source: EcnlProtoTool/trunk/webapp/webmrbc/Names.cs@ 270

/**
* @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)
*/
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using Bridge;
using Bridge.Text.RegularExpressions;

namespace WebMrbc
{
        [ComVisible(true)]
        public class Names
        {
                string variablePrefix_;
                Dictionary<string, bool> reservedDict_;
                Dictionary<string, string> db_;
                Dictionary<string, bool> dbReverse_;

                /// <summary>
                /// Class for a database of entity names (variables, functions, etc).
                /// </summary>
                /// <param name="reservedWords">A comma-separated string of words that are
                /// illegal for use as names in a language (e.g. 'new,if,this,...').</param>
                /// <param name="opt_variablePrefix">Some languages need a '$' or a namespace
                /// before all variable names.</param>
                public Names(string reservedWords, string opt_variablePrefix = null)
                {
                        this.variablePrefix_ = opt_variablePrefix == null ? "" : opt_variablePrefix;
                        this.reservedDict_ = new Dictionary<string, bool>();
                        if (reservedWords != null) {
                                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'
                 */

                /// <summary>
                /// Empty the database and start from scratch.  The reserved words are kept.
                /// </summary>
                public void reset()
                {
                        this.db_ = new Dictionary<string, string>();
                        this.dbReverse_ = new Dictionary<string, bool>();
                }

                /// <summary>
                /// Convert a Blockly entity name to a legal exportable entity name.
                /// </summary>
                /// <param name="name">The Blockly entity name (no constraints).</param>
                /// <param name="type">The type of entity in Blockly
                /// ('VARIABLE', 'PROCEDURE', 'BUILTIN', etc...).</param>
                /// <returns>An entity name legal for the exported language.</returns>
                public string getName(string name, string type)
                {
                        var normalized = name.ToLower() + '_' + type;
                        var prefix = (type == Blockly.Variables.NAME_TYPE) ?
                                this.variablePrefix_ : "";
                        if (this.db_.ContainsKey(normalized)) {
                                return prefix + this.db_[normalized];
                        }
                        var safeName = this.getDistinctName(name, type);
                        this.db_[normalized] = safeName.Substr(prefix.Length);
                        return safeName;
                }

                /// <summary>
                /// 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.
                /// </summary>
                /// <param name="name">The Blockly entity name (no constraints).</param>
                /// <param name="type">The type of entity in Blockly
                /// ('VARIABLE', 'PROCEDURE', 'BUILTIN', etc...).</param>
                /// <returns>An entity name legal for the exported language.</returns>
                public string getDistinctName(string name, string type)
                {
                        var safeName = this.safeName_(name);
                        var i = 0;
                        while (this.dbReverse_.ContainsKey(safeName + ((i == 0) ? "" : i.ToString())) ||
                                   this.reservedDict_.ContainsKey(safeName + i.ToString())) {
                                // Collision with existing name.  Create a unique name.
                                i++;
                        }
                        if (i > 0)
                                safeName += i;
                        this.dbReverse_[safeName] = true;
                        var prefix = (type == Blockly.Variables.NAME_TYPE) ?
                                this.variablePrefix_ : "";
                        return prefix + safeName;
                }

                /// <summary>
                /// 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.
                /// </summary>
                /// <param name="name">Potentially illegal entity name.</param>
                /// <returns>Safe entity name.</returns>
                public string safeName_(string name)
                {
                        if (name == null) {
                                name = "unnamed";
                        }
                        else {
                                // Unfortunately names in non-latin characters will look like
                                // _E9_9F_B3_E4_B9_90 which is pretty meaningless.
                                name = Script.EncodeURI(name.Replace(new Regex(" "), "_").Replace(new Regex(@"[^\w]"), "_"));
                                // Most languages don't allow names with leading numbers.
                                if ("0123456789".IndexOf(name[0]) != -1) {
                                        name = "my_" + name;
                                }
                        }
                        return name;
                }

                /// <summary>
                /// Do the given two entity names refer to the same entity?
                /// Blockly names are case-insensitive.
                /// </summary>
                /// <param name="name1">First name.</param>
                /// <param name="name2">Second name.</param>
                /// <returns>True if names are the same.</returns>
                public bool equals(string name1, string name2)
                {
                        return name1.ToLower() == name2.ToLower();
                }
        }
}