[antlr-interest] Building syntax highlighters with ANTLR

[Sam Harwell]

It looks like we are working towards two very different goals. I'm not
trying to do any parsing, block structure analysis, pair matching, etc.
I'm just trying to color comments, identifiers, keywords, etc with
individual colors.

 

Sam

 

From: antlr-interest-bounces at antlr.org
[mailto:antlr-interest-bounces at antlr.org] On Behalf Of Gerald Rosenberg
Sent: Wednesday, April 15, 2009 11:29 PM
To: antlr-interest at antlr.org
Subject: Re: [antlr-interest] Building syntax highlighters with ANTLR

 

A better approach is to use a predicate.  That way you don't have to
intercept every lexer token and makes it considerably easier to handle
multiple pair sets.  

@lexer ::members {
  public boolean pairMatch(int limit) {
    return PairMatcherHelper.pairMatch(input, limit);
  }
  public boolean pairMatch(int limit, char beg, char end) {
    return PairMatcherHelper.pairMatch(input, limit, beg, end);
  }
}

BRACE_BLOCK :'{' { pairMatch(200) }? ;
BRACKET_BLOCK :'[' { pairMatch(50, '[', ']') }? ;

PairMatcherHelper#pairMatch then does full nested pair matching, subject
to certain limitations.  Does respect Antlr's backtracking semantics.

Note, the attached version is set up for just for single char
delimiters.




At 10:56 AM 4/15/2009, Sam Harwell wrote:




The new method uses a very different override of NextToken(). The outer
loop is largely a duplication of the functionality of Lexer.NextToken().
I've highlighted the key section that reliably manages the lexer state
information (yay HTML email).
 
public override IToken NextToken()
{
    for ( ; ; )

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.antlr.org/pipermail/antlr-interest/attachments/20090416/8c102709/attachment.html