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/**
* @license
* Visual Blocks Editor
*
* Copyright 2012 Google Inc.
* https://developers.google.com/blockly/
*
* 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 Utility functions for handling variables and procedure names.
* @author fraser@google.com (Neil Fraser)
*/
'use strict';
goog.provide('Blockly.Names');
/**
* Class for a database of entity names (variables, functions, etc).
* @param {string} reservedWords A comma-separated string of words that are
* illegal for use as names in a language (e.g. 'new,if,this,...').
* @param {string=} opt_variablePrefix Some languages need a '$' or a namespace
* before all variable names.
* @constructor
*/
Blockly.Names = function(reservedWords, opt_variablePrefix) {
this.variablePrefix_ = opt_variablePrefix || '';
this.reservedDict_ = Object.create(null);
if (reservedWords) {
var splitWords = reservedWords.split(',');
for (var i = 0; i < splitWords.length; i++) {
this.reservedDict_[splitWords[i]] = true;
}
}
this.reset();
};
/**
* When JavaScript (or most other languages) is generated, variable 'foo' and
* procedure 'foo' would collide. However, Blockly has no such problems since
* variable get 'foo' and procedure call 'foo' are unambiguous.
* Therefore, Blockly keeps a separate type name to disambiguate.
* getName('foo', 'variable') -> 'foo'
* getName('foo', 'procedure') -> 'foo2'
*/
/**
* Empty the database and start from scratch. The reserved words are kept.
*/
Blockly.Names.prototype.reset = function() {
this.db_ = Object.create(null);
this.dbReverse_ = Object.create(null);
};
/**
* Convert a Blockly entity name to a legal exportable entity name.
* @param {string} name The Blockly entity name (no constraints).
* @param {string} type The type of entity in Blockly
* ('VARIABLE', 'PROCEDURE', 'BUILTIN', etc...).
* @return {string} An entity name legal for the exported language.
*/
Blockly.Names.prototype.getName = function(name, type) {
var normalized = name.toLowerCase() + '_' + type;
var prefix = (type == Blockly.Variables.NAME_TYPE) ?
this.variablePrefix_ : '';
if (normalized in this.db_) {
return prefix + this.db_[normalized];
}
var safeName = this.getDistinctName(name, type);
this.db_[normalized] = safeName.substr(prefix.length);
return safeName;
};
/**
* Convert a Blockly entity name to a legal exportable entity name.
* Ensure that this is a new name not overlapping any previously defined name.
* Also check against list of reserved words for the current language and
* ensure name doesn't collide.
* @param {string} name The Blockly entity name (no constraints).
* @param {string} type The type of entity in Blockly
* ('VARIABLE', 'PROCEDURE', 'BUILTIN', etc...).
* @return {string} An entity name legal for the exported language.
*/
Blockly.Names.prototype.getDistinctName = function(name, type) {
var safeName = this.safeName_(name);
var i = '';
while (this.dbReverse_[safeName + i] ||
(safeName + i) in this.reservedDict_) {
// Collision with existing name. Create a unique name.
i = i ? i + 1 : 2;
}
safeName += i;
this.dbReverse_[safeName] = true;
var prefix = (type == Blockly.Variables.NAME_TYPE) ?
this.variablePrefix_ : '';
return prefix + safeName;
};
/**
* Given a proposed entity name, generate a name that conforms to the
* [_A-Za-z][_A-Za-z0-9]* format that most languages consider legal for
* variables.
* @param {string} name Potentially illegal entity name.
* @return {string} Safe entity name.
* @private
*/
Blockly.Names.prototype.safeName_ = function(name) {
if (!name) {
name = 'unnamed';
} else {
// Unfortunately names in non-latin characters will look like
// _E9_9F_B3_E4_B9_90 which is pretty meaningless.
name = encodeURI(name.replace(/ /g, '_')).replace(/[^\w]/g, '_');
// Most languages don't allow names with leading numbers.
if ('0123456789'.indexOf(name[0]) != -1) {
name = 'my_' + name;
}
}
return name;
};
/**
* Do the given two entity names refer to the same entity?
* Blockly names are case-insensitive.
* @param {string} name1 First name.
* @param {string} name2 Second name.
* @return {boolean} True if names are the same.
*/
Blockly.Names.equals = function(name1, name2) {
return name1.toLowerCase() == name2.toLowerCase();
};
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