From: Taco Hoekwater <taco@elvenkind.com>
To: mailing list for ConTeXt users <ntg-context@ntg.nl>
Subject: Re: Off-topic: Struggles with LPEG grammar
Date: Mon, 21 Dec 2020 13:46:45 +0100 [thread overview]
Message-ID: <364BD99F-0BC4-4CAB-84AD-AED668455854@elvenkind.com> (raw)
In-Reply-To: <CALBOmsbPGuSSRnmBkmEbnw9WYcYJAUkR-0rK99fK9YP3RsUN7A@mail.gmail.com>
> On 21 Dec 2020, at 13:16, Mojca Miklavec <mojca.miklavec.lists@gmail.com> wrote:
>
> My only explanation would be that perhaps "^1" is so greedy that the
> rest of the pattern doesn't get found. But I don't want to believe
> that explanation.
Which (of course) means that that is exactly what happens ;)
The ones that match are
ababbb (a (ba+bb) b) => r4 r1(r3(r5 r4) r2(r5 r5)) r5
abbbab (a (bb+ba) b) => r4 r1(r2(r5 r5) r3(r5 r4)) r5
With the ^1, in the “bb” cases the first “b” eats all three “b”s:
ababbb fails the r5 at the end
abbbab fails the first r2 already (since the second r5 therein never happens)
Best wishes,
Taco
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next prev parent reply other threads:[~2020-12-21 12:46 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-21 12:16 Mojca Miklavec
2020-12-21 12:46 ` Taco Hoekwater [this message]
2020-12-21 12:50 ` Taco Hoekwater
2020-12-21 13:08 ` Mojca Miklavec
2020-12-21 13:36 ` Taco Hoekwater
2020-12-21 13:47 ` luigi scarso
2020-12-21 14:10 ` Mojca Miklavec
2020-12-21 14:18 ` Taco Hoekwater
2020-12-21 14:44 ` Hans Hagen
2020-12-21 13:38 ` Arthur Reutenauer
2020-12-21 13:52 ` Hans Hagen
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