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//
// InvertIfAndSimplify.cs
//
// Author:
// Ciprian Khlud <ciprian.mustiata@yahoo.com>
//
// Copyright (c) 2013 Ciprian Khlud <ciprian.mustiata@yahoo.com>
//
// 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.Collections.Generic;
using System.Linq;
namespace ICSharpCode.NRefactory.CSharp.Refactoring
{
[ContextAction("Invert If and Simplify", Description = "Inverts if and simplify branching")]
public class InvertIfAndSimplify : ICodeActionProvider
{
readonly InsertParenthesesVisitor _insertParenthesesVisitor = new InsertParenthesesVisitor();
public IEnumerable<CodeAction> GetActions(RefactoringContext context)
{
// if (condition) {CodeBlock();}else { return|break|continue;}
// will be reduced to:
//if (!condition) return|break|continue;
//CodeBlock();
var ifStatement = GetIfElseStatement(context);
if (ifStatement == null)
yield break;
yield return new CodeAction(context.TranslateString("Simplify if in loops"), script => GenerateNewScript(
script, ifStatement), ifStatement);
}
static Statement GenerateNewTrueStatement(Statement falseStatement)
{
var blockStatement = falseStatement as BlockStatement;
if (blockStatement != null) {
if (blockStatement.Children.Count(n => n.Role != Roles.NewLine && n.Role != Roles.LBrace && n.Role != Roles.RBrace) == 1)
return blockStatement.Statements.First().Clone ();
}
return falseStatement.Clone();
}
void GenerateNewScript(Script script, IfElseStatement ifStatement)
{
var mergedIfStatement = new IfElseStatement
{
Condition = CSharpUtil.InvertCondition(ifStatement.Condition)
};
var falseStatement = ifStatement.FalseStatement;
mergedIfStatement.TrueStatement = GenerateNewTrueStatement(falseStatement);
mergedIfStatement.Condition.AcceptVisitor(_insertParenthesesVisitor);
script.Replace(ifStatement, mergedIfStatement);
SimplifyIfFlowAction.InsertBody(script, ifStatement);
}
static IfElseStatement GetIfElseStatement(RefactoringContext context)
{
var result = context.GetNode<IfElseStatement>();
if (result == null || !result.IfToken.Contains(context.Location))
return null;
var falseStatement = result.FalseStatement;
var isQuitingStatement = falseStatement;
var blockStatement = falseStatement as BlockStatement;
if (blockStatement != null)
isQuitingStatement = blockStatement.Statements.FirstOrDefault();
if (isQuitingStatement is ReturnStatement || isQuitingStatement is ContinueStatement || isQuitingStatement is BreakStatement)
return result;
return null;
}
}
}
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