[antlr-interest] Tweaking a source file.

[Terence Parr]

On Oct 17, 2006, at 8:32 PM, David Piepgrass wrote:
> The first decision I need to make is, should I use ANTLR 2 or ANTLR  
> 3? The readme for ANTLR 3 says "For example, to read in some input,  
> tweak it, and write it back out preserving whitespace, is easy in  
> v3." That sounds great because it is exactly what I need to  
> accomplish.  But how can it be done?

Use TokenRewriteStream instead of COmmonTokenStream.  Look at the v2  
to v3 translator I just did for an example. :)

ter

> Does an example exist? For my application, I think an observer  
> inserted between the lexer and parser can do the job--I just don't  
> know the details.
>
> The second big question is, what is the easiest way to make an AST,  
> and is this task also easier in v3?
>
> The third question is, how can one parse a language where  
> indentation is syntactically significant?
>

Keep whitespace tokens as real tokens (don't skip them). :)

Ter