[antlr-interest] How to write this lexer rule?
chain one
chainone at gmail.com
Tue Jan 13 18:54:01 PST 2009
I know where the problem isThere is another rule named IDENT:
IDENT
: ('a'..'z'|'A'..'Z'|'_') ('a'..'z'|'A'..'Z'|'_'|'0'..'9')*
;
seems this rule conflicts with the FUNCTION_DECL rule.
On Wed, Jan 14, 2009 at 10:09 AM, chain one <chainone at gmail.com> wrote:
> Seems it still doesn't work.I am still working on this.
> I learned a lot from your rely. Thanks Gavin.
>
> On Wed, Jan 14, 2009 at 4:21 AM, Gavin Lambert <antlr at mirality.co.nz>wrote:
>
>> At 00:29 14/01/2009, chain one wrote:
>>
>>> I tried the lexer rule you gave me. But following error comes out:
>>>
>>> Alternative 155: after matching input such as
>>> 'F''U''N''C''T''I''O''N''F''U''N''C''T''I''O''N''F''U''N''C''T''I''O''N''E''N''D''_''F''U''N''C''T''I''O''N'{'0'..'9',
>>> 'A'..'Z', '_',
>>> 'a'..'z'}'F''U''N''C''T''I''O''N''E''N''D''_''F''U''N''C''T''I''O''N'{'0'..'9',
>>> 'A'..'Z', '_', 'a'..'z'}'F''U''N''C''T''I''O'{'\u0000'..'/', ':'..'@', 'N',
>>> '['..'^', '`', '{'..'\uFFFF'} decision cannot predict what comes next due to
>>> recursion overflow to FUNCTION_DECL from FUNCTION_DECL
>>>
>>
>> Hmm. Well, another variation (that it might like better) would be:
>>
>> FUNCTION_DECL
>> : 'FUNCTION' { $channel = HIDDEN; }
>> (FUNCTION_DECL | ~'E' | 'E' (~'N' | 'N' (~'D' | 'D'
>> (~'_' | '_' (~'F' | 'F' (~'U' | 'U' (~'N' | 'N'
>> (~'C' | 'C' (~'T' | 'T' (~'I' | 'I' (~'O' | 'O'
>> (~'N' | 'N' ~SEMI))))))))))))*
>> 'END_FUNCTION' SEMI
>> ;
>>
>> Another thing that might help is to change the embedded reference to
>> FUNCTION_DECL to ('FUNCTION') => FUNCTION_DECL; ie:
>>
>> FUNCTION_DECL
>> : 'FUNCTION' { $channel = HIDDEN; }
>> ('FUNCTION') => FUNCTION_DECL | ~'E' | 'E' (~'N' | 'N'
>> (~'D' | 'D' (~'_' | '_' (~'F' | 'F' (~'U' | 'U'
>> (~'N' | 'N' (~'C' | 'C' (~'T' | 'T' (~'I' | 'I'
>> (~'O' | 'O' (~'N' | 'N' ~SEMI))))))))))))*
>> 'END_FUNCTION' SEMI
>> ;
>>
>>
>
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