Files
blockly/generators/python/python_generator.ts
Neil Fraser 0ecbcde9fc chore: Use .includes and .startsWith, not .indexOf (#7936)
Easier to read than the diverse collection of `=== 0` and `!== -1` and `> -1` tests.
2024-03-15 00:03:55 +01:00

357 lines
13 KiB
TypeScript

/**
* @license
* Copyright 2012 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file Python code generator class, including helper methods for
* generating Python for blocks.
*/
// Former goog.module ID: Blockly.Python
import * as stringUtils from '../../core/utils/string.js';
import * as Variables from '../../core/variables.js';
import type {Block} from '../../core/block.js';
import {CodeGenerator} from '../../core/generator.js';
import {Names} from '../../core/names.js';
import type {Workspace} from '../../core/workspace.js';
import {inputTypes} from '../../core/inputs/input_types.js';
/**
* Order of operation ENUMs.
* http://docs.python.org/reference/expressions.html#summary
*/
// prettier-ignore
export enum Order {
ATOMIC = 0, // 0 "" ...
COLLECTION = 1, // tuples, lists, dictionaries
STRING_CONVERSION = 1, // `expression...`
MEMBER = 2.1, // . []
FUNCTION_CALL = 2.2, // ()
EXPONENTIATION = 3, // **
UNARY_SIGN = 4, // + -
BITWISE_NOT = 4, // ~
MULTIPLICATIVE = 5, // * / // %
ADDITIVE = 6, // + -
BITWISE_SHIFT = 7, // << >>
BITWISE_AND = 8, // &
BITWISE_XOR = 9, // ^
BITWISE_OR = 10, // |
RELATIONAL = 11, // in, not in, is, is not, >, >=, <>, !=, ==
LOGICAL_NOT = 12, // not
LOGICAL_AND = 13, // and
LOGICAL_OR = 14, // or
CONDITIONAL = 15, // if else
LAMBDA = 16, // lambda
NONE = 99, // (...)
}
/**
* PythonScript code generator class.
*/
export class PythonGenerator extends CodeGenerator {
/** List of outer-inner pairings that do NOT require parentheses. */
ORDER_OVERRIDES: [Order, Order][] = [
// (foo()).bar -> foo().bar
// (foo())[0] -> foo()[0]
[Order.FUNCTION_CALL, Order.MEMBER],
// (foo())() -> foo()()
[Order.FUNCTION_CALL, Order.FUNCTION_CALL],
// (foo.bar).baz -> foo.bar.baz
// (foo.bar)[0] -> foo.bar[0]
// (foo[0]).bar -> foo[0].bar
// (foo[0])[1] -> foo[0][1]
[Order.MEMBER, Order.MEMBER],
// (foo.bar)() -> foo.bar()
// (foo[0])() -> foo[0]()
[Order.MEMBER, Order.FUNCTION_CALL],
// not (not foo) -> not not foo
[Order.LOGICAL_NOT, Order.LOGICAL_NOT],
// a and (b and c) -> a and b and c
[Order.LOGICAL_AND, Order.LOGICAL_AND],
// a or (b or c) -> a or b or c
[Order.LOGICAL_OR, Order.LOGICAL_OR],
];
/**
* Empty loops or conditionals are not allowed in Python.
*/
PASS: string = ''; // Initialised by init().
/** @param name Name of the language the generator is for. */
constructor(name = 'Python') {
super(name);
this.isInitialized = false;
// Copy Order values onto instance for backwards compatibility
// while ensuring they are not part of the publically-advertised
// API.
//
// TODO(#7085): deprecate these in due course. (Could initially
// replace data properties with get accessors that call
// deprecate.warn().)
for (const key in Order) {
// Must assign Order[key] to a temporary to get the type guard to work;
// see https://github.com/microsoft/TypeScript/issues/10530.
const value = Order[key];
// Skip reverse-lookup entries in the enum. Due to
// https://github.com/microsoft/TypeScript/issues/55713 this (as
// of TypeScript 5.5.2) actually narrows the type of value to
// never - but that still allows the following assignment to
// succeed.
if (typeof value === 'string') continue;
(this as unknown as Record<string, Order>)['ORDER_' + key] = value;
}
// List of illegal variable names. This is not intended to be a
// security feature. Blockly is 100% client-side, so bypassing
// this list is trivial. This is intended to prevent users from
// accidentally clobbering a built-in object or function.
this.addReservedWords(
// import keyword
// print(','.join(sorted(keyword.kwlist)))
// https://docs.python.org/3/reference/lexical_analysis.html#keywords
// https://docs.python.org/2/reference/lexical_analysis.html#keywords
'False,None,True,and,as,assert,break,class,continue,def,del,elif,else,' +
'except,exec,finally,for,from,global,if,import,in,is,lambda,nonlocal,' +
'not,or,pass,print,raise,return,try,while,with,yield,' +
// https://docs.python.org/3/library/constants.html
// https://docs.python.org/2/library/constants.html
'NotImplemented,Ellipsis,__debug__,quit,exit,copyright,license,credits,' +
// >>> print(','.join(sorted(dir(__builtins__))))
// https://docs.python.org/3/library/functions.html
// https://docs.python.org/2/library/functions.html
'ArithmeticError,AssertionError,AttributeError,BaseException,' +
'BlockingIOError,BrokenPipeError,BufferError,BytesWarning,' +
'ChildProcessError,ConnectionAbortedError,ConnectionError,' +
'ConnectionRefusedError,ConnectionResetError,DeprecationWarning,' +
'EOFError,Ellipsis,EnvironmentError,Exception,FileExistsError,' +
'FileNotFoundError,FloatingPointError,FutureWarning,GeneratorExit,' +
'IOError,ImportError,ImportWarning,IndentationError,IndexError,' +
'InterruptedError,IsADirectoryError,KeyError,KeyboardInterrupt,' +
'LookupError,MemoryError,ModuleNotFoundError,NameError,' +
'NotADirectoryError,NotImplemented,NotImplementedError,OSError,' +
'OverflowError,PendingDeprecationWarning,PermissionError,' +
'ProcessLookupError,RecursionError,ReferenceError,ResourceWarning,' +
'RuntimeError,RuntimeWarning,StandardError,StopAsyncIteration,' +
'StopIteration,SyntaxError,SyntaxWarning,SystemError,SystemExit,' +
'TabError,TimeoutError,TypeError,UnboundLocalError,UnicodeDecodeError,' +
'UnicodeEncodeError,UnicodeError,UnicodeTranslateError,UnicodeWarning,' +
'UserWarning,ValueError,Warning,ZeroDivisionError,_,__build_class__,' +
'__debug__,__doc__,__import__,__loader__,__name__,__package__,__spec__,' +
'abs,all,any,apply,ascii,basestring,bin,bool,buffer,bytearray,bytes,' +
'callable,chr,classmethod,cmp,coerce,compile,complex,copyright,credits,' +
'delattr,dict,dir,divmod,enumerate,eval,exec,execfile,exit,file,filter,' +
'float,format,frozenset,getattr,globals,hasattr,hash,help,hex,id,input,' +
'int,intern,isinstance,issubclass,iter,len,license,list,locals,long,' +
'map,max,memoryview,min,next,object,oct,open,ord,pow,print,property,' +
'quit,range,raw_input,reduce,reload,repr,reversed,round,set,setattr,' +
'slice,sorted,staticmethod,str,sum,super,tuple,type,unichr,unicode,' +
'vars,xrange,zip',
);
}
/**
* Initialise the database of variable names.
*
* @param workspace Workspace to generate code from.
*/
init(workspace: Workspace) {
super.init(workspace);
this.PASS = this.INDENT + 'pass\n';
if (!this.nameDB_) {
this.nameDB_ = new Names(this.RESERVED_WORDS_);
} else {
this.nameDB_.reset();
}
this.nameDB_.setVariableMap(workspace.getVariableMap());
this.nameDB_.populateVariables(workspace);
this.nameDB_.populateProcedures(workspace);
const defvars = [];
// Add developer variables (not created or named by the user).
const devVarList = Variables.allDeveloperVariables(workspace);
for (let i = 0; i < devVarList.length; i++) {
defvars.push(
this.nameDB_.getName(devVarList[i], Names.DEVELOPER_VARIABLE_TYPE) +
' = None',
);
}
// Add user variables, but only ones that are being used.
const variables = Variables.allUsedVarModels(workspace);
for (let i = 0; i < variables.length; i++) {
defvars.push(this.getVariableName(variables[i].getId()) + ' = None');
}
this.definitions_['variables'] = defvars.join('\n');
this.isInitialized = true;
}
/**
* Prepend the generated code with import statements and variable definitions.
*
* @param code Generated code.
* @returns Completed code.
*/
finish(code: string): string {
// Convert the definitions dictionary into a list.
const imports = [];
const definitions = [];
for (let name in this.definitions_) {
const def = this.definitions_[name];
if (def.match(/^(from\s+\S+\s+)?import\s+\S+/)) {
imports.push(def);
} else {
definitions.push(def);
}
}
// Call Blockly.CodeGenerator's finish.
code = super.finish(code);
this.isInitialized = false;
this.nameDB_!.reset();
const allDefs = imports.join('\n') + '\n\n' + definitions.join('\n\n');
return allDefs.replace(/\n\n+/g, '\n\n').replace(/\n*$/, '\n\n\n') + code;
}
/**
* Naked values are top-level blocks with outputs that aren't plugged into
* anything.
*
* @param line Line of generated code.
* @returns Legal line of code.
*/
scrubNakedValue(line: string): string {
return line + '\n';
}
/**
* Encode a string as a properly escaped Python string, complete with quotes.
*
* @param string Text to encode.
* @returns Python string.
*/
quote_(string: string): string {
string = string.replace(/\\/g, '\\\\').replace(/\n/g, '\\\n');
// Follow the CPython behaviour of repr() for a non-byte string.
let quote = "'";
if (string.includes("'")) {
if (!string.includes('"')) {
quote = '"';
} else {
string = string.replace(/'/g, "\\'");
}
}
return quote + string + quote;
}
/**
* Encode a string as a properly escaped multiline Python string, complete
* with quotes.
*
* @param string Text to encode.
* @returns Python string.
*/
multiline_quote_(string: string): string {
const lines = string.split(/\n/g).map(this.quote_);
// Join with the following, plus a newline:
// + '\n' +
return lines.join(" + '\\n' + \n");
}
/**
* Common tasks for generating Python from blocks.
* Handles comments for the specified block and any connected value blocks.
* Calls any statements following this block.
*
* @param block The current block.
* @param code The Python code created for this block.
* @param thisOnly True to generate code for only this statement.
* @returns Python code with comments and subsequent blocks added.
*/
scrub_(block: Block, code: string, thisOnly = false): string {
let commentCode = '';
// Only collect comments for blocks that aren't inline.
if (!block.outputConnection || !block.outputConnection.targetConnection) {
// Collect comment for this block.
let comment = block.getCommentText();
if (comment) {
comment = stringUtils.wrap(comment, this.COMMENT_WRAP - 3);
commentCode += this.prefixLines(comment + '\n', '# ');
}
// Collect comments for all value arguments.
// Don't collect comments for nested statements.
for (let i = 0; i < block.inputList.length; i++) {
if (block.inputList[i].type === inputTypes.VALUE) {
const childBlock = block.inputList[i].connection!.targetBlock();
if (childBlock) {
comment = this.allNestedComments(childBlock);
if (comment) {
commentCode += this.prefixLines(comment, '# ');
}
}
}
}
}
const nextBlock =
block.nextConnection && block.nextConnection.targetBlock();
const nextCode = thisOnly ? '' : this.blockToCode(nextBlock);
return commentCode + code + nextCode;
}
/**
* Gets a property and adjusts the value, taking into account indexing.
* If a static int, casts to an integer, otherwise returns a code string.
*
* @param block The block.
* @param atId The ID of the input block to get (and adjust) the value of.
* @param delta Value to add.
* @param negate Whether to negate the value.
* @returns The adjusted value or code that evaluates to it.
*/
getAdjustedInt(
block: Block,
atId: string,
delta = 0,
negate = false,
): string | number {
if (block.workspace.options.oneBasedIndex) {
delta--;
}
const defaultAtIndex = block.workspace.options.oneBasedIndex ? '1' : '0';
const atOrder = delta ? Order.ADDITIVE : Order.NONE;
let at: string | number =
this.valueToCode(block, atId, atOrder) || defaultAtIndex;
if (stringUtils.isNumber(at)) {
// If the index is a naked number, adjust it right now.
at = parseInt(at, 10) + delta;
if (negate) {
at = -at;
}
} else {
// If the index is dynamic, adjust it in code.
if (delta > 0) {
at = 'int(' + at + ' + ' + delta + ')';
} else if (delta < 0) {
at = 'int(' + at + ' - ' + -delta + ')';
} else {
at = 'int(' + at + ')';
}
if (negate) {
at = '-' + at;
}
}
return at;
}
}