ b/generators/lua/text.js
@@ -15,13 +15,13 @@ import {NameType} from '../../core/names.js';
 import {luaGenerator as Lua} from '../lua.js';
 
 
-Lua['text'] = function(block) {
+Lua.forBlock['text'] = function(block) {
   // Text value.
   const code = Lua.quote_(block.getFieldValue('TEXT'));
   return [code, Lua.ORDER_ATOMIC];
 };
 
-Lua['text_multiline'] = function(block) {
+Lua.forBlock['text_multiline'] = function(block) {
   // Text value.
   const code = Lua.multiline_quote_(block.getFieldValue('TEXT'));
   const order =
@@ -29,7 +29,7 @@ Lua['text_multiline'] = function(block) {
   return [code, order];
 };
 
-Lua['text_join'] = function(block) {
+Lua.forBlock['text_join'] = function(block) {
   // Create a string made up of any number of elements of any type.
   if (block.itemCount_ === 0) {
     return ["''", Lua.ORDER_ATOMIC];
@@ -54,7 +54,7 @@ Lua['text_join'] = function(block) {
   }
 };
 
-Lua['text_append'] = function(block) {
+Lua.forBlock['text_append'] = function(block) {
   // Append to a variable in place.
   const varName =
       Lua.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -63,19 +63,19 @@ Lua['text_append'] = function(block) {
   return varName + ' = ' + varName + ' .. ' + value + '\n';
 };
 
-Lua['text_length'] = function(block) {
+Lua.forBlock['text_length'] = function(block) {
   // String or array length.
   const text = Lua.valueToCode(block, 'VALUE', Lua.ORDER_UNARY) || "''";
   return ['#' + text, Lua.ORDER_UNARY];
 };
 
-Lua['text_isEmpty'] = function(block) {
+Lua.forBlock['text_isEmpty'] = function(block) {
   // Is the string null or array empty?
   const text = Lua.valueToCode(block, 'VALUE', Lua.ORDER_UNARY) || "''";
   return ['#' + text + ' == 0', Lua.ORDER_RELATIONAL];
 };
 
-Lua['text_indexOf'] = function(block) {
+Lua.forBlock['text_indexOf'] = function(block) {
   // Search the text for a substring.
   const substring = Lua.valueToCode(block, 'FIND', Lua.ORDER_NONE) || "''";
   const text = Lua.valueToCode(block, 'VALUE', Lua.ORDER_NONE) || "''";
@@ -105,7 +105,7 @@ end
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['text_charAt'] = function(block) {
+Lua.forBlock['text_charAt'] = function(block) {
   // Get letter at index.
   // Note: Until January 2013 this block did not have the WHERE input.
   const where = block.getFieldValue('WHERE') || 'FROM_START';
@@ -151,7 +151,7 @@ end
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['text_getSubstring'] = function(block) {
+Lua.forBlock['text_getSubstring'] = function(block) {
   // Get substring.
   const text = Lua.valueToCode(block, 'STRING', Lua.ORDER_NONE) || "''";
 
@@ -188,7 +188,7 @@ Lua['text_getSubstring'] = function(block) {
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['text_changeCase'] = function(block) {
+Lua.forBlock['text_changeCase'] = function(block) {
   // Change capitalization.
   const operator = block.getFieldValue('CASE');
   const text = Lua.valueToCode(block, 'TEXT', Lua.ORDER_NONE) || "''";
@@ -225,7 +225,7 @@ end
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['text_trim'] = function(block) {
+Lua.forBlock['text_trim'] = function(block) {
   // Trim spaces.
   const OPERATORS = {LEFT: '^%s*(,-)', RIGHT: '(.-)%s*$', BOTH: '^%s*(.-)%s*$'};
   const operator = OPERATORS[block.getFieldValue('MODE')];
@@ -234,13 +234,13 @@ Lua['text_trim'] = function(block) {
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['text_print'] = function(block) {
+Lua.forBlock['text_print'] = function(block) {
   // Print statement.
   const msg = Lua.valueToCode(block, 'TEXT', Lua.ORDER_NONE) || "''";
   return 'print(' + msg + ')\n';
 };
 
-Lua['text_prompt_ext'] = function(block) {
+Lua.forBlock['text_prompt_ext'] = function(block) {
   // Prompt function.
   let msg;
   if (block.getField('TEXT')) {
@@ -267,9 +267,9 @@ end
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['text_prompt'] = Lua['text_prompt_ext'];
+Lua.forBlock['text_prompt'] = Lua.forBlock['text_prompt_ext'];
 
-Lua['text_count'] = function(block) {
+Lua.forBlock['text_count'] = function(block) {
   const text = Lua.valueToCode(block, 'TEXT', Lua.ORDER_NONE) || "''";
   const sub = Lua.valueToCode(block, 'SUB', Lua.ORDER_NONE) || "''";
   const functionName = Lua.provideFunction_('text_count', `
@@ -294,7 +294,7 @@ end
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['text_replace'] = function(block) {
+Lua.forBlock['text_replace'] = function(block) {
   const text = Lua.valueToCode(block, 'TEXT', Lua.ORDER_NONE) || "''";
   const from = Lua.valueToCode(block, 'FROM', Lua.ORDER_NONE) || "''";
   const to = Lua.valueToCode(block, 'TO', Lua.ORDER_NONE) || "''";
@@ -320,7 +320,7 @@ end
   return [code, Lua.ORDER_HIGH];
 };
 
-Lua['text_reverse'] = function(block) {
+Lua.forBlock['text_reverse'] = function(block) {
   const text = Lua.valueToCode(block, 'TEXT', Lua.ORDER_NONE) || "''";
   const code = 'string.reverse(' + text + ')';
   return [code, Lua.ORDER_HIGH];
diff --git a/generators/lua/variables.js b/generators/lua/variables.js
index 56283cbcc..7d1df86ab 100644
--- a/generators/lua/variables.js
+++ b/generators/lua/variables.js
@@ -15,14 +15,14 @@ import {NameType} from '../../core/names.js';
 import {luaGenerator as Lua} from '../lua.js';
 
 
-Lua['variables_get'] = function(block) {
+Lua.forBlock['variables_get'] = function(block) {
   // Variable getter.
   const code =
       Lua.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
   return [code, Lua.ORDER_ATOMIC];
 };
 
-Lua['variables_set'] = function(block) {
+Lua.forBlock['variables_set'] = function(block) {
   // Variable setter.
   const argument0 = Lua.valueToCode(block, 'VALUE', Lua.ORDER_NONE) || '0';
   const varName =
diff --git a/generators/lua/variables_dynamic.js b/generators/lua/variables_dynamic.js
index 075fadd82..df08babee 100644
--- a/generators/lua/variables_dynamic.js
+++ b/generators/lua/variables_dynamic.js
@@ -16,5 +16,5 @@ import './variables.js';
 
 
 // Lua is dynamically typed.
-Lua['variables_get_dynamic'] = Lua['variables_get'];
-Lua['variables_set_dynamic'] = Lua['variables_set'];
+Lua.forBlock['variables_get_dynamic'] = Lua.forBlock['variables_get'];
+Lua.forBlock['variables_set_dynamic'] = Lua.forBlock['variables_set'];
diff --git a/generators/php/colour.js b/generators/php/colour.js
index 53a076ee5..149675b93 100644
--- a/generators/php/colour.js
+++ b/generators/php/colour.js
@@ -14,13 +14,13 @@ goog.declareModuleId('Blockly.PHP.colour');
 import {phpGenerator as PHP} from '../php.js';
 
 
-PHP['colour_picker'] = function(block) {
+PHP.forBlock['colour_picker'] = function(block) {
   // Colour picker.
   const code = PHP.quote_(block.getFieldValue('COLOUR'));
   return [code, PHP.ORDER_ATOMIC];
 };
 
-PHP['colour_random'] = function(block) {
+PHP.forBlock['colour_random'] = function(block) {
   // Generate a random colour.
   const functionName = PHP.provideFunction_('colour_random', `
 function ${PHP.FUNCTION_NAME_PLACEHOLDER_}() {
@@ -31,7 +31,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}() {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['colour_rgb'] = function(block) {
+PHP.forBlock['colour_rgb'] = function(block) {
   // Compose a colour from RGB components expressed as percentages.
   const red = PHP.valueToCode(block, 'RED', PHP.ORDER_NONE) || 0;
   const green = PHP.valueToCode(block, 'GREEN', PHP.ORDER_NONE) || 0;
@@ -52,7 +52,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($r, $g, $b) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['colour_blend'] = function(block) {
+PHP.forBlock['colour_blend'] = function(block) {
   // Blend two colours together.
   const c1 = PHP.valueToCode(block, 'COLOUR1', PHP.ORDER_NONE) || "'#000000'";
   const c2 = PHP.valueToCode(block, 'COLOUR2', PHP.ORDER_NONE) || "'#000000'";
diff --git a/generators/php/lists.js b/generators/php/lists.js
index e33ba63b7..c4d180a83 100644
--- a/generators/php/lists.js
+++ b/generators/php/lists.js
@@ -26,12 +26,12 @@ import * as stringUtils from '../../core/utils/string.js';
 import {NameType} from '../../core/names.js';
 import {phpGenerator as PHP} from '../php.js';
 
-PHP['lists_create_empty'] = function(block) {
+PHP.forBlock['lists_create_empty'] = function(block) {
   // Create an empty list.
   return ['array()', PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['lists_create_with'] = function(block) {
+PHP.forBlock['lists_create_with'] = function(block) {
   // Create a list with any number of elements of any type.
   let code = new Array(block.itemCount_);
   for (let i = 0; i < block.itemCount_; i++) {
@@ -41,7 +41,7 @@ PHP['lists_create_with'] = function(block) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['lists_repeat'] = function(block) {
+PHP.forBlock['lists_repeat'] = function(block) {
   // Create a list with one element repeated.
   const functionName = PHP.provideFunction_('lists_repeat', `
 function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($value, $count) {
@@ -58,7 +58,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($value, $count) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['lists_length'] = function(block) {
+PHP.forBlock['lists_length'] = function(block) {
   // String or array length.
   const functionName = PHP.provideFunction_('length', `
 function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($value) {
@@ -73,14 +73,14 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($value) {
   return [functionName + '(' + list + ')', PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['lists_isEmpty'] = function(block) {
+PHP.forBlock['lists_isEmpty'] = function(block) {
   // Is the string null or array empty?
   const argument0 =
       PHP.valueToCode(block, 'VALUE', PHP.ORDER_FUNCTION_CALL) || 'array()';
   return ['empty(' + argument0 + ')', PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['lists_indexOf'] = function(block) {
+PHP.forBlock['lists_indexOf'] = function(block) {
   // Find an item in the list.
   const argument0 = PHP.valueToCode(block, 'FIND', PHP.ORDER_NONE) || "''";
   const argument1 = PHP.valueToCode(block, 'VALUE', PHP.ORDER_MEMBER) || '[]';
@@ -118,7 +118,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($haystack, $needle) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['lists_getIndex'] = function(block) {
+PHP.forBlock['lists_getIndex'] = function(block) {
   // Get element at index.
   const mode = block.getFieldValue('MODE') || 'GET';
   const where = block.getFieldValue('WHERE') || 'FROM_START';
@@ -232,7 +232,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}(&$list) {
   throw Error('Unhandled combination (lists_getIndex).');
 };
 
-PHP['lists_setIndex'] = function(block) {
+PHP.forBlock['lists_setIndex'] = function(block) {
   // Set element at index.
   // Note: Until February 2013 this block did not have MODE or WHERE inputs.
   const mode = block.getFieldValue('MODE') || 'GET';
@@ -328,7 +328,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}(&$list, $at, $value) {
   throw Error('Unhandled combination (lists_setIndex).');
 };
 
-PHP['lists_getSublist'] = function(block) {
+PHP.forBlock['lists_getSublist'] = function(block) {
   // Get sublist.
   const list = PHP.valueToCode(block, 'LIST', PHP.ORDER_NONE) || 'array()';
   const where1 = block.getFieldValue('WHERE1');
@@ -424,7 +424,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($list, $where1, $at1, $where2, $at2)
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['lists_sort'] = function(block) {
+PHP.forBlock['lists_sort'] = function(block) {
   // Block for sorting a list.
   const listCode = PHP.valueToCode(block, 'LIST', PHP.ORDER_NONE) || 'array()';
   const direction = block.getFieldValue('DIRECTION') === '1' ? 1 : -1;
@@ -450,7 +450,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($list, $type, $direction) {
   return [sortCode, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['lists_split'] = function(block) {
+PHP.forBlock['lists_split'] = function(block) {
   // Block for splitting text into a list, or joining a list into text.
   let value_input = PHP.valueToCode(block, 'INPUT', PHP.ORDER_NONE);
   const value_delim = PHP.valueToCode(block, 'DELIM', PHP.ORDER_NONE) || "''";
@@ -473,7 +473,7 @@ PHP['lists_split'] = function(block) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['lists_reverse'] = function(block) {
+PHP.forBlock['lists_reverse'] = function(block) {
   // Block for reversing a list.
   const list = PHP.valueToCode(block, 'LIST', PHP.ORDER_NONE) || '[]';
   const code = 'array_reverse(' + list + ')';
diff --git a/generators/php/logic.js b/generators/php/logic.js
index fe4a2f566..7bd4c49a2 100644
--- a/generators/php/logic.js
+++ b/generators/php/logic.js
@@ -14,7 +14,7 @@ goog.declareModuleId('Blockly.PHP.logic');
 import {phpGenerator as PHP} from '../php.js';
 
 
-PHP['controls_if'] = function(block) {
+PHP.forBlock['controls_if'] = function(block) {
   // If/elseif/else condition.
   let n = 0;
   let code = '', branchCode, conditionCode;
@@ -47,9 +47,9 @@ PHP['controls_if'] = function(block) {
   return code + '\n';
 };
 
-PHP['controls_ifelse'] = PHP['controls_if'];
+PHP.forBlock['controls_ifelse'] = PHP.forBlock['controls_if'];
 
-PHP['logic_compare'] = function(block) {
+PHP.forBlock['logic_compare'] = function(block) {
   // Comparison operator.
   const OPERATORS =
       {'EQ': '==', 'NEQ': '!=', 'LT': '<', 'LTE': '<=', 'GT': '>', 'GTE': '>='};
@@ -62,7 +62,7 @@ PHP['logic_compare'] = function(block) {
   return [code, order];
 };
 
-PHP['logic_operation'] = function(block) {
+PHP.forBlock['logic_operation'] = function(block) {
   // Operations 'and', 'or'.
   const operator = (block.getFieldValue('OP') === 'AND') ? '&&' : '||';
   const order =
@@ -87,7 +87,7 @@ PHP['logic_operation'] = function(block) {
   return [code, order];
 };
 
-PHP['logic_negate'] = function(block) {
+PHP.forBlock['logic_negate'] = function(block) {
   // Negation.
   const order = PHP.ORDER_LOGICAL_NOT;
   const argument0 = PHP.valueToCode(block, 'BOOL', order) || 'true';
@@ -95,18 +95,18 @@ PHP['logic_negate'] = function(block) {
   return [code, order];
 };
 
-PHP['logic_boolean'] = function(block) {
+PHP.forBlock['logic_boolean'] = function(block) {
   // Boolean values true and false.
   const code = (block.getFieldValue('BOOL') === 'TRUE') ? 'true' : 'false';
   return [code, PHP.ORDER_ATOMIC];
 };
 
-PHP['logic_null'] = function(block) {
+PHP.forBlock['logic_null'] = function(block) {
   // Null data type.
   return ['null', PHP.ORDER_ATOMIC];
 };
 
-PHP['logic_ternary'] = function(block) {
+PHP.forBlock['logic_ternary'] = function(block) {
   // Ternary operator.
   const value_if =
       PHP.valueToCode(block, 'IF', PHP.ORDER_CONDITIONAL) || 'false';
diff --git a/generators/php/loops.js b/generators/php/loops.js
index fd8e1c219..a1fc5bb2d 100644
--- a/generators/php/loops.js
+++ b/generators/php/loops.js
@@ -16,7 +16,7 @@ import {NameType} from '../../core/names.js';
 import {phpGenerator as PHP} from '../php.js';
 
 
-PHP['controls_repeat_ext'] = function(block) {
+PHP.forBlock['controls_repeat_ext'] = function(block) {
   // Repeat n times.
   let repeats;
   if (block.getField('TIMES')) {
@@ -40,9 +40,9 @@ PHP['controls_repeat_ext'] = function(block) {
   return code;
 };
 
-PHP['controls_repeat'] = PHP['controls_repeat_ext'];
+PHP.forBlock['controls_repeat'] = PHP.forBlock['controls_repeat_ext'];
 
-PHP['controls_whileUntil'] = function(block) {
+PHP.forBlock['controls_whileUntil'] = function(block) {
   // Do while/until loop.
   const until = block.getFieldValue('MODE') === 'UNTIL';
   let argument0 =
@@ -57,7 +57,7 @@ PHP['controls_whileUntil'] = function(block) {
   return 'while (' + argument0 + ') {\n' + branch + '}\n';
 };
 
-PHP['controls_for'] = function(block) {
+PHP.forBlock['controls_for'] = function(block) {
   // For loop.
   const variable0 =
       PHP.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -116,7 +116,7 @@ PHP['controls_for'] = function(block) {
   return code;
 };
 
-PHP['controls_forEach'] = function(block) {
+PHP.forBlock['controls_forEach'] = function(block) {
   // For each loop.
   const variable0 =
       PHP.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -130,7 +130,7 @@ PHP['controls_forEach'] = function(block) {
   return code;
 };
 
-PHP['controls_flow_statements'] = function(block) {
+PHP.forBlock['controls_flow_statements'] = function(block) {
   // Flow statements: continue, break.
   let xfix = '';
   if (PHP.STATEMENT_PREFIX) {
diff --git a/generators/php/math.js b/generators/php/math.js
index 8efcb5318..6eb2d944f 100644
--- a/generators/php/math.js
+++ b/generators/php/math.js
@@ -15,7 +15,7 @@ import {NameType} from '../../core/names.js';
 import {phpGenerator as PHP} from '../php.js';
 
 
-PHP['math_number'] = function(block) {
+PHP.forBlock['math_number'] = function(block) {
   // Numeric value.
   let code = Number(block.getFieldValue('NUM'));
   const order = code >= 0 ? PHP.ORDER_ATOMIC : PHP.ORDER_UNARY_NEGATION;
@@ -27,7 +27,7 @@ PHP['math_number'] = function(block) {
   return [code, order];
 };
 
-PHP['math_arithmetic'] = function(block) {
+PHP.forBlock['math_arithmetic'] = function(block) {
   // Basic arithmetic operators, and power.
   const OPERATORS = {
     'ADD': [' + ', PHP.ORDER_ADDITION],
@@ -45,7 +45,7 @@ PHP['math_arithmetic'] = function(block) {
   return [code, order];
 };
 
-PHP['math_single'] = function(block) {
+PHP.forBlock['math_single'] = function(block) {
   // Math operators with single operand.
   const operator = block.getFieldValue('OP');
   let code;
@@ -126,7 +126,7 @@ PHP['math_single'] = function(block) {
   return [code, PHP.ORDER_DIVISION];
 };
 
-PHP['math_constant'] = function(block) {
+PHP.forBlock['math_constant'] = function(block) {
   // Constants: PI, E, the Golden Ratio, sqrt(2), 1/sqrt(2), INFINITY.
   const CONSTANTS = {
     'PI': ['M_PI', PHP.ORDER_ATOMIC],
@@ -139,7 +139,7 @@ PHP['math_constant'] = function(block) {
   return CONSTANTS[block.getFieldValue('CONSTANT')];
 };
 
-PHP['math_number_property'] = function(block) {
+PHP.forBlock['math_number_property'] = function(block) {
   // Check if a number is even, odd, prime, whole, positive, or negative
   // or if it is divisible by certain number. Returns true or false.
   const PROPERTIES = {
@@ -193,7 +193,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($n) {
   return [code, outputOrder];
 };
 
-PHP['math_change'] = function(block) {
+PHP.forBlock['math_change'] = function(block) {
   // Add to a variable in place.
   const argument0 = PHP.valueToCode(block, 'DELTA', PHP.ORDER_ADDITION) || '0';
   const varName =
@@ -202,11 +202,11 @@ PHP['math_change'] = function(block) {
 };
 
 // Rounding functions have a single operand.
-PHP['math_round'] = PHP['math_single'];
+PHP.forBlock['math_round'] = PHP.forBlock['math_single'];
 // Trigonometry functions have a single operand.
-PHP['math_trig'] = PHP['math_single'];
+PHP.forBlock['math_trig'] = PHP.forBlock['math_single'];
 
-PHP['math_on_list'] = function(block) {
+PHP.forBlock['math_on_list'] = function(block) {
   // Math functions for lists.
   const func = block.getFieldValue('OP');
   let list;
@@ -297,7 +297,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($list) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['math_modulo'] = function(block) {
+PHP.forBlock['math_modulo'] = function(block) {
   // Remainder computation.
   const argument0 =
       PHP.valueToCode(block, 'DIVIDEND', PHP.ORDER_MODULUS) || '0';
@@ -306,7 +306,7 @@ PHP['math_modulo'] = function(block) {
   return [code, PHP.ORDER_MODULUS];
 };
 
-PHP['math_constrain'] = function(block) {
+PHP.forBlock['math_constrain'] = function(block) {
   // Constrain a number between two limits.
   const argument0 = PHP.valueToCode(block, 'VALUE', PHP.ORDER_NONE) || '0';
   const argument1 = PHP.valueToCode(block, 'LOW', PHP.ORDER_NONE) || '0';
@@ -317,7 +317,7 @@ PHP['math_constrain'] = function(block) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['math_random_int'] = function(block) {
+PHP.forBlock['math_random_int'] = function(block) {
   // Random integer between [X] and [Y].
   const argument0 = PHP.valueToCode(block, 'FROM', PHP.ORDER_NONE) || '0';
   const argument1 = PHP.valueToCode(block, 'TO', PHP.ORDER_NONE) || '0';
@@ -333,12 +333,12 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($a, $b) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['math_random_float'] = function(block) {
+PHP.forBlock['math_random_float'] = function(block) {
   // Random fraction between 0 and 1.
   return ['(float)rand()/(float)getrandmax()', PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['math_atan2'] = function(block) {
+PHP.forBlock['math_atan2'] = function(block) {
   // Arctangent of point (X, Y) in degrees from -180 to 180.
   const argument0 = PHP.valueToCode(block, 'X', PHP.ORDER_NONE) || '0';
   const argument1 = PHP.valueToCode(block, 'Y', PHP.ORDER_NONE) || '0';
diff --git a/generators/php/procedures.js b/generators/php/procedures.js
index 7c77f90c3..12bdbf3a3 100644
--- a/generators/php/procedures.js
+++ b/generators/php/procedures.js
@@ -16,7 +16,7 @@ import {NameType} from '../../core/names.js';
 import {phpGenerator as PHP} from '../php.js';
 
 
-PHP['procedures_defreturn'] = function(block) {
+PHP.forBlock['procedures_defreturn'] = function(block) {
   // Define a procedure with a return value.
   // First, add a 'global' statement for every variable that is not shadowed by
   // a local parameter.
@@ -80,9 +80,9 @@ PHP['procedures_defreturn'] = function(block) {
 
 // Defining a procedure without a return value uses the same generator as
 // a procedure with a return value.
-PHP['procedures_defnoreturn'] = PHP['procedures_defreturn'];
+PHP.forBlock['procedures_defnoreturn'] = PHP.forBlock['procedures_defreturn'];
 
-PHP['procedures_callreturn'] = function(block) {
+PHP.forBlock['procedures_callreturn'] = function(block) {
   // Call a procedure with a return value.
   const funcName =
       PHP.nameDB_.getName(block.getFieldValue('NAME'), NameType.PROCEDURE);
@@ -95,15 +95,15 @@ PHP['procedures_callreturn'] = function(block) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['procedures_callnoreturn'] = function(block) {
+PHP.forBlock['procedures_callnoreturn'] = function(block) {
   // Call a procedure with no return value.
   // Generated code is for a function call as a statement is the same as a
   // function call as a value, with the addition of line ending.
-  const tuple = PHP['procedures_callreturn'](block);
+  const tuple = PHP.forBlock['procedures_callreturn'](block);
   return tuple[0] + ';\n';
 };
 
-PHP['procedures_ifreturn'] = function(block) {
+PHP.forBlock['procedures_ifreturn'] = function(block) {
   // Conditionally return value from a procedure.
   const condition =
       PHP.valueToCode(block, 'CONDITION', PHP.ORDER_NONE) || 'false';
diff --git a/generators/php/text.js b/generators/php/text.js
index 84254a30a..83c10a5dd 100644
--- a/generators/php/text.js
+++ b/generators/php/text.js
@@ -15,13 +15,13 @@ import {NameType} from '../../core/names.js';
 import {phpGenerator as PHP} from '../php.js';
 
 
-PHP['text'] = function(block) {
+PHP.forBlock['text'] = function(block) {
   // Text value.
   const code = PHP.quote_(block.getFieldValue('TEXT'));
   return [code, PHP.ORDER_ATOMIC];
 };
 
-PHP['text_multiline'] = function(block) {
+PHP.forBlock['text_multiline'] = function(block) {
   // Text value.
   const code = PHP.multiline_quote_(block.getFieldValue('TEXT'));
   const order =
@@ -29,7 +29,7 @@ PHP['text_multiline'] = function(block) {
   return [code, order];
 };
 
-PHP['text_join'] = function(block) {
+PHP.forBlock['text_join'] = function(block) {
   // Create a string made up of any number of elements of any type.
   if (block.itemCount_ === 0) {
     return ["''", PHP.ORDER_ATOMIC];
@@ -54,7 +54,7 @@ PHP['text_join'] = function(block) {
   }
 };
 
-PHP['text_append'] = function(block) {
+PHP.forBlock['text_append'] = function(block) {
   // Append to a variable in place.
   const varName =
       PHP.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -62,7 +62,7 @@ PHP['text_append'] = function(block) {
   return varName + ' .= ' + value + ';\n';
 };
 
-PHP['text_length'] = function(block) {
+PHP.forBlock['text_length'] = function(block) {
   // String or array length.
   const functionName = PHP.provideFunction_('length', `
 function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($value) {
@@ -76,13 +76,13 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($value) {
   return [functionName + '(' + text + ')', PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['text_isEmpty'] = function(block) {
+PHP.forBlock['text_isEmpty'] = function(block) {
   // Is the string null or array empty?
   const text = PHP.valueToCode(block, 'VALUE', PHP.ORDER_NONE) || "''";
   return ['empty(' + text + ')', PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['text_indexOf'] = function(block) {
+PHP.forBlock['text_indexOf'] = function(block) {
   // Search the text for a substring.
   const operator =
       block.getFieldValue('END') === 'FIRST' ? 'strpos' : 'strrpos';
@@ -107,7 +107,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($text, $search) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['text_charAt'] = function(block) {
+PHP.forBlock['text_charAt'] = function(block) {
   // Get letter at index.
   const where = block.getFieldValue('WHERE') || 'FROM_START';
   const textOrder = (where === 'RANDOM') ? PHP.ORDER_NONE : PHP.ORDER_NONE;
@@ -144,7 +144,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($text) {
   throw Error('Unhandled option (text_charAt).');
 };
 
-PHP['text_getSubstring'] = function(block) {
+PHP.forBlock['text_getSubstring'] = function(block) {
   // Get substring.
   const where1 = block.getFieldValue('WHERE1');
   const where2 = block.getFieldValue('WHERE2');
@@ -183,7 +183,7 @@ function ${PHP.FUNCTION_NAME_PLACEHOLDER_}($text, $where1, $at1, $where2, $at2)
   }
 };
 
-PHP['text_changeCase'] = function(block) {
+PHP.forBlock['text_changeCase'] = function(block) {
   // Change capitalization.
   const text = PHP.valueToCode(block, 'TEXT', PHP.ORDER_NONE) || "''";
   let code;
@@ -197,7 +197,7 @@ PHP['text_changeCase'] = function(block) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['text_trim'] = function(block) {
+PHP.forBlock['text_trim'] = function(block) {
   // Trim spaces.
   const OPERATORS = {'LEFT': 'ltrim', 'RIGHT': 'rtrim', 'BOTH': 'trim'};
   const operator = OPERATORS[block.getFieldValue('MODE')];
@@ -205,13 +205,13 @@ PHP['text_trim'] = function(block) {
   return [operator + '(' + text + ')', PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['text_print'] = function(block) {
+PHP.forBlock['text_print'] = function(block) {
   // Print statement.
   const msg = PHP.valueToCode(block, 'TEXT', PHP.ORDER_NONE) || "''";
   return 'print(' + msg + ');\n';
 };
 
-PHP['text_prompt_ext'] = function(block) {
+PHP.forBlock['text_prompt_ext'] = function(block) {
   // Prompt function.
   let msg;
   if (block.getField('TEXT')) {
@@ -229,9 +229,9 @@ PHP['text_prompt_ext'] = function(block) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['text_prompt'] = PHP['text_prompt_ext'];
+PHP.forBlock['text_prompt'] = PHP.forBlock['text_prompt_ext'];
 
-PHP['text_count'] = function(block) {
+PHP.forBlock['text_count'] = function(block) {
   const text = PHP.valueToCode(block, 'TEXT', PHP.ORDER_NONE) || "''";
   const sub = PHP.valueToCode(block, 'SUB', PHP.ORDER_NONE) || "''";
   const code = 'strlen(' + sub + ') === 0' +
@@ -240,7 +240,7 @@ PHP['text_count'] = function(block) {
   return [code, PHP.ORDER_CONDITIONAL];
 };
 
-PHP['text_replace'] = function(block) {
+PHP.forBlock['text_replace'] = function(block) {
   const text = PHP.valueToCode(block, 'TEXT', PHP.ORDER_NONE) || "''";
   const from = PHP.valueToCode(block, 'FROM', PHP.ORDER_NONE) || "''";
   const to = PHP.valueToCode(block, 'TO', PHP.ORDER_NONE) || "''";
@@ -248,7 +248,7 @@ PHP['text_replace'] = function(block) {
   return [code, PHP.ORDER_FUNCTION_CALL];
 };
 
-PHP['text_reverse'] = function(block) {
+PHP.forBlock['text_reverse'] = function(block) {
   const text = PHP.valueToCode(block, 'TEXT', PHP.ORDER_NONE) || "''";
   const code = 'strrev(' + text + ')';
   return [code, PHP.ORDER_FUNCTION_CALL];
diff --git a/generators/php/variables.js b/generators/php/variables.js
index fb35d8c9c..50f4a9e9b 100644
--- a/generators/php/variables.js
+++ b/generators/php/variables.js
@@ -15,14 +15,14 @@ import {NameType} from '../../core/names.js';
 import {phpGenerator as PHP} from '../php.js';
 
 
-PHP['variables_get'] = function(block) {
+PHP.forBlock['variables_get'] = function(block) {
   // Variable getter.
   const code =
       PHP.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
   return [code, PHP.ORDER_ATOMIC];
 };
 
-PHP['variables_set'] = function(block) {
+PHP.forBlock['variables_set'] = function(block) {
   // Variable setter.
   const argument0 =
       PHP.valueToCode(block, 'VALUE', PHP.ORDER_ASSIGNMENT) || '0';
diff --git a/generators/php/variables_dynamic.js b/generators/php/variables_dynamic.js
index 8116c69b2..88732aebc 100644
--- a/generators/php/variables_dynamic.js
+++ b/generators/php/variables_dynamic.js
@@ -16,5 +16,5 @@ import './variables.js';
 
 
 // PHP is dynamically typed.
-PHP['variables_get_dynamic'] = PHP['variables_get'];
-PHP['variables_set_dynamic'] = PHP['variables_set'];
+PHP.forBlock['variables_get_dynamic'] = PHP.forBlock['variables_get'];
+PHP.forBlock['variables_set_dynamic'] = PHP.forBlock['variables_set'];
diff --git a/generators/python/colour.js b/generators/python/colour.js
index 7912cc7e2..2c5f9ac15 100644
--- a/generators/python/colour.js
+++ b/generators/python/colour.js
@@ -14,20 +14,20 @@ goog.declareModuleId('Blockly.Python.colour');
 import {pythonGenerator as Python} from '../python.js';
 
 
-Python['colour_picker'] = function(block) {
+Python.forBlock['colour_picker'] = function(block) {
   // Colour picker.
   const code = Python.quote_(block.getFieldValue('COLOUR'));
   return [code, Python.ORDER_ATOMIC];
 };
 
-Python['colour_random'] = function(block) {
+Python.forBlock['colour_random'] = function(block) {
   // Generate a random colour.
   Python.definitions_['import_random'] = 'import random';
   const code = '\'#%06x\' % random.randint(0, 2**24 - 1)';
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['colour_rgb'] = function(block) {
+Python.forBlock['colour_rgb'] = function(block) {
   // Compose a colour from RGB components expressed as percentages.
   const functionName = Python.provideFunction_('colour_rgb', `
 def ${Python.FUNCTION_NAME_PLACEHOLDER_}(r, g, b):
@@ -43,7 +43,7 @@ def ${Python.FUNCTION_NAME_PLACEHOLDER_}(r, g, b):
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['colour_blend'] = function(block) {
+Python.forBlock['colour_blend'] = function(block) {
   // Blend two colours together.
   const functionName = Python.provideFunction_('colour_blend', `
 def ${Python.FUNCTION_NAME_PLACEHOLDER_}(colour1, colour2, ratio):
diff --git a/generators/python/lists.js b/generators/python/lists.js
index 74a78e838..f7fc5cd6c 100644
--- a/generators/python/lists.js
+++ b/generators/python/lists.js
@@ -16,12 +16,12 @@ import {NameType} from '../../core/names.js';
 import {pythonGenerator as Python} from '../python.js';
 
 
-Python['lists_create_empty'] = function(block) {
+Python.forBlock['lists_create_empty'] = function(block) {
   // Create an empty list.
   return ['[]', Python.ORDER_ATOMIC];
 };
 
-Python['lists_create_with'] = function(block) {
+Python.forBlock['lists_create_with'] = function(block) {
   // Create a list with any number of elements of any type.
   const elements = new Array(block.itemCount_);
   for (let i = 0; i < block.itemCount_; i++) {
@@ -32,7 +32,7 @@ Python['lists_create_with'] = function(block) {
   return [code, Python.ORDER_ATOMIC];
 };
 
-Python['lists_repeat'] = function(block) {
+Python.forBlock['lists_repeat'] = function(block) {
   // Create a list with one element repeated.
   const item = Python.valueToCode(block, 'ITEM', Python.ORDER_NONE) || 'None';
   const times =
@@ -41,20 +41,20 @@ Python['lists_repeat'] = function(block) {
   return [code, Python.ORDER_MULTIPLICATIVE];
 };
 
-Python['lists_length'] = function(block) {
+Python.forBlock['lists_length'] = function(block) {
   // String or array length.
   const list = Python.valueToCode(block, 'VALUE', Python.ORDER_NONE) || '[]';
   return ['len(' + list + ')', Python.ORDER_FUNCTION_CALL];
 };
 
-Python['lists_isEmpty'] = function(block) {
+Python.forBlock['lists_isEmpty'] = function(block) {
   // Is the string null or array empty?
   const list = Python.valueToCode(block, 'VALUE', Python.ORDER_NONE) || '[]';
   const code = 'not len(' + list + ')';
   return [code, Python.ORDER_LOGICAL_NOT];
 };
 
-Python['lists_indexOf'] = function(block) {
+Python.forBlock['lists_indexOf'] = function(block) {
   // Find an item in the list.
   const item = Python.valueToCode(block, 'FIND', Python.ORDER_NONE) || '[]';
   const list = Python.valueToCode(block, 'VALUE', Python.ORDER_NONE) || "''";
@@ -88,7 +88,7 @@ def ${Python.FUNCTION_NAME_PLACEHOLDER_}(my_list, elem):
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['lists_getIndex'] = function(block) {
+Python.forBlock['lists_getIndex'] = function(block) {
   // Get element at index.
   // Note: Until January 2013 this block did not have MODE or WHERE inputs.
   const mode = block.getFieldValue('MODE') || 'GET';
@@ -170,7 +170,7 @@ def ${Python.FUNCTION_NAME_PLACEHOLDER_}(myList):
   throw Error('Unhandled combination (lists_getIndex).');
 };
 
-Python['lists_setIndex'] = function(block) {
+Python.forBlock['lists_setIndex'] = function(block) {
   // Set element at index.
   // Note: Until February 2013 this block did not have MODE or WHERE inputs.
   let list = Python.valueToCode(block, 'LIST', Python.ORDER_MEMBER) || '[]';
@@ -241,7 +241,7 @@ Python['lists_setIndex'] = function(block) {
   throw Error('Unhandled combination (lists_setIndex).');
 };
 
-Python['lists_getSublist'] = function(block) {
+Python.forBlock['lists_getSublist'] = function(block) {
   // Get sublist.
   const list = Python.valueToCode(block, 'LIST', Python.ORDER_MEMBER) || '[]';
   const where1 = block.getFieldValue('WHERE1');
@@ -290,7 +290,7 @@ Python['lists_getSublist'] = function(block) {
   return [code, Python.ORDER_MEMBER];
 };
 
-Python['lists_sort'] = function(block) {
+Python.forBlock['lists_sort'] = function(block) {
   // Block for sorting a list.
   const list = (Python.valueToCode(block, 'LIST', Python.ORDER_NONE) || '[]');
   const type = block.getFieldValue('TYPE');
@@ -317,7 +317,7 @@ def ${Python.FUNCTION_NAME_PLACEHOLDER_}(my_list, type, reverse):
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['lists_split'] = function(block) {
+Python.forBlock['lists_split'] = function(block) {
   // Block for splitting text into a list, or joining a list into text.
   const mode = block.getFieldValue('MODE');
   let code;
@@ -338,7 +338,7 @@ Python['lists_split'] = function(block) {
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['lists_reverse'] = function(block) {
+Python.forBlock['lists_reverse'] = function(block) {
   // Block for reversing a list.
   const list = Python.valueToCode(block, 'LIST', Python.ORDER_NONE) || '[]';
   const code = 'list(reversed(' + list + '))';
diff --git a/generators/python/logic.js b/generators/python/logic.js
index 8aa8476b8..e78009c50 100644
--- a/generators/python/logic.js
+++ b/generators/python/logic.js
@@ -14,7 +14,7 @@ goog.declareModuleId('Blockly.Python.logic');
 import {pythonGenerator as Python} from '../python.js';
 
 
-Python['controls_if'] = function(block) {
+Python.forBlock['controls_if'] = function(block) {
   // If/elseif/else condition.
   let n = 0;
   let code = '', branchCode, conditionCode;
@@ -49,9 +49,9 @@ Python['controls_if'] = function(block) {
   return code;
 };
 
-Python['controls_ifelse'] = Python['controls_if'];
+Python.forBlock['controls_ifelse'] = Python.forBlock['controls_if'];
 
-Python['logic_compare'] = function(block) {
+Python.forBlock['logic_compare'] = function(block) {
   // Comparison operator.
   const OPERATORS =
       {'EQ': '==', 'NEQ': '!=', 'LT': '<', 'LTE': '<=', 'GT': '>', 'GTE': '>='};
@@ -63,7 +63,7 @@ Python['logic_compare'] = function(block) {
   return [code, order];
 };
 
-Python['logic_operation'] = function(block) {
+Python.forBlock['logic_operation'] = function(block) {
   // Operations 'and', 'or'.
   const operator = (block.getFieldValue('OP') === 'AND') ? 'and' : 'or';
   const order =
@@ -88,7 +88,7 @@ Python['logic_operation'] = function(block) {
   return [code, order];
 };
 
-Python['logic_negate'] = function(block) {
+Python.forBlock['logic_negate'] = function(block) {
   // Negation.
   const argument0 =
       Python.valueToCode(block, 'BOOL', Python.ORDER_LOGICAL_NOT) || 'True';
@@ -96,18 +96,18 @@ Python['logic_negate'] = function(block) {
   return [code, Python.ORDER_LOGICAL_NOT];
 };
 
-Python['logic_boolean'] = function(block) {
+Python.forBlock['logic_boolean'] = function(block) {
   // Boolean values true and false.
   const code = (block.getFieldValue('BOOL') === 'TRUE') ? 'True' : 'False';
   return [code, Python.ORDER_ATOMIC];
 };
 
-Python['logic_null'] = function(block) {
+Python.forBlock['logic_null'] = function(block) {
   // Null data type.
   return ['None', Python.ORDER_ATOMIC];
 };
 
-Python['logic_ternary'] = function(block) {
+Python.forBlock['logic_ternary'] = function(block) {
   // Ternary operator.
   const value_if =
       Python.valueToCode(block, 'IF', Python.ORDER_CONDITIONAL) || 'False';
diff --git a/generators/python/loops.js b/generators/python/loops.js
index c554914b2..2bb22c289 100644
--- a/generators/python/loops.js
+++ b/generators/python/loops.js
@@ -16,7 +16,7 @@ import {NameType} from '../../core/names.js';
 import {pythonGenerator as Python} from '../python.js';
 
 
-Python['controls_repeat_ext'] = function(block) {
+Python.forBlock['controls_repeat_ext'] = function(block) {
   // Repeat n times.
   let repeats;
   if (block.getField('TIMES')) {
@@ -38,9 +38,9 @@ Python['controls_repeat_ext'] = function(block) {
   return code;
 };
 
-Python['controls_repeat'] = Python['controls_repeat_ext'];
+Python.forBlock['controls_repeat'] = Python.forBlock['controls_repeat_ext'];
 
-Python['controls_whileUntil'] = function(block) {
+Python.forBlock['controls_whileUntil'] = function(block) {
   // Do while/until loop.
   const until = block.getFieldValue('MODE') === 'UNTIL';
   let argument0 = Python.valueToCode(
@@ -55,7 +55,7 @@ Python['controls_whileUntil'] = function(block) {
   return 'while ' + argument0 + ':\n' + branch;
 };
 
-Python['controls_for'] = function(block) {
+Python.forBlock['controls_for'] = function(block) {
   // For loop.
   const variable0 =
       Python.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -163,7 +163,7 @@ def ${Python.FUNCTION_NAME_PLACEHOLDER_}(start, stop, step):
   return code;
 };
 
-Python['controls_forEach'] = function(block) {
+Python.forBlock['controls_forEach'] = function(block) {
   // For each loop.
   const variable0 =
       Python.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -175,7 +175,7 @@ Python['controls_forEach'] = function(block) {
   return code;
 };
 
-Python['controls_flow_statements'] = function(block) {
+Python.forBlock['controls_flow_statements'] = function(block) {
   // Flow statements: continue, break.
   let xfix = '';
   if (Python.STATEMENT_PREFIX) {
diff --git a/generators/python/math.js b/generators/python/math.js
index 8c1d0b8dd..0366a608a 100644
--- a/generators/python/math.js
+++ b/generators/python/math.js
@@ -18,7 +18,7 @@ import {pythonGenerator as Python} from '../python.js';
 // If any new block imports any library, add that library name here.
 Python.addReservedWords('math,random,Number');
 
-Python['math_number'] = function(block) {
+Python.forBlock['math_number'] = function(block) {
   // Numeric value.
   let code = Number(block.getFieldValue('NUM'));
   let order;
@@ -34,7 +34,7 @@ Python['math_number'] = function(block) {
   return [code, order];
 };
 
-Python['math_arithmetic'] = function(block) {
+Python.forBlock['math_arithmetic'] = function(block) {
   // Basic arithmetic operators, and power.
   const OPERATORS = {
     'ADD': [' + ', Python.ORDER_ADDITIVE],
@@ -57,7 +57,7 @@ Python['math_arithmetic'] = function(block) {
   // legibility of the generated code.
 };
 
-Python['math_single'] = function(block) {
+Python.forBlock['math_single'] = function(block) {
   // Math operators with single operand.
   const operator = block.getFieldValue('OP');
   let code;
@@ -134,7 +134,7 @@ Python['math_single'] = function(block) {
   return [code, Python.ORDER_MULTIPLICATIVE];
 };
 
-Python['math_constant'] = function(block) {
+Python.forBlock['math_constant'] = function(block) {
   // Constants: PI, E, the Golden Ratio, sqrt(2), 1/sqrt(2), INFINITY.
   const CONSTANTS = {
     'PI': ['math.pi', Python.ORDER_MEMBER],
@@ -151,7 +151,7 @@ Python['math_constant'] = function(block) {
   return CONSTANTS[constant];
 };
 
-Python['math_number_property'] = function(block) {
+Python.forBlock['math_number_property'] = function(block) {
    // Check if a number is even, odd, prime, whole, positive, or negative
    // or if it is divisible by certain number. Returns true or false.
   const PROPERTIES = {
@@ -210,7 +210,7 @@ def ${Python.FUNCTION_NAME_PLACEHOLDER_}(n):
   return [code, outputOrder];
 };
 
-Python['math_change'] = function(block) {
+Python.forBlock['math_change'] = function(block) {
   // Add to a variable in place.
   Python.definitions_['from_numbers_import_Number'] =
       'from numbers import Number';
@@ -223,11 +223,11 @@ Python['math_change'] = function(block) {
 };
 
 // Rounding functions have a single operand.
-Python['math_round'] = Python['math_single'];
+Python.forBlock['math_round'] = Python.forBlock['math_single'];
 // Trigonometry functions have a single operand.
-Python['math_trig'] = Python['math_single'];
+Python.forBlock['math_trig'] = Python.forBlock['math_single'];
 
-Python['math_on_list'] = function(block) {
+Python.forBlock['math_on_list'] = function(block) {
   // Math functions for lists.
   const func = block.getFieldValue('OP');
   const list = Python.valueToCode(block, 'LIST', Python.ORDER_NONE) || '[]';
@@ -324,7 +324,7 @@ def ${Python.FUNCTION_NAME_PLACEHOLDER_}(numbers):
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['math_modulo'] = function(block) {
+Python.forBlock['math_modulo'] = function(block) {
   // Remainder computation.
   const argument0 =
       Python.valueToCode(block, 'DIVIDEND', Python.ORDER_MULTIPLICATIVE) || '0';
@@ -334,7 +334,7 @@ Python['math_modulo'] = function(block) {
   return [code, Python.ORDER_MULTIPLICATIVE];
 };
 
-Python['math_constrain'] = function(block) {
+Python.forBlock['math_constrain'] = function(block) {
   // Constrain a number between two limits.
   const argument0 =
       Python.valueToCode(block, 'VALUE', Python.ORDER_NONE) || '0';
@@ -346,7 +346,7 @@ Python['math_constrain'] = function(block) {
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['math_random_int'] = function(block) {
+Python.forBlock['math_random_int'] = function(block) {
   // Random integer between [X] and [Y].
   Python.definitions_['import_random'] = 'import random';
   const argument0 = Python.valueToCode(block, 'FROM', Python.ORDER_NONE) || '0';
@@ -355,13 +355,13 @@ Python['math_random_int'] = function(block) {
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['math_random_float'] = function(block) {
+Python.forBlock['math_random_float'] = function(block) {
   // Random fraction between 0 and 1.
   Python.definitions_['import_random'] = 'import random';
   return ['random.random()', Python.ORDER_FUNCTION_CALL];
 };
 
-Python['math_atan2'] = function(block) {
+Python.forBlock['math_atan2'] = function(block) {
   // Arctangent of point (X, Y) in degrees from -180 to 180.
   Python.definitions_['import_math'] = 'import math';
   const argument0 = Python.valueToCode(block, 'X', Python.ORDER_NONE) || '0';
diff --git a/generators/python/procedures.js b/generators/python/procedures.js
index cd4a9d7ec..4c893bd2a 100644
--- a/generators/python/procedures.js
+++ b/generators/python/procedures.js
@@ -16,7 +16,7 @@ import {NameType} from '../../core/names.js';
 import {pythonGenerator as Python} from '../python.js';
 
 
-Python['procedures_defreturn'] = function(block) {
+Python.forBlock['procedures_defreturn'] = function(block) {
   // Define a procedure with a return value.
   // First, add a 'global' statement for every variable that is not shadowed by
   // a local parameter.
@@ -84,9 +84,9 @@ Python['procedures_defreturn'] = function(block) {
 
 // Defining a procedure without a return value uses the same generator as
 // a procedure with a return value.
-Python['procedures_defnoreturn'] = Python['procedures_defreturn'];
+Python.forBlock['procedures_defnoreturn'] = Python.forBlock['procedures_defreturn'];
 
-Python['procedures_callreturn'] = function(block) {
+Python.forBlock['procedures_callreturn'] = function(block) {
   // Call a procedure with a return value.
   const funcName =
       Python.nameDB_.getName(block.getFieldValue('NAME'), NameType.PROCEDURE);
@@ -99,15 +99,15 @@ Python['procedures_callreturn'] = function(block) {
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['procedures_callnoreturn'] = function(block) {
+Python.forBlock['procedures_callnoreturn'] = function(block) {
   // Call a procedure with no return value.
   // Generated code is for a function call as a statement is the same as a
   // function call as a value, with the addition of line ending.
-  const tuple = Python['procedures_callreturn'](block);
+  const tuple = Python.forBlock['procedures_callreturn'](block);
   return tuple[0] + '\n';
 };
 
-Python['procedures_ifreturn'] = function(block) {
+Python.forBlock['procedures_ifreturn'] = function(block) {
   // Conditionally return value from a procedure.
   const condition =
       Python.valueToCode(block, 'CONDITION', Python.ORDER_NONE) || 'False';
diff --git a/generators/python/text.js b/generators/python/text.js
index e6ec889cd..1258a905f 100644
--- a/generators/python/text.js
+++ b/generators/python/text.js
@@ -16,13 +16,13 @@ import {NameType} from '../../core/names.js';
 import {pythonGenerator as Python} from '../python.js';
 
 
-Python['text'] = function(block) {
+Python.forBlock['text'] = function(block) {
   // Text value.
   const code = Python.quote_(block.getFieldValue('TEXT'));
   return [code, Python.ORDER_ATOMIC];
 };
 
-Python['text_multiline'] = function(block) {
+Python.forBlock['text_multiline'] = function(block) {
   // Text value.
   const code = Python.multiline_quote_(block.getFieldValue('TEXT'));
   const order =
@@ -50,7 +50,7 @@ const forceString = function(value) {
   return ['str(' + value + ')', Python.ORDER_FUNCTION_CALL];
 };
 
-Python['text_join'] = function(block) {
+Python.forBlock['text_join'] = function(block) {
   // Create a string made up of any number of elements of any type.
   // Should we allow joining by '-' or ',' or any other characters?
   switch (block.itemCount_) {
@@ -84,7 +84,7 @@ Python['text_join'] = function(block) {
   }
 };
 
-Python['text_append'] = function(block) {
+Python.forBlock['text_append'] = function(block) {
   // Append to a variable in place.
   const varName =
       Python.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
@@ -92,20 +92,20 @@ Python['text_append'] = function(block) {
   return varName + ' = str(' + varName + ') + ' + forceString(value)[0] + '\n';
 };
 
-Python['text_length'] = function(block) {
+Python.forBlock['text_length'] = function(block) {
   // Is the string null or array empty?
   const text = Python.valueToCode(block, 'VALUE', Python.ORDER_NONE) || "''";
   return ['len(' + text + ')', Python.ORDER_FUNCTION_CALL];
 };
 
-Python['text_isEmpty'] = function(block) {
+Python.forBlock['text_isEmpty'] = function(block) {
   // Is the string null or array empty?
   const text = Python.valueToCode(block, 'VALUE', Python.ORDER_NONE) || "''";
   const code = 'not len(' + text + ')';
   return [code, Python.ORDER_LOGICAL_NOT];
 };
 
-Python['text_indexOf'] = function(block) {
+Python.forBlock['text_indexOf'] = function(block) {
   // Search the text for a substring.
   // Should we allow for non-case sensitive???
   const operator = block.getFieldValue('END') === 'FIRST' ? 'find' : 'rfind';
@@ -120,7 +120,7 @@ Python['text_indexOf'] = function(block) {
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['text_charAt'] = function(block) {
+Python.forBlock['text_charAt'] = function(block) {
   // Get letter at index.
   // Note: Until January 2013 this block did not have the WHERE input.
   const where = block.getFieldValue('WHERE') || 'FROM_START';
@@ -160,7 +160,7 @@ def ${Python.FUNCTION_NAME_PLACEHOLDER_}(text):
   throw Error('Unhandled option (text_charAt).');
 };
 
-Python['text_getSubstring'] = function(block) {
+Python.forBlock['text_getSubstring'] = function(block) {
   // Get substring.
   const where1 = block.getFieldValue('WHERE1');
   const where2 = block.getFieldValue('WHERE2');
@@ -210,7 +210,7 @@ Python['text_getSubstring'] = function(block) {
   return [code, Python.ORDER_MEMBER];
 };
 
-Python['text_changeCase'] = function(block) {
+Python.forBlock['text_changeCase'] = function(block) {
   // Change capitalization.
   const OPERATORS = {
     'UPPERCASE': '.upper()',
@@ -223,7 +223,7 @@ Python['text_changeCase'] = function(block) {
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['text_trim'] = function(block) {
+Python.forBlock['text_trim'] = function(block) {
   // Trim spaces.
   const OPERATORS = {
     'LEFT': '.lstrip()',
@@ -236,13 +236,13 @@ Python['text_trim'] = function(block) {
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['text_print'] = function(block) {
+Python.forBlock['text_print'] = function(block) {
   // Print statement.
   const msg = Python.valueToCode(block, 'TEXT', Python.ORDER_NONE) || "''";
   return 'print(' + msg + ')\n';
 };
 
-Python['text_prompt_ext'] = function(block) {
+Python.forBlock['text_prompt_ext'] = function(block) {
   // Prompt function.
   const functionName = Python.provideFunction_('text_prompt', `
 def ${Python.FUNCTION_NAME_PLACEHOLDER_}(msg):
@@ -267,16 +267,16 @@ def ${Python.FUNCTION_NAME_PLACEHOLDER_}(msg):
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['text_prompt'] = Python['text_prompt_ext'];
+Python.forBlock['text_prompt'] = Python.forBlock['text_prompt_ext'];
 
-Python['text_count'] = function(block) {
+Python.forBlock['text_count'] = function(block) {
   const text = Python.valueToCode(block, 'TEXT', Python.ORDER_MEMBER) || "''";
   const sub = Python.valueToCode(block, 'SUB', Python.ORDER_NONE) || "''";
   const code = text + '.count(' + sub + ')';
   return [code, Python.ORDER_FUNCTION_CALL];
 };
 
-Python['text_replace'] = function(block) {
+Python.forBlock['text_replace'] = function(block) {
   const text = Python.valueToCode(block, 'TEXT', Python.ORDER_MEMBER) || "''";
   const from = Python.valueToCode(block, 'FROM', Python.ORDER_NONE) || "''";
   const to = Python.valueToCode(block, 'TO', Python.ORDER_NONE) || "''";
@@ -284,7 +284,7 @@ Python['text_replace'] = function(block) {
   return [code, Python.ORDER_MEMBER];
 };
 
-Python['text_reverse'] = function(block) {
+Python.forBlock['text_reverse'] = function(block) {
   const text = Python.valueToCode(block, 'TEXT', Python.ORDER_MEMBER) || "''";
   const code = text + '[::-1]';
   return [code, Python.ORDER_MEMBER];
diff --git a/generators/python/variables.js b/generators/python/variables.js
index 58f0a3e1a..bd13ec15c 100644
--- a/generators/python/variables.js
+++ b/generators/python/variables.js
@@ -15,14 +15,14 @@ import {NameType} from '../../core/names.js';
 import {pythonGenerator as Python} from '../python.js';
 
 
-Python['variables_get'] = function(block) {
+Python.forBlock['variables_get'] = function(block) {
   // Variable getter.
   const code =
       Python.nameDB_.getName(block.getFieldValue('VAR'), NameType.VARIABLE);
   return [code, Python.ORDER_ATOMIC];
 };
 
-Python['variables_set'] = function(block) {
+Python.forBlock['variables_set'] = function(block) {
   // Variable setter.
   const argument0 =
       Python.valueToCode(block, 'VALUE', Python.ORDER_NONE) || '0';
diff --git a/generators/python/variables_dynamic.js b/generators/python/variables_dynamic.js
index cfa6785e4..e091f45d9 100644
--- a/generators/python/variables_dynamic.js
+++ b/generators/python/variables_dynamic.js
@@ -16,5 +16,5 @@ import './variables.js';
 
 
 // Python is dynamically typed.
-Python['variables_get_dynamic'] = Python['variables_get'];
-Python['variables_set_dynamic'] = Python['variables_set'];
+Python.forBlock['variables_get_dynamic'] = Python.forBlock['variables_get'];
+Python.forBlock['variables_set_dynamic'] = Python.forBlock['variables_set'];
diff --git a/tests/mocha/generator_test.js b/tests/mocha/generator_test.js
index 1f34d5a7d..869bfab6d 100644
--- a/tests/mocha/generator_test.js
+++ b/tests/mocha/generator_test.js
@@ -87,16 +87,18 @@ suite('Generator', function () {
         expectedCode,
         opt_message
       ) {
-        generator.row_block = function (_) {
+        generator.forBlock['row_block'] = function (_) {
           return 'row_block';
         };
-        generator.stack_block = function (_) {
+        generator.forBlock['stack_block'] = function (_) {
           return 'stack_block';
         };
         rowBlock.nextConnection.connect(stackBlock.previousConnection);
         rowBlock.disabled = blockDisabled;
 
         const code = generator.blockToCode(rowBlock, opt_thisOnly);
+        delete generator.forBlock['stack_block'];
+        delete generator.forBlock['row_block'];
         chai.assert.equal(code, expectedCode, opt_message);
       };
     });
@@ -170,7 +172,7 @@ suite('Generator', function () {
           expectedCode,
           opt_message
         ) {
-          generator.test_loop_block = function (block) {
+          generator.forBlock['test_loop_block'] = function (block) {
             return '{' + generator.statementToCode(block, 'DO') + '}';
           };
           blockA.getInput('DO').connection.connect(blockB.previousConnection);
diff --git a/tests/mocha/insertion_marker_test.js b/tests/mocha/insertion_marker_test.js
index bb73fd813..f59c735df 100644
--- a/tests/mocha/insertion_marker_test.js
+++ b/tests/mocha/insertion_marker_test.js
@@ -52,10 +52,10 @@ suite('InsertionMarkers', function () {
   });
   suite('Code Generation', function () {
     setup(function () {
-      javascriptGenerator['stack_block'] = function (block) {
+      javascriptGenerator.forBlock['stack_block'] = function (block) {
         return 'stack[' + block.id + '];\n';
       };
-      javascriptGenerator['row_block'] = function (block) {
+      javascriptGenerator.forBlock['row_block'] = function (block) {
         const value = javascriptGenerator.valueToCode(
           block,
           'INPUT',
@@ -64,7 +64,7 @@ suite('InsertionMarkers', function () {
         const code = 'row[' + block.id + '](' + value + ')';
         return [code, javascriptGenerator.ORDER_NONE];
       };
-      javascriptGenerator['statement_block'] = function (block) {
+      javascriptGenerator.forBlock['statement_block'] = function (block) {
         return (
           'statement[' +
           block.id +
@@ -83,9 +83,9 @@ suite('InsertionMarkers', function () {
       };
     });
     teardown(function () {
-      delete javascriptGenerator['stack_block'];
-      delete javascriptGenerator['row_block'];
-      delete javascriptGenerator['statement_block'];
+      delete javascriptGenerator.forBlock['stack_block'];
+      delete javascriptGenerator.forBlock['row_block'];
+      delete javascriptGenerator.forBlock['statement_block'];
     });
     test('Marker Surrounds', function () {
       const xml = Blockly.utils.xml.textToDom(