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Groups > comp.compilers > #1303
| From | glen herrmannsfeldt <gah@ugcs.caltech.edu> |
|---|---|
| Newsgroups | comp.compilers |
| Subject | Re: Parsing Fortran, was specifying semantics |
| Date | 2014-07-04 17:53 +0000 |
| Organization | Aioe.org NNTP Server |
| Message-ID | <14-07-013@comp.compilers> (permalink) |
| References | (4 earlier) <14-06-030@comp.compilers> <14-06-031@comp.compilers> <14-07-003@comp.compilers> <14-07-006@comp.compilers> <14-07-011@comp.compilers> |
Hans-Peter Diettrich <DrDiettrich1@aol.com> wrote:
(snip)
> whitespace popped up, where whitespace sometimes is required to separate
> keywords from identifiers, sometimes is optional:
> Fortran: D O I = ...
> Pascal: if x ...
> C: int i ...
(snip)
> [You can scan Fortran with longest match, but the things you're
> matching for are very context dependent. I've done it. I agree that
> it's unlikely we'll find a general model for different languages. -John]
The two favorite ones that I always remember for Fortran are:
DO1I=1,2
and
DO 1 I=1.2
(and with no IMPLICIT NONE in effect, or with DO1I already declared).
To avoid these kinds of problems, WATFIV disallows "FORMAT(" as the
first seven characters of a statement that isn't a FORMAT statement.
Doesn't seem like it is overly restrictive, but when using variable
format, I always called my array (it had to be an array back then)
FORMAT.
-- glen
[To parse a Fortran statement you first have to decide whether it's an
assignment or something else, after which you can use a simple
contnext sensitive longest match to find the tokens. To see if it's
an assignment, you look for an = sign that is not followed by a comma
that is not inside parens, being sure to skip over 'literal' and
9hHollerith strings and noting that in typical dialects the statement
REAL*4HFOO does not contain a Hollerith string.. It wasn't as hard as
it sounds. -John]
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Formatting of Language LRMs Seima Rao <seimarao@gmail.com> - 2014-06-17 16:54 +0530
Re: Formatting of Language LRMs "lpsantil@gmail.com" <lpsantil@gmail.com> - 2014-06-20 10:10 -0700
Re: Formatting of Language LRMs glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-08-03 04:37 +0000
Re: Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-06-20 12:09 -0700
Re: Formatting of Language LRMs glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-06-21 02:27 +0000
Re: Formatting of Language LRMs Kaz Kylheku <kaz@kylheku.com> - 2014-06-21 03:09 +0000
Re: Formatting of Language LRMs Joshua Cranmer 🐧 <Pidgeot18@verizon.net.invalid> - 2014-06-22 21:12 -0500
Re: VWG and K, was Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-06-22 21:47 -0700
RE: Formatting of Language LRMs "Costello, Roger L." <costello@mitre.org> - 2014-07-03 09:06 +0000
Re: Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-07-03 22:30 -0700
Re: syntax checkers, was Formatting of Language LRMs glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-04 17:35 +0000
Re: executable semantics, was Formatting of Language LRMs wclodius@earthlink.net (William Clodius) - 2014-07-04 15:53 -0600
Re: specifying semantics, was Formatting of Language LRMs seimarao@gmail.com - 2014-06-24 02:19 -0700
Re: specifying semantics, was Formatting of Language LRMs "lpsantil@gmail.com" <lpsantil@gmail.com> - 2014-06-24 13:12 -0700
Re: specifying semantics, was Formatting of Language LRMs George Neuner <gneuner2@comcast.net> - 2014-06-26 00:54 -0400
Re: specifying semantics, was Formatting of Language LRMs Andy Walker <news@cuboid.co.uk> - 2014-06-28 20:10 +0100
Re: specifying semantics, was Formatting of Language LRMs George Neuner <gneuner2@comcast.net> - 2014-06-28 22:43 -0400
Re: BNF, was specifying semantics wclodius@earthlink.net (William Clodius) - 2014-06-30 22:00 -0600
Re: specifying semantics, was Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-06-28 12:25 -0700
Re: specifying semantics, was Formatting of Language LRMs Andy Walker <news@cuboid.co.uk> - 2014-06-29 11:19 +0100
Re: specifying semantics, was Formatting of Language LRMs George Neuner <gneuner2@comcast.net> - 2014-06-29 07:56 -0400
Re: specifying semantics, was Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-06-29 11:49 -0700
Re: specifying semantics, was Formatting of Language LRMs Gene Wirchenko <genew@telus.net> - 2014-06-30 18:09 -0700
Re: specifying semantics, was Formatting of Language LRMs Ivan Godard <ivan@ootbcomp.com> - 2014-06-30 20:53 -0700
Re: Algol history, was specifying semantics anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-03 11:51 +0000
Re: Algol history, was specifying semantics Ivan Godard <ivan@ootbcomp.com> - 2014-07-03 22:20 -0700
Re: Algol history, was specifying semantics wclodius@earthlink.net (William Clodius) - 2014-07-04 15:52 -0600
Re: Algol history, was specifying semantics glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-07 05:49 +0000
Re: Algol history, was specifying semantics Ivan Godard <ivan@ootbcomp.com> - 2014-07-07 10:48 -0700
Re: Algol history, was specifying semantics glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-07 19:49 +0000
Re: Algol history, was specifying semantics glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-07 19:43 +0000
Re: specifying semantics, was Formatting of Language LRMs Gene Wirchenko <genew@telus.net> - 2014-07-03 21:44 -0700
Re: specifying semantics, was Formatting of Language LRMs anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-07-02 09:51 +0000
Re: specifying semantics, was Formatting of Language LRMs Stefan Monnier <monnier@iro.umontreal.ca> - 2014-07-03 10:15 -0400
Re: specifying semantics, was Formatting of Language LRMs glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-04 06:08 +0000
Re: specifying semantics, was Formatting of Language LRMs Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2014-07-04 08:51 +0200
Re: Parsing Fortran, was specifying semantics glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2014-07-04 17:53 +0000
Re: Parsing Fortran, was specifying semantics wclodius@earthlink.net (William Clodius) - 2014-07-04 15:57 -0600
Re: Formatting of Language LRMs mertesthomas@gmail.com - 2014-06-30 12:04 -0700
Re: Formatting of Language LRMs federation2005@netzero.com - 2014-07-28 17:55 -0700
Re: Formatting of Language LRMs federation2005@netzero.com - 2014-08-01 14:58 -0700
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