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Re: Grammar doesn't seem to match any token

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From:
yary
Date:
September 24, 2018 00:02
Subject:
Re: Grammar doesn't seem to match any token
Message ID:
CAG2CFAb+HoR4SAm_OPVMEnyUt6Ubxck5QwOMxrRqcTo1xBL_Dg@mail.gmail.com
Let's see.

If you have my $input = '~i o<<<', then <other> matches.

 'rule' turns on :sigspace. If you use 'token' instead of 'rule' then
<other> matches.

I don't quite have the full picture of what's happening.

-y

On Sun, Sep 23, 2018 at 7:07 PM, Mark Carter <alt.mcarter@gmail.com> wrote:

> My grammar doesn't seem to match the 'other' rule. What's wrong with it?
>
> grammar Weave {
>         token TOP {  <el> * }
>         rule el {  <lt> | <tilde> | <other>  }
>         rule lt { '<'  }
>         rule tilde { '~' \S+ }
>         rule other { .  }
> }
>
> class Weaver {
>         has Str $.outstr;
>
>         method TOP   ($/) { make $<el> ; put("top called") ; put($<el>) }
>         method el    ($/) { put($/) }
>         method tilde ($/) { say 'tilde called' }
>         method lt    ($/) { make '&lt;' ; put('&lt'); $!outstr ~= 'X' }
>         method other ($/) { $!outstr ~= '.'; say 'other called'; put('.');
> }
>
> }
>
> $input = '~i <<<YZ';
> my $w = Weaver.new();
> Weave.parse($input, :actions($w));
> say $w.outstr; # outputs XXX
>
> It never once says 'other called'. It seems to be matching the '<' signs
> OK, and I think the '~' is OK, too. It's just any other token that it's not
> matching.
>

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