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| From | Grant Edwards <invalid@invalid.invalid> |
| Newsgroups | comp.lang.python |
| Subject | Re: Yet another attempt at a safe eval() call |
| Date | Fri, 4 Jan 2013 18:43:46 +0000 (UTC) |
| Organization | PANIX Public Access Internet and UNIX, NYC |
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On 2013-01-04, Chris Angelico <rosuav@gmail.com> wrote:
> On Sat, Jan 5, 2013 at 5:09 AM, Grant Edwards <invalid@invalid.invalid> wrote:
>> The error messages are still pretty cryptic, so improving
>> that will add a few more lines. One nice thing about the ast code is
>> that it's simple to add code to allow C-like character constants such
>> that ('A' === 0x41). Here's the first pass at ast-based code:
>
> Looks cool, and fairly neat! Now I wonder, is it possible to use that
> to create new operators, such as the letter d? Binary operator, takes
> two integers...
I don't think you can define new operators. AFAICT, the
lexing/parsing is done using the built-in Python grammar. You can
control the behavior of the predefined operators and reject operators
you don't like, but you can't add new ones or change precedence/syntax
or anything like that.
If you want to tweak the grammar itself, then I think you need to use
something like pyparsing.
--
Grant Edwards grant.b.edwards Yow! I own seven-eighths of
at all the artists in downtown
gmail.com Burbank!
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Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-03 23:25 +0000
Re: Yet another attempt at a safe eval() call Tim Chase <python.list@tim.thechases.com> - 2013-01-03 19:11 -0600
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 02:34 +0000
Re: Yet another attempt at a safe eval() call Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-04 07:47 +0000
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 15:53 +0000
Re: Yet another attempt at a safe eval() call Michael Torrie <torriem@gmail.com> - 2013-01-04 09:05 -0700
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 16:16 +0000
Re: Yet another attempt at a safe eval() call Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-01-05 15:56 +0000
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-06 15:12 +0000
Re: Yet another attempt at a safe eval() call Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-01-07 00:08 +0000
Re: Yet another attempt at a safe eval() call Chris Angelico <rosuav@gmail.com> - 2013-01-06 03:01 +1100
Re: Yet another attempt at a safe eval() call Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-01-05 16:17 +0000
Re: Yet another attempt at a safe eval() call matt.newville@gmail.com - 2013-01-05 08:40 -0800
Re: Yet another attempt at a safe eval() call matt.newville@gmail.com - 2013-01-05 08:40 -0800
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 16:38 +0000
Re: Yet another attempt at a safe eval() call Chris Angelico <rosuav@gmail.com> - 2013-01-05 03:51 +1100
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 17:14 +0000
Re: Yet another attempt at a safe eval() call Chris Angelico <rosuav@gmail.com> - 2013-01-05 04:21 +1100
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 18:09 +0000
Re: Yet another attempt at a safe eval() call Chris Angelico <rosuav@gmail.com> - 2013-01-05 05:23 +1100
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 18:43 +0000
Re: Yet another attempt at a safe eval() call Chris Angelico <rosuav@gmail.com> - 2013-01-05 06:02 +1100
Re: Yet another attempt at a safe eval() call Chris Rebert <clp2@rebertia.com> - 2013-01-03 23:50 -0800
Re: Yet another attempt at a safe eval() call Terry Reedy <tjreedy@udel.edu> - 2013-01-04 07:24 -0500
Re: Yet another attempt at a safe eval() call Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-04 13:33 +0000
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 15:59 +0000
Re: Yet another attempt at a safe eval() call Alister <alister.ware@ntlworld.com> - 2013-01-04 18:13 +0000
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