From: ludo@gnu.org (Ludovic Courtès)
To: Efraim Flashner <efraim@flashner.co.il>
Cc: guix-devel@gnu.org, David Thompson <davet@gnu.org>
Subject: Re: Adding wc to Bournish
Date: Wed, 15 Jun 2016 15:56:43 +0200 [thread overview]
Message-ID: <87shwed084.fsf@gnu.org> (raw)
In-Reply-To: <20160614105037.GC10636@debian-netbook> (Efraim Flashner's message of "Tue, 14 Jun 2016 13:50:37 +0300")
Efraim Flashner <efraim@flashner.co.il> skribis:
> From 09eef9cd841a7d212e024be0609168611923696b Mon Sep 17 00:00:00 2001
> From: Efraim Flashner <efraim@flashner.co.il>
> Date: Sun, 22 May 2016 14:56:06 +0300
> Subject: [PATCH] bournish: Add `wc' command.
>
> * guix/build/bournish.scm (lines+chars, only-files, wc-commands,
> wc-command-implementation, wc-l-command-implementation,
> wc-c-command-implementation): New variables.
s/variables/procedures/ :-)
> (%commands): Add wc command.
[...]
> +(define (only-files files)
> + (filter (lambda (file)
> + (catch 'system-error
> + (lambda ()
> + (stat file))
> + (lambda args
> + (let ((errno (system-error-errno args)))
> + (format (current-error-port) "~a: ~a~%"
> + file (strerror errno))
> + #f))))
> + files))
> +
> +(define (wc-command-implementation . files)
> + (for-each
> + (lambda (file)
> + (let-values (((lines chars)
> + (call-with-input-file file lines+chars)))
> + (format #t "~a ~a ~a~%" lines chars file)))
> + ((@@ (guix build bournish) only-files) files)))
I prefer the approach Ricardo suggested, I think it’s more concise and
clearer:
https://lists.gnu.org/archive/html/guix-devel/2016-06/msg00525.html
Also, note that @@ would not be needed here; @@ serves to access private
bindings within a specific module:
https://www.gnu.org/software/guile/manual/html_node/Using-Guile-Modules.html
Last, do not miss the bit about docstrings at:
https://www.gnu.org/software/guix/manual/html_node/Formatting-Code.html
:-)
With these changes, we’re all set. Thanks!
From a GSoC viewpoint, I think we must move to the compilation part
now. Specifically, I think the next step is to start parsing Bash
code.
For that we could use SILex + parse-lalr, but these are not the nicest
tools for the job. Better tools would be “parsing expression grammars”
(the (ice-9 peg) module in Guile 2.1) or parser combinators, though I
don’t think there’s a directly usable Guile library for that. Maybe
Eric or David can comment?
The goal is to have a parser that returns an abstract syntax tree (AST)
as an sexp:
(parse "(cd /foo; ls $HOME) && echo *.a ; echo done")
=>
'(sequence
(success-sequence
(subshell
(sequence (command "cd" "/foo")
(command "ls" (variable-ref "HOME"))))
(command "echo" (glob "*.a")))
(command "echo" "done"))
Thoughts?
Ludo’.
next prev parent reply other threads:[~2016-06-15 13:57 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-24 18:47 Adding wc to Bournish Efraim Flashner
2016-05-25 9:03 ` Ricardo Wurmus
2016-05-25 9:43 ` Efraim Flashner
2016-05-25 9:26 ` Ricardo Wurmus
2016-05-25 10:05 ` Efraim Flashner
2016-05-26 8:46 ` Ludovic Courtès
2016-05-26 17:50 ` Efraim Flashner
2016-05-26 19:27 ` Efraim Flashner
2016-05-27 13:37 ` Eric Bavier
2016-05-27 15:28 ` Taylan Ulrich Bayırlı/Kammer
2016-05-27 15:32 ` Thompson, David
2016-06-05 12:40 ` Efraim Flashner
2016-06-05 20:37 ` Ludovic Courtès
2016-06-07 7:41 ` Efraim Flashner
2016-06-08 15:43 ` Ludovic Courtès
2016-06-14 9:27 ` Efraim Flashner
2016-06-14 9:57 ` Ricardo Wurmus
2016-06-14 10:20 ` Efraim Flashner
2016-06-14 10:50 ` Efraim Flashner
2016-06-14 11:08 ` Ricardo Wurmus
2016-06-15 13:56 ` Ludovic Courtès [this message]
2016-06-15 20:28 ` Efraim Flashner
2016-06-23 8:34 ` Ludovic Courtès
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://guix.gnu.org/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87shwed084.fsf@gnu.org \
--to=ludo@gnu.org \
--cc=davet@gnu.org \
--cc=efraim@flashner.co.il \
--cc=guix-devel@gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/guix.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).