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From: Kaz Kylheku <336-986-7787@kylheku.com>
Newsgroups: comp.compilers
Subject: Re: [ANN] RE/flex 0.9.18 - a Flex-like lexical analyzer generator for C++
Date: Tue, 28 Mar 2017 17:32:21 +0000 (UTC)
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On 2017-03-28, C BergstrC6m <cbergstrom@pathscale.com> wrote:
> Cool!
>
> Is this meant as a flex drop-in replacement? iirc (we) PathScale have
> sent patches to upstream Flex before and I don't remember if they were
> responsive or not. If you are 1:1 compatible, have you tried to
> replace the system flex and rebuild world or how extensively has this
> been validated? You may find the BSD community to be interested and
> empathetic if it can help them.

A nice feature in Flex might be parametrized named regexes:

You know how we can define

  ALF [A-Z]+

and later use

  {ALF}

?

OK; now what if we could have us some params:

  FOO{X} [0-9]{X}+#

then:

  {FOO Z}     /* expands to [0-9](Z)+# */

Thumbs up? Down?



Multiple params def:

  FOO{X Y Z} ... {X} ... {Y}+{Z}

Multiple params ref:

  {FOO [^x] . {ALF}}

Cheers ...
[You could whip that up in an hour as a preprocessor to flex, you know. -John]