Sure, here you are <https://github.com/jeffreykegler/Marpa--R2/issues/75>.


On Sat, Jan 11, 2014 at 9:16 PM, Jeffrey Kegler <
[email protected]> wrote:

>  The fix is more comlex because whatever form the action descriptor takes
> must be parsed later on in the code.  Could you create an issue for this in
> the Github repository?  I am hot on the trail of other, I hope very
> promising, improvements, and I want to put this lower on the priority
> queue.  The github issue will help ensure I do not forget, and allow you
> and others to track it.
>
> -- jeffrey
>
>
> On 01/10/2014 08:04 AM, Ruslan Shvedov wrote:
>
>  On Fri, Jan 10, 2014 at 5:59 PM, Jeffrey Kegler <
> [email protected]> wrote:
>
>>  The behavior described seems tol be as documented.  "Discarding" is of
>> lexemes, and does not happen inside lexemes.  That is, the lexemes form a
>> series of tokens, some of which are discarded.  But discarding does not
>> happen "within" the lexeme.
>>
>> If you are discarding space, but also want a lexeme to contain spaces,
>> you have to arrange for that in some other way.  One is what you suggest:
>> "Change "~" to "::=".  Another is to change the separator of <result item
>> descriptor list> to include the spacing around a comma.
>>
>> This was a quick answer -- let me know if I've missed the point.
>>
> Nope, thanks, the answer is quite to the point.
>
>  What happended was I tried to write *[start, length, values]* with
> spaces in a SLIF grammar and its creation failed.
>
>  This patch to metag.bnf, per your suggestion, would allow spaces
>
>  -<array descriptor> ~ '[' <result item descriptor list> ']'
> -<result item descriptor list> ~ <result item descriptor>* separator => [,]
> +<array descriptor> ::= '[' <result item descriptor list> ']'
> +<result item descriptor list> ::= <result item descriptor>* separator =>
> [,]
>  <result item descriptor> ~ 'start' | 'length' | 'value' | 'values'
>
>   -- jeffey
>>
> ruslan
>
>
>>
>>   On 01/10/2014 07:05 AM, Ruslan Shvedov wrote:
>>
>>   String '[ start, length, values ]' can't be parsed with the grammar
>> below, as more fully described in the attached script, unless <result item
>> descriptor list> is changed to G1 rule.
>>
>>  <array descriptor> ::= '[' <result item descriptor list> ']'
>>  # the test passes (whitespaces are discarded) if the below line becomes
>> a G1 (s/~/::=/) rule
>> <result item descriptor list> ~ <result item descriptor>* separator => [,]
>> <result item descriptor> ~ 'start' | 'length' | 'value' | 'values'
>>
>>  :discard ~ whitespace
>> whitespace ~ [\s]+
>>
>>  The following exception is thrown:
>>
>>  Error in SLIF parse: No lexemes accepted at line 1, column 10
>>    Lexer "L0" rejected 1 lexeme(s)
>>   Rejected lexeme #1: <result item descriptor list>; value="length,";
>> length = 7
>> * String before error: [ start,\s
>> * The error was at line 1, column 10, and at character 0x006c 'l', ...
>> * here: length, values ]
>>
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