generators/python.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 Helper functions for generating Python for blocks.
* @author fraser@google.com (Neil Fraser)
*/
'use strict';
goog.provide('Blockly.Python');
goog.require('Blockly.Generator');
Blockly.Python = new Blockly.Generator('Python');
/**
* 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.
* @private
*/
Blockly.Python.addReservedWords(
// import keyword
// print ','.join(keyword.kwlist)
// http://docs.python.org/reference/lexical_analysis.html#keywords
'and,as,assert,break,class,continue,def,del,elif,else,except,exec,finally,for,from,global,if,import,in,is,lambda,not,or,pass,print,raise,return,try,while,with,yield,' +
//http://docs.python.org/library/constants.html
'True,False,None,NotImplemented,Ellipsis,__debug__,quit,exit,copyright,license,credits,' +
// http://docs.python.org/library/functions.html
'abs,divmod,input,open,staticmethod,all,enumerate,int,ord,str,any,eval,isinstance,pow,sum,basestring,execfile,issubclass,print,super,bin,file,iter,property,tuple,bool,filter,len,range,type,bytearray,float,list,raw_input,unichr,callable,format,locals,reduce,unicode,chr,frozenset,long,reload,vars,classmethod,getattr,map,repr,xrange,cmp,globals,max,reversed,zip,compile,hasattr,memoryview,round,__import__,complex,hash,min,set,apply,delattr,help,next,setattr,buffer,dict,hex,object,slice,coerce,dir,id,oct,sorted,intern');
/**
* Order of operation ENUMs.
* http://docs.python.org/reference/expressions.html#summary
*/
Blockly.Python.ORDER_ATOMIC = 0; // 0 "" ...
Blockly.Python.ORDER_COLLECTION = 1; // tuples, lists, dictionaries
Blockly.Python.ORDER_STRING_CONVERSION = 1; // `expression...`
Blockly.Python.ORDER_MEMBER = 2; // . []
Blockly.Python.ORDER_FUNCTION_CALL = 2; // ()
Blockly.Python.ORDER_EXPONENTIATION = 3; // **
Blockly.Python.ORDER_UNARY_SIGN = 4; // + -
Blockly.Python.ORDER_BITWISE_NOT = 4; // ~
Blockly.Python.ORDER_MULTIPLICATIVE = 5; // * / // %
Blockly.Python.ORDER_ADDITIVE = 6; // + -
Blockly.Python.ORDER_BITWISE_SHIFT = 7; // << >>
Blockly.Python.ORDER_BITWISE_AND = 8; // &
Blockly.Python.ORDER_BITWISE_XOR = 9; // ^
Blockly.Python.ORDER_BITWISE_OR = 10; // |
Blockly.Python.ORDER_RELATIONAL = 11; // in, not in, is, is not,
// <, <=, >, >=, <>, !=, ==
Blockly.Python.ORDER_LOGICAL_NOT = 12; // not
Blockly.Python.ORDER_LOGICAL_AND = 13; // and
Blockly.Python.ORDER_LOGICAL_OR = 14; // or
Blockly.Python.ORDER_CONDITIONAL = 15; // if else
Blockly.Python.ORDER_LAMBDA = 16; // lambda
Blockly.Python.ORDER_NONE = 99; // (...)
/**
* Initialise the database of variable names.
*/
Blockly.Python.init = function() {
// Create a dictionary of definitions to be printed before the code.
Blockly.Python.definitions_ = Object.create(null);
// Create a dictionary mapping desired function names in definitions_
// to actual function names (to avoid collisions with user functions).
Blockly.Python.functionNames_ = Object.create(null);
if (Blockly.Variables) {
if (!Blockly.Python.variableDB_) {
Blockly.Python.variableDB_ =
new Blockly.Names(Blockly.Python.RESERVED_WORDS_);
} else {
Blockly.Python.variableDB_.reset();
}
var defvars = [];
var variables = Blockly.Variables.allVariables();
for (var x = 0; x < variables.length; x++) {
defvars[x] = Blockly.Python.variableDB_.getName(variables[x],
Blockly.Variables.NAME_TYPE) + ' = None';
}
Blockly.Python.definitions_['variables'] = defvars.join('\n');
}
};
/**
* Prepend the generated code with the variable definitions.
* @param {string} code Generated code.
* @return {string} Completed code.
*/
Blockly.Python.finish = function(code) {
// Convert the definitions dictionary into a list.
var imports = [];
var definitions = [];
for (var name in Blockly.Python.definitions_) {
var def = Blockly.Python.definitions_[name];
if (def.match(/^(from\s+\S+\s+)?import\s+\S+/)) {
imports.push(def);
} else {
definitions.push(def);
}
}
var 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 {string} line Line of generated code.
* @return {string} Legal line of code.
*/
Blockly.Python.scrubNakedValue = function(line) {
return line + '\n';
};
/**
* Encode a string as a properly escaped Python string, complete with quotes.
* @param {string} string Text to encode.
* @return {string} Python string.
* @private
*/
Blockly.Python.quote_ = function(string) {
// TODO: This is a quick hack. Replace with goog.string.quote
string = string.replace(/\\/g, '\\\\')
.replace(/\n/g, '\\\n')
.replace(/\%/g, '\\%')
.replace(/'/g, '\\\'');
return '\'' + string + '\'';
};
/**
* 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 {!Blockly.Block} block The current block.
* @param {string} code The Python code created for this block.
* @return {string} Python code with comments and subsequent blocks added.
* @private
*/
Blockly.Python.scrub_ = function(block, code) {
var commentCode = '';
// Only collect comments for blocks that aren't inline.
if (!block.outputConnection || !block.outputConnection.targetConnection) {
// Collect comment for this block.
var comment = block.getCommentText();
if (comment) {
commentCode += this.prefixLines(comment, '# ') + '\n';
}
// Collect comments for all value arguments.
// Don't collect comments for nested statements.
for (var x = 0; x < block.inputList.length; x++) {
if (block.inputList[x].type == Blockly.INPUT_VALUE) {
var childBlock = block.inputList[x].connection.targetBlock();
if (childBlock) {
var comment = this.allNestedComments(childBlock);
if (comment) {
commentCode += this.prefixLines(comment, '# ');
}
}
}
}
}
var nextBlock = block.nextConnection && block.nextConnection.targetBlock();
var nextCode = this.blockToCode(nextBlock);
return commentCode + code + nextCode;
};