[antlr-interest] TokenStreamRewriteEngine: possible to use non-terminals instead of tokens?

[Terence Parr]

On Feb 4, 2004, at 6:52 AM, SainTiss wrote:
> Using the java.g grammar, what I would like to do now is delete the 
> type
> specifier from a declaration statement:
> "int myInt = 7;" => "myInt = 7;"
>
> This should only be done when the declaration is a statement, and not 
> when it
> is a class field for example...
> So it should only apply for the rule:
> statement
>     :    (declaration)=> declaration SEMI!
>
> However, it seems that the rewriteEngine can only delete a range of 
> tokens.
> SEMI is a token, but "declaration" is not so it seems (I guess its 
> type is
> "void" since that's the return type of the declaration() method?). 
> Still, I
> can't put the replace action where the type token is, because that's 
> in the
> "identifier" rule, which would mean all identifiers would be deleted...
>
> So is there a way I can "navigate" from "declaration" to the typeSpec 
> and then
> to the identifier token in order to remove it?

You need context info to trickle into typeSpec so that it knows when to 
remove that token.  you can pass a parameter around or set a context 
instance variable (ick).  Or, go the other way: just set an index in 
typeSpec as to the index of the ID token.  Then later if you ever want 
to delete it, you know the index.

Ter
--
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