[antlr-interest] meaning of #xxx

[Kevin J. Cummings]

On 05/12/2011 10:51 AM, Philippe Frankson wrote:
> Hi,
> In a grammar done with ANTLR 2.x, I have seen the following expression:
> 
> sql_literal:
>         ( NUMBER | QUOTED_STRING | "null" )
>         { #sql_literal = #([SQL_LITERAL, "sql_literal"], #sql_literal);
> }
>     ;
> 
> Anybody can explain the meaning of the code inside the  { } ? (or send a
> link where I can find the doc).

You should read the documentation.  Its all explained in the "ANTLR
Reference Manual".

{} surround action blocks.  Code from the target language that should be
executed after the previous rule (or sub-rule) was matched.

> #sql_literal ?

#ruleName is the resulting AST tree.  In this case, for the rule being
executed.  In this case, it sets the AST for this rule to what's on the RHS.

> #(x,y) ?

This is AST construction.  What's in the []'s is a token creation of the
form [TOKEN_TYPE, token_spelling]

> I could not find relevant documentation explaining that.

Start here:

http://www.antlr2.org/doc/index.html

There is lots of documentation on the ANTLR V2 site....

> Thx a lot.
> Philippe

-- 
Kevin J. Cummings
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cummings at kjchome.homeip.net
cummings at kjc386.framingham.ma.us
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