//
// BaseMachine.cs
//
// Author:
// author: Dan Lewis (dlewis@gmx.co.uk)
// (c) 2002
// Copyright (C) 2005 Novell, Inc (http://www.novell.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;
using System.Collections;
using System.Collections.Specialized;
namespace System.Text.RegularExpressions{
abstract class BaseMachine : IMachine
{
internal delegate void MatchAppendEvaluator (Match match, StringBuilder sb);
public virtual string Replace (Regex regex, string input, string replacement, int count, int startat)
{
ReplacementEvaluator ev = new ReplacementEvaluator (regex, replacement);
if (regex.RightToLeft)
return RTLReplace (regex, input, new MatchEvaluator (ev.Evaluate), count, startat);
else
return LTRReplace (regex, input, new MatchAppendEvaluator (ev.EvaluateAppend), count, startat, ev.NeedsGroupsOrCaptures);
}
virtual public string [] Split (Regex regex, string input, int count, int startat)
{
ArrayList splits = new ArrayList ();
if (count == 0)
count = Int32.MaxValue;
int ptr = startat;
Match m = null;
while (--count > 0) {
if (m != null)
m = m.NextMatch ();
else
m = regex.Match (input, ptr);
if (!m.Success)
break;
if (regex.RightToLeft)
splits.Add (input.Substring (m.Index + m.Length, ptr - m.Index - m.Length));
else
splits.Add (input.Substring (ptr, m.Index - ptr));
int gcount = m.Groups.Count;
for (int gindex = 1; gindex < gcount; gindex++) {
Group grp = m.Groups [gindex];
if (grp.Length > 0)
splits.Add (input.Substring (grp.Index, grp.Length));
}
if (regex.RightToLeft)
ptr = m.Index;
else
ptr = m.Index + m.Length;
}
if (regex.RightToLeft && ptr >= 0)
splits.Add (input.Substring (0, ptr));
if (!regex.RightToLeft && ptr <= input.Length)
splits.Add (input.Substring (ptr));
return (string []) splits.ToArray (typeof (string));
}
virtual public Match Scan (Regex regex, string text, int start, int end)
{
throw new NotImplementedException ("Scan method must be implemented in derived classes");
}
virtual public string Result (string replacement, Match match)
{
return ReplacementEvaluator.Evaluate (replacement, match);
}
internal string LTRReplace (Regex regex, string input, MatchAppendEvaluator evaluator, int count, int startat) {
return LTRReplace (regex, input, evaluator, count, startat, true);
}
internal string LTRReplace (Regex regex, string input, MatchAppendEvaluator evaluator, int count, int startat, bool needs_groups_or_captures)
{
this.needs_groups_or_captures = needs_groups_or_captures;
Match m = Scan (regex, input, startat, input.Length);
if (!m.Success)
return input;
StringBuilder result = new StringBuilder (input.Length);
int ptr = startat;
int counter = count;
result.Append (input, 0, ptr);
do {
if (count != -1)
if (counter-- <= 0)
break;
if (m.Index < ptr)
throw new SystemException ("how");
result.Append (input, ptr, m.Index - ptr);
evaluator (m, result);
ptr = m.Index + m.Length;
m = m.NextMatch ();
} while (m.Success);
result.Append (input, ptr, input.Length - ptr);
return result.ToString ();
}
internal string RTLReplace (Regex regex, string input, MatchEvaluator evaluator, int count, int startat)
{
Match m = Scan (regex, input, startat, input.Length);
if (!m.Success)
return input;
int ptr = startat;
int counter = count;
#if NET_2_1
var pieces = new System.Collections.Generic.List<string> ();
#else
StringCollection pieces = new StringCollection ();
#endif
pieces.Add (input.Substring (ptr));
do {
if (count != -1)
if (counter-- <= 0)
break;
if (m.Index + m.Length > ptr)
throw new SystemException ("how");
pieces.Add (input.Substring (m.Index + m.Length, ptr - m.Index - m.Length));
pieces.Add (evaluator (m));
ptr = m.Index;
m = m.NextMatch ();
} while (m.Success);
StringBuilder result = new StringBuilder ();
result.Append (input, 0, ptr);
for (int i = pieces.Count; i > 0; )
result.Append (pieces [--i]);
pieces.Clear ();
return result.ToString ();
}
// Specify whenever Match objects created by this machine need to be fully
// built. If false, these can be omitted, avoiding some memory allocations and
// processing time.
protected bool needs_groups_or_captures = true;
}
}
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