blockly/generators/dart/procedures.js

/**
 * @license
 * Copyright 2014 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @fileoverview Generating Dart for procedure blocks.
 */

// Former goog.module ID: Blockly.Dart.procedures

import {Order} from './dart_generator.js';


export function procedures_defreturn(block, generator) {
  // Define a procedure with a return value.
  const funcName =
      generator.getProcedureName(block.getFieldValue('NAME'));
  let xfix1 = '';
  if (generator.STATEMENT_PREFIX) {
    xfix1 += generator.injectId(generator.STATEMENT_PREFIX, block);
  }
  if (generator.STATEMENT_SUFFIX) {
    xfix1 += generator.injectId(generator.STATEMENT_SUFFIX, block);
  }
  if (xfix1) {
    xfix1 = generator.prefixLines(xfix1, generator.INDENT);
  }
  let loopTrap = '';
  if (generator.INFINITE_LOOP_TRAP) {
    loopTrap = generator.prefixLines(
        generator.injectId(generator.INFINITE_LOOP_TRAP, block),
        generator.INDENT);
  }
  const branch = generator.statementToCode(block, 'STACK');
  let returnValue =
      generator.valueToCode(block, 'RETURN', Order.NONE) || '';
  let xfix2 = '';
  if (branch && returnValue) {
    // After executing the function body, revisit this block for the return.
    xfix2 = xfix1;
  }
  if (returnValue) {
    returnValue = generator.INDENT + 'return ' + returnValue + ';\n';
  }
  const returnType = returnValue ? 'dynamic' : 'void';
  const args = [];
  const variables = block.getVars();
  for (let i = 0; i < variables.length; i++) {
    args[i] = generator.getVariableName(variables[i]);
  }
  let code = returnType + ' ' + funcName + '(' + args.join(', ') + ') {\n' +
      xfix1 + loopTrap + branch + xfix2 + returnValue + '}';
  code = generator.scrub_(block, code);
  // Add % so as not to collide with helper functions in definitions list.
  generator.definitions_['%' + funcName] = code;
  return null;
};

// Defining a procedure without a return value uses the same generator as
// a procedure with a return value.
export const procedures_defnoreturn = procedures_defreturn;

export function procedures_callreturn(block, generator) {
  // Call a procedure with a return value.
  const funcName =
      generator.getProcedureName(block.getFieldValue('NAME'));
  const args = [];
  const variables = block.getVars();
  for (let i = 0; i < variables.length; i++) {
    args[i] = generator.valueToCode(block, 'ARG' + i, Order.NONE) || 'null';
  }
  let code = funcName + '(' + args.join(', ') + ')';
  return [code, Order.UNARY_POSTFIX];
};

export function procedures_callnoreturn(block, generator) {
  // 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 = generator.forBlock['procedures_callreturn'](block, generator);
  return tuple[0] + ';\n';
};

export function procedures_ifreturn(block, generator) {
  // Conditionally return value from a procedure.
  const condition =
      generator.valueToCode(block, 'CONDITION', Order.NONE) || 'false';
  let code = 'if (' + condition + ') {\n';
  if (generator.STATEMENT_SUFFIX) {
    // Inject any statement suffix here since the regular one at the end
    // will not get executed if the return is triggered.
    code += generator.prefixLines(
        generator.injectId(
          generator.STATEMENT_SUFFIX, block), generator.INDENT);
  }
  if (block.hasReturnValue_) {
    const value =
        generator.valueToCode(block, 'VALUE', Order.NONE) || 'null';
    code += generator.INDENT + 'return ' + value + ';\n';
  } else {
    code += generator.INDENT + 'return;\n';
  }
  code += '}\n';
  return code;
};