generators/python/procedures.js
/**
* @license
* Visual Blocks Language
*
* Copyright 2012 Google Inc.
* https://blockly.googlecode.com/
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @fileoverview Generating Python for procedure blocks.
* @author fraser@google.com (Neil Fraser)
*/
'use strict';
goog.provide('Blockly.Python.procedures');
goog.require('Blockly.Python');
Blockly.Python['procedures_defreturn'] = function(block) {
// Define a procedure with a return value.
// First, add a 'global' statement for every variable that is assigned.
var globals = Blockly.Variables.allVariables(block);
for (var i = globals.length - 1; i >= 0; i--) {
var varName = globals[i];
if (block.arguments_.indexOf(varName) == -1) {
globals[i] = Blockly.Python.variableDB_.getName(varName,
Blockly.Variables.NAME_TYPE);
} else {
// This variable is actually a parameter name. Do not include it in
// the list of globals, thus allowing it be of local scope.
globals.splice(i, 1);
}
}
globals = globals.length ? ' global ' + globals.join(', ') + '\n' : '';
var funcName = Blockly.Python.variableDB_.getName(block.getFieldValue('NAME'),
Blockly.Procedures.NAME_TYPE);
var branch = Blockly.Python.statementToCode(block, 'STACK');
if (Blockly.Python.STATEMENT_PREFIX) {
branch = Blockly.Python.prefixLines(
Blockly.Python.STATEMENT_PREFIX.replace(/%1/g,
'\'' + block.id + '\''), Blockly.Python.INDENT) + branch;
}
if (Blockly.Python.INFINITE_LOOP_TRAP) {
branch = Blockly.Python.INFINITE_LOOP_TRAP.replace(/%1/g,
'"' + block.id + '"') + branch;
}
var returnValue = Blockly.Python.valueToCode(block, 'RETURN',
Blockly.Python.ORDER_NONE) || '';
if (returnValue) {
returnValue = ' return ' + returnValue + '\n';
} else if (!branch) {
branch = ' pass';
}
var args = [];
for (var x = 0; x < block.arguments_.length; x++) {
args[x] = Blockly.Python.variableDB_.getName(block.arguments_[x],
Blockly.Variables.NAME_TYPE);
}
var code = 'def ' + funcName + '(' + args.join(', ') + '):\n' +
globals + branch + returnValue;
code = Blockly.Python.scrub_(block, code);
Blockly.Python.definitions_[funcName] = code;
return null;
};
// Defining a procedure without a return value uses the same generator as
// a procedure with a return value.
Blockly.Python['procedures_defnoreturn'] =
Blockly.Python['procedures_defreturn'];
Blockly.Python['procedures_callreturn'] = function(block) {
// Call a procedure with a return value.
var funcName = Blockly.Python.variableDB_.getName(block.getFieldValue('NAME'),
Blockly.Procedures.NAME_TYPE);
var args = [];
for (var x = 0; x < block.arguments_.length; x++) {
args[x] = Blockly.Python.valueToCode(block, 'ARG' + x,
Blockly.Python.ORDER_NONE) || 'None';
}
var code = funcName + '(' + args.join(', ') + ')';
return [code, Blockly.Python.ORDER_FUNCTION_CALL];
};
Blockly.Python['procedures_callnoreturn'] = function(block) {
// Call a procedure with no return value.
var funcName = Blockly.Python.variableDB_.getName(block.getFieldValue('NAME'),
Blockly.Procedures.NAME_TYPE);
var args = [];
for (var x = 0; x < block.arguments_.length; x++) {
args[x] = Blockly.Python.valueToCode(block, 'ARG' + x,
Blockly.Python.ORDER_NONE) || 'None';
}
var code = funcName + '(' + args.join(', ') + ')\n';
return code;
};
Blockly.Python['procedures_ifreturn'] = function(block) {
// Conditionally return value from a procedure.
var condition = Blockly.Python.valueToCode(block, 'CONDITION',
Blockly.Python.ORDER_NONE) || 'False';
var code = 'if ' + condition + ':\n';
if (block.hasReturnValue_) {
var value = Blockly.Python.valueToCode(block, 'VALUE',
Blockly.Python.ORDER_NONE) || 'None';
code += ' return ' + value + '\n';
} else {
code += ' return\n';
}
return code;
};