Re: .. can never be matched as ..

Newsgroups	comp.compilers.tools.javacc
Date	2013-06-26 01:54 -0700
References	<a97fb75d-65e6-404e-be08-d1b4c83ece54@googlegroups.com>
Message-ID	<4a67f7ed-9ec9-4986-b65f-c339376a04f0@googlegroups.com> (permalink)
Subject	Re: .. can never be matched as ..
From	bbllatwork@gmail.com

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Considering the order of token definitions, the token TERM will never match anything, because it was already matched by the CONSTANT/VARIABLE definitions itself.

If you want to use tokens only within other tokens, use the following definition:

<#MY_TOKEN_PART: "bla">
<MY_TOKEN: <MY_TOKEN_PART> "blu">

Hope that helps.

> On Saturday, May 18, 2013 12:25:36 AM UTC+8, Walter Milner wrote:
> My grammar includes:
> 
> TOKEN : { < CONSTANT : (["0"-"9"])+ > }
> 
> TOKEN : { < VARIABLE : ["x"-"z"] > }
> 
> TOKEN : { < TERM :   <CONSTANT> | <VARIABLE>  > }
> 
> but I get warning Regular expression choice : CONSTANT can never be matched as : TERM
> 
> Why not?
> 
> How come
> 
> 12
> 
> would not be a term, since it is a constant?
> 
> Aplogies for my lack of a brain

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.. can never be matched as .. Walter Milner <w.w.milner@googlemail.com> - 2013-05-17 09:25 -0700
  Re: .. can never be matched as .. bbllatwork@gmail.com - 2013-06-26 01:54 -0700

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