Re: Matlab grammar wanted.

jwe@bevo.che.wisc.edu (John W. Eaton)
9 Jan 1997 21:49:17 -0500

          From comp.compilers

Related articles
Matlab grammar wanted. jaystar@exo.com (J. E. Valstar) (1997-01-07)
Re: Matlab grammar wanted. jwe@bevo.che.wisc.edu (1997-01-09)
| List of all articles for this month |

From: jwe@bevo.che.wisc.edu (John W. Eaton)
Newsgroups: comp.compilers
Date: 9 Jan 1997 21:49:17 -0500
Organization: UW-Madison Department of Chemical Engineering
References: 97-01-047
Keywords: parse, comment

J. E. Valstar <jaystar@exo.com> wrote:


: Does anyone have, or know of, a Matlab or comparable grammar for a
: compiler generator such as PCCTS, yacc, or bison. TIA


Of the freely available systems for doing matrix math, Octave is
probably the closest to Matlab syntax. The parser is written for
bison, but I think it will also work with byacc. Octave is
distributed under the terms of the GPL and is available from
ftp.che.wisc.edu in the directory /pub/octave.


: [I wrote one on a consulting job a few years ago. The syntax is
: pretty simple so it wasn't very hard. I can't give it away, belongs
: to the people who I wrote it for. -John]


I found that it wasn't so trivial to be compatible with Matlab. For
example, given x = [ 1, 2 ], each of the following produce different
results:


    [ x (1) -2 ] == [ x, 1, -2 ] ==> [ 1 2 1 -2 ]
    [ x (1) - 2 ] == [ x, (1-2) ] ==> [ 1 2 -1 ]
    [ x(1) -2 ] == [ x(1), -2 ] ==> [ 1 -2 ]
    [ x(1) - 2 ] == [ (x(1)-2) ] ==> -1


But then again, maybe I still haven't seen the light...


--
Octave: http://www.che.wisc.edu/octave
Me: http://www.che.wisc.edu/~jwe
[I didn't say it was trivial, just not terribly hard. As I recall, we
had some kludges for those situations that returned white space as
tokens and then used rules in the parser to do the right thing. -John]
--


Post a followup to this message

Return to the comp.compilers page.
Search the comp.compilers archives again.