jagregory / boolangstudio forked from olsonjeffery/boolangstudio

Boo language integration for Visual Studio 2008

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cc5d8294 » jagregory 2008-09-01 Implemented brace matching.... 1 using System;
2 using System.Collections.Generic;
3
4 namespace Boo.BooLangService.StringParsing
5 {
6 public class StringWalker
7 {
8 private const char LeftParenthesis = '(';
9 private const char RightParenthesis = ')';
10 private const char DoubleQuote = '"';
11 private const char BackSlash = '\\';
12
13 private bool abort;
14 private Stack<StringWalkerState> state;
15
16 public IEnumerable<StringPosition> Iterate(string value)
17 {
18 state = new Stack<StringWalkerState>();
19
20 for (var currentIndex = 0; currentIndex < value.Length; currentIndex++)
21 {
22 if (abort) break;
23
24 var currentChar = value[currentIndex];
25
26 if (currentChar == LeftParenthesis)
27 state.Push(StringWalkerState.InsideParentheses);
28 else if (currentChar == RightParenthesis && StateIs(StringWalkerState.InsideParentheses))
29 state.Pop();
30 else if (currentChar == DoubleQuote && StateIs(StringWalkerState.InsideString))
31 state.Pop();
32 else if (currentChar == DoubleQuote)
33 state.Push(StringWalkerState.InsideString);
34 else if (currentChar == BackSlash && StateIs(StringWalkerState.InsideString))
35 currentIndex += 1; // skip next (escaped) char
36
54d4bcef » jagregory 2008-09-01 Some changes to brace match... 37 if (ShouldYield(currentChar))
38 yield return new StringPosition(currentChar, currentIndex);
cc5d8294 » jagregory 2008-09-01 Implemented brace matching.... 39 }
40 }
41
54d4bcef » jagregory 2008-09-01 Some changes to brace match... 42 protected virtual bool ShouldYield(char currentChar)
43 {
44 return true;
45 }
46
cc5d8294 » jagregory 2008-09-01 Implemented brace matching.... 47 public bool StateIs(StringWalkerState expectedState)
48 {
49 if (state.Count == 0) return false;
50
51 return state.Peek() == expectedState;
52 }
53
54 public void Abort()
55 {
56 abort = true;
57 }
58
59 public bool HasNoState
60 {
61 get { return state == null || state.Count == 0; }
62 }
63 }
64 }