bool CheckBalancedGroup(RegexBuffer buffer)
{
// look for ?<Name1-Name2> or ?'Name1-Name2' syntax...
// look for ?<Name> or ?'Name' syntax...
Regex regex = new Regex(@"
^ # anchor to start of string
\?[\<|'] # ?< or ?'
(?<Name1>[a-zA-Z]+?) # Capture name1
-
(?<Name2>[a-zA-Z]+?) # Capture name2
[\>|'] # ?> or ?'
(?<Rest>.+) # The rest of the expression
" ,
RegexOptions.IgnorePatternWhitespace);
Match match = regex.Match(buffer.String);
if (match.Success)
{
description = String.Format("Balancing Group <{0}>-<{1}>", match.Groups["Name1"], match.Groups["Name2"]);
buffer.Offset += match.Groups["Rest"].Index;
expression = new RegexExpression(buffer);
CheckClosingParen(buffer);
return(true);
}
return(false);
}
bool CheckNamed(RegexBuffer buffer)
{
Regex regex;
Match match;
// look for ?<Name> or ?'Name' syntax...
regex = new Regex(@"
^ # anchor to start of string
\?(\<|') # ?< or ?'
(?<Name>[a-zA-Z0-9]+?) # Capture name
(\>|') # ?> or ?'
(?<Rest>.+) # The rest of the string
" ,
RegexOptions.IgnorePatternWhitespace);
match = regex.Match(buffer.String);
if (match.Success)
{
description = String.Format("Capture to <{0}>", match.Groups["Name"]);
// advance buffer to the rest of the expression
buffer.Offset += match.Groups["Rest"].Index;
expression = new RegexExpression(buffer);
CheckClosingParen(buffer);
return(true);
}
return(false);
}
bool HandlePlainOldCapture(RegexBuffer buffer)
{
// we're already at the expression. Just create a new
// expression, and make sure that we're at a ")" when
// we're done
if (buffer.ExplicitCapture)
{
description = String.Format("Non-capturing Group");
}
expression = new RegexExpression(buffer);
CheckClosingParen(buffer);
return(true);
}
bool CheckLookahead(RegexBuffer buffer)
{
Regex regex = new Regex(@"
^ # anchor to start of string
\?
(?<Assertion><=|<!|=|!) # assertion char
(?<Rest>.+) # The rest of the expression
" ,
RegexOptions.IgnorePatternWhitespace);
Match match = regex.Match(buffer.String);
if (match.Success)
{
switch (match.Groups["Assertion"].Value)
{
case "=":
description = "zero-width positive lookahead";
break;
case "!":
description = "zero-width negative lookahead";
break;
case "<=":
description = "zero-width positive lookbehind";
break;
case "<!":
description = "zero-width negative lookbehind";
break;
}
buffer.Offset += match.Groups["Rest"].Index;
expression = new RegexExpression(buffer);
CheckClosingParen(buffer);
return(true);
}
return(false);
}
bool CheckOptions(RegexBuffer buffer)
{
// look for ?imnsx-imnsx:
Regex regex = new Regex(@"
^ # anchor to start of string
\?(?<Options>[imnsx-]+):
" ,
RegexOptions.IgnorePatternWhitespace);
Match match = regex.Match(buffer.String);
if (match.Success)
{
string option = match.Groups["Options"].Value;
description = String.Format("Set options to {0}",
optionNames[option]);
expression = null;
buffer.Offset += match.Groups[0].Length;
return(true);
}
return(false);
}
bool CheckNonBacktracking(RegexBuffer buffer)
{
// Look for non-backtracking sub-expression ?>
Regex regex = new Regex(@"
^ # anchor to start of string
\?\>
(?<Rest>.+) # The rest of the expression
" ,
RegexOptions.IgnorePatternWhitespace);
Match match = regex.Match(buffer.String);
if (match.Success)
{
description = String.Format("Non-backtracking subexpression");
buffer.Offset += match.Groups["Rest"].Index;
expression = new RegexExpression(buffer);
this.CheckClosingParen(buffer);
return(true);
}
return(false);
}
