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stgsharp/StgSharp.RegularAnalysis/Text/RegexAnalyzerBackEnd.CharSetEmitter.cs
T

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4.4 KiB
C#

//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="RegexAnalyzerBackEnd.CharSetEmitter"
// Project: StgSharp
// AuthorGroup: Nitload
// Copyright (c) Nitload. All rights reserved.
//
// 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.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace StgSharp.RegularAnalysis.Text
{
internal enum CharSetType
{
None,
Single,
Range,
Set
}
internal record struct RegexCharSet(
string value,
CharSetType t,
bool accept
)
{
public bool IsAcceptable { get; set; } = accept;
public CharSetType Type { get; set; } = t;
public string Value { get; set; } = value;
public override readonly string ToString()
{
return $"{{value:{value}, type:{Type}, accept:{IsAcceptable}}}";
}
}
internal static partial class RegexAnalyzerBackEnd
{
public static RegexCharSet[] FigureCharSetType(
ReadOnlySpan<char> source
)
{
// range or single
bool accept;
if (source[0] == '[')
{
int idx;
accept = source[1] != '^';
idx = accept ? 1 : 2;
ReadOnlySpan<char> seq = source.Slice(idx, source.Length - idx - 1);
if (seq.IndexOf('-') == -1)
{
return [new RegexCharSet(seq.ToString(), CharSetType.Single, accept)];
} else
{
List<RegexCharSet> list = [];
for (; seq.Length > 0; )
{
int pos = seq.IndexOf('-');
if (pos == -1)
{
RegexCharSet single = new(seq.ToString(), CharSetType.Single, accept);
list.Add(single);
break;
} else
if (pos > 1) {
list.Add(new(seq[0..(pos - 1)].ToString(), CharSetType.Single, accept));
}
list.Add(new($"{seq[pos - 1]}{seq[pos + 1]}", CharSetType.Range, accept));
seq = seq[(pos + 2)..];
}
return [.. list];
}
} else if (source[0] == '\\')
{
// set
accept = char.IsAsciiLetterUpper(source[0]);
return char.ToLower(source[0], CultureInfo.InvariantCulture)
switch
{
's' => [new("s", CharSetType.Set, accept)],
'w' => [new("w", CharSetType.Set, accept)],
'd' => [new("d", CharSetType.Set, accept)],
_ => throw new NotSupportedException()
};
} else
{
// unknown, throw
throw new InvalidCastException($"Unknown char set: {source}");
}
}
}
}