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private RegexFCFromRegexTree ( |
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| tree | ||
| return | ||
/*
* This is the one of the only two functions that should be called from outside.
* It takes a RegexTree and computes the set of chars that can start it.
*/
internal static RegexPrefix FirstChars(RegexTree t) {
RegexFCD s = new RegexFCD();
RegexFC fc = s.RegexFCFromRegexTree(t);
if (fc == null || fc._nullable)
return null;
CultureInfo culture = ((t._options & RegexOptions.CultureInvariant) != 0) ? CultureInfo.InvariantCulture : CultureInfo.CurrentCulture;
return new RegexPrefix(fc.GetFirstChars(culture), fc.IsCaseInsensitive());
}
/*
* This is the one of the only two functions that should be called from outside.
* It takes a RegexTree and computes the set of chars that can start it.
*/
internal static RegexPrefix FirstChars(RegexTree t)
{
RegexFCD s = new RegexFCD();
RegexFC fc = s.RegexFCFromRegexTree(t);
if (fc == null || fc._nullable)
{
return(null);
}
CultureInfo culture = ((t._options & RegexOptions.CultureInvariant) != 0) ? CultureInfo.InvariantCulture : CultureInfo.CurrentCulture;
return(new RegexPrefix(fc.GetFirstChars(culture), fc.IsCaseInsensitive()));
}
/// <summary>
/// This is the one of the only two functions that should be called from outside.
/// It takes a RegexTree and computes the set of chars that can start it.
/// </summary>
public static RegexPrefix?FirstChars(RegexTree t)
{
// Create/rent buffers
Span <int> intSpan = stackalloc int[StackBufferSize];
RegexFCD s = new RegexFCD(intSpan);
RegexFC fc = s.RegexFCFromRegexTree(t);
s.Dispose();
if (fc == null || fc._nullable)
{
return(null);
}
CultureInfo culture = ((t.Options & RegexOptions.CultureInvariant) != 0) ? CultureInfo.InvariantCulture : CultureInfo.CurrentCulture;
return(new RegexPrefix(fc.GetFirstChars(culture), fc.CaseInsensitive));
}