LookAhead question - SyntaxEditor for Windows Forms Forum

Posted 20 years ago by (Anonymous)

I'd like to distinguish between functions and identifiers. I'm using the following regular expressions in my language definition file:


&lt;!-- Function --&gt;
&lt;RegexPatternGroup Token="FunctionToken" PatternValue="(_ | {AlphaMacro})({WordMacro})*" LookAhead="{WhitespaceMacro}*[(]"/&gt;
&lt;!-- Identifier --&gt;
&lt;RegexPatternGroup Token="IdentifierToken" PatternValue="(_ | {AlphaMacro})({WordMacro})*"/&gt;

The above definitions don't work when the last OR only text in the editor is a word. For example, if all that is in the editor is "customerID" (w/out the quotes), the token is FunctionToken. I was expecting it to be the IdentifierToken.

Why does the LookAhead for the FunctionToken match in this case?

Comments (1)

Posted 20 years ago by Actipro Software Support - Cleveland, OH, USA

Look-aheads always match at the end of the document. Try this... instead of using the LookAhead attribute, put the look-ahead inline with the pattern. Maybe try something like this which will probably not match at the end of document although you're telling it to match the same thing:


(_ | {AlphaMacro})({WordMacro})* (?={WhitespaceMacro}*[(])

Actipro Software Support

The latest build of this product (v24.1.1) was released 5 months ago, which was after the last post in this thread.

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