source: trunk/HeuristicLab.ExtLibs/HeuristicLab.NRefactory/5.5.0/NRefactory.CSharp-5.5.0/Refactoring/NamingHelper.cs @ 17197

//
// NamingHelper.cs
//
// Author:
//       Simon Lindgren <simon.n.lindgren@gmail.com>
//
// Copyright (c) 2012 Simon Lindgren
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
using System;
using System.Collections.Generic;
using System.Text;
using ICSharpCode.NRefactory.TypeSystem;
using ICSharpCode.NRefactory.Semantics;

namespace ICSharpCode.NRefactory.CSharp.Refactoring
{
  public class NamingHelper
  {
    ISet<string> usedVariableNames;
    RefactoringContext context;

    public NamingHelper(RefactoringContext context)
    {
      this.context = context;
      if (usedVariableNames == null) {
        var visitor = new VariableFinderVisitor();
        var astNode = context.GetNode<Statement>();
        astNode.AcceptVisitor(visitor);
        usedVariableNames = visitor.VariableNames;
      }
    }

    public static IEnumerable<string> GenerateNameProposals(AstType type)
    {
      if (type is PrimitiveType) {
        var pt = (PrimitiveType)type;
        switch (pt.Keyword) {
          case "object":
            yield return "o";
            yield return "obj";
            break;
          case "bool":
            yield return "b";
            yield return "pred";
            break;
          case "double":
          case "float":
          case "decimal":
            yield return "d";
            yield return "f";
            yield return "m";
            break;
          case "char":
            yield return "c";
            break;
          default:
            yield return "i";
            yield return "j";
            yield return "k";
            break;
        }
        yield break;
      }
      string name;
      if (type is SimpleType) {
        name = ((SimpleType)type).Identifier;
      } else if (type is MemberType) {
        name = ((MemberType)type).MemberName;
      } else {
        yield break;
      }

      var names = WordParser.BreakWords(name);
      if (names.Count > 0) {
        names [0] = Char.ToLower(names [0] [0]) + names [0].Substring(1);
      }
      yield return string.Join("", names);
    }

    /// <summary>
    /// Generates a variable name for a variable of the specified type.
    /// </summary>
    /// <returns>
    /// The variable name.
    /// </returns>
    /// <param name='type'>
    /// The type of the variable.
    /// </param>
    /// <param name='baseName'>
    /// Suggested base name.
    /// </param>
    public string GenerateVariableName(AstType type, string baseName = null)
    {
      if (baseName == null) {
        foreach (var name in NamingHelper.GenerateNameProposals(type)) {
          baseName = baseName ?? name;
          if (NameIsUnused(name)) {
            usedVariableNames.Add(name);
            return name;
          }
        }
      } else if (NameIsUnused(baseName)) {
        return baseName;
      }

      // If we get here, all of the standard suggestions are already used.
      // This will at least be the second variable named based on firstSuggestion, so start at 2
      int counter = 2;
      string proposedName;
      do {
        proposedName = baseName + counter++;
      } while (!NameIsUnused(proposedName));
      usedVariableNames.Add(proposedName);
      return proposedName;
    }

    bool NameIsUnused(string name)
    {
      return !usedVariableNames.Contains(name) && LookupVariable(name) == null;
    }

    /// <summary>
    /// Generates a variable name for a variable of the specified type.
    /// </summary>
    /// <returns>
    /// The variable name.
    /// </returns>
    /// <param name='type'>
    /// The type of the variable.
    /// </param>
    /// <param name='baseName'>
    /// Suggested base name.
    /// </param>
    public string GenerateVariableName(IType type, string baseName = null)
    {
      AstType astType = ToAstType(type);
      return GenerateVariableName(astType, baseName);
    }

    AstType ToAstType(IType type)
    {
      switch (type.FullName) {
        case "System.Object":
          return new PrimitiveType("object");
        case "System.String":
          return new PrimitiveType("string");
        case "System.Boolean":
          return new PrimitiveType("bool");
        case "System.Char":
          return new PrimitiveType("char");
        case "System.SByte":
          return new PrimitiveType("sbyte");
        case "System.Byte":
          return new PrimitiveType("byte");
        case "System.Int16":
          return new PrimitiveType("short");
        case "System.UInt16":
          return new PrimitiveType("ushort");
        case "System.Int32":
          return new PrimitiveType("int");
        case "System.UInt32":
          return new PrimitiveType("uint");
        case "System.Int64":
          return new PrimitiveType("long");
        case "System.UInt64":
          return new PrimitiveType("ulong");
        case "System.Single":
          return new PrimitiveType("float");
        case "System.Double":
          return new PrimitiveType("double");
        case "System.Decimal":
          return new PrimitiveType("decimal");
        default:
          return new SimpleType(type.Name);
      }
    }

    IVariable LookupVariable(string name)
    {
      var blockStatement = context.GetNode<BlockStatement>();
      var resolverState = context.GetResolverStateAfter(blockStatement.RBraceToken.PrevSibling);
      var simpleNameRR = resolverState.ResolveSimpleName(name, new List<IType>()) as LocalResolveResult;
      if (simpleNameRR == null)
        return null;
      return simpleNameRR.Variable;
    }

    class VariableFinderVisitor : DepthFirstAstVisitor
    {

      public ISet<string> VariableNames = new HashSet<string>();

      public override void VisitVariableInitializer(VariableInitializer variableInitializer)
      {
        ProcessName(variableInitializer.Name);
        base.VisitVariableInitializer(variableInitializer);
      }

      public override void VisitQueryLetClause(QueryLetClause queryLetClause)
      {
        ProcessName(queryLetClause.Identifier);
        base.VisitQueryLetClause(queryLetClause);
      }

      public override void VisitQueryFromClause(QueryFromClause queryFromClause)
      {
        ProcessName(queryFromClause.Identifier);
        base.VisitQueryFromClause(queryFromClause);
      }

      public override void VisitQueryContinuationClause(QueryContinuationClause queryContinuationClause)
      {
        ProcessName(queryContinuationClause.Identifier);
        base.VisitQueryContinuationClause(queryContinuationClause);
      }

      void ProcessName(string name)
      {
        if (!VariableNames.Contains(name))
          VariableNames.Add(name);
      }
    }
  }
}