// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt) // This code is distributed under MIT X11 license (for details please see \doc\license.txt) using System; using System.Collections.Generic; using System.Diagnostics; namespace ICSharpCode.NRefactory.CSharp.PatternMatching { /// /// Represents an optional node. /// public class Repeat : Pattern { public static readonly Role ElementRole = new Role("Element", AstNode.Null); public int MinCount; public int MaxCount = int.MaxValue; public Repeat(AstNode childNode) { AddChild(childNode, ElementRole); } internal override bool DoMatchCollection(Role role, AstNode pos, Match match, Stack backtrackingStack) { Debug.Assert(pos == null || pos.Role == role); int matchCount = 0; if (this.MinCount <= 0) backtrackingStack.Push(new PossibleMatch(pos, match.CheckPoint())); AstNode element = GetChildByRole(ElementRole); while (matchCount < this.MaxCount && pos != null && element.DoMatch(pos, match)) { matchCount++; do { pos = pos.NextSibling; } while (pos != null && pos.Role != role); if (matchCount >= this.MinCount) backtrackingStack.Push(new PossibleMatch(pos, match.CheckPoint())); } return false; // never do a normal (single-element) match; always make the caller look at the results on the back-tracking stack. } protected internal override bool DoMatch(AstNode other, Match match) { if (other == null || other.IsNull) return this.MinCount <= 0; else return this.MaxCount >= 1 && GetChildByRole(ElementRole).DoMatch(other, match); } public override S AcceptVisitor(IAstVisitor visitor, T data) { return ((IPatternAstVisitor)visitor).VisitRepeat(this, data); } } }