guix-devel/guix/scripts/repl.scm

208 lines
7.2 KiB
Scheme
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2018 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (guix scripts repl)
#:use-module (guix ui)
#:use-module (guix scripts)
#:use-module (guix utils)
#:use-module (guix packages)
#:use-module (gnu packages)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-37)
#:use-module (ice-9 match)
#:use-module (rnrs bytevectors)
#:autoload (system repl repl) (start-repl)
#:autoload (system repl server)
(make-tcp-server-socket make-unix-domain-server-socket)
#:export (machine-repl
guix-repl))
;;; Commentary:
;;;
;;; This command provides a Guile REPL
(define %default-options
`((type . guile)))
(define %options
(list (option '(#\h "help") #f #f
(lambda args
(show-help)
(exit 0)))
(option '(#\V "version") #f #f
(lambda args
(show-version-and-exit "guix repl")))
(option '(#\t "type") #t #f
(lambda (opt name arg result)
(alist-cons 'type (string->symbol arg) result)))
(option '("listen") #t #f
(lambda (opt name arg result)
(alist-cons 'listen arg result)))))
(define (show-help)
(display (G_ "Usage: guix repl [OPTIONS...]
Start a Guile REPL in the Guix execution environment.\n"))
(display (G_ "
-t, --type=TYPE start a REPL of the given TYPE"))
(newline)
(display (G_ "
-h, --help display this help and exit"))
(display (G_ "
-V, --version display version information and exit"))
(newline)
(show-bug-report-information))
(define (self-quoting? x)
"Return #t if X is self-quoting."
(letrec-syntax ((one-of (syntax-rules ()
((_) #f)
((_ pred rest ...)
(or (pred x)
(one-of rest ...))))))
(one-of symbol? string? pair? null? vector?
bytevector? number? boolean?)))
(define user-module
;; Module where we execute user code.
(let ((module (resolve-module '(guix-user) #f #f #:ensure #t)))
(beautify-user-module! module)
module))
(define* (machine-repl #:optional
(input (current-input-port))
(output (current-output-port)))
"Run a machine-usable REPL over ports INPUT and OUTPUT.
The protocol of this REPL is meant to be machine-readable and provides proper
support to represent multiple-value returns, exceptions, objects that lack a
read syntax, and so on. As such it is more convenient and robust than parsing
Guile's REPL prompt."
(define (value->sexp value)
(if (self-quoting? value)
`(value ,value)
`(non-self-quoting ,(object-address value)
,(object->string value))))
(write `(repl-version 0 0) output)
(newline output)
(force-output output)
(let loop ()
(match (read input)
((? eof-object?) #t)
(exp
(catch #t
(lambda ()
(let ((results (call-with-values
(lambda ()
(primitive-eval exp))
list)))
(write `(values ,@(map value->sexp results))
output)
(newline output)
(force-output output)))
(lambda (key . args)
(write `(exception ,key ,@(map value->sexp args)))
(newline output)
(force-output output)))
(loop)))))
(define (call-with-connection spec thunk)
"Dynamically-bind the current input and output ports according to SPEC and
call THUNK."
(if (not spec)
(thunk)
;; Note: the "PROTO:" prefix in SPEC is here so that we can eventually
;; parse things like "fd:123" in a non-ambiguous way.
(match (string-index spec #\:)
(#f
(leave (G_ "~A: invalid listen specification~%") spec))
(index
(let ((protocol (string-take spec index))
(address (string-drop spec (+ index 1))))
(define socket
(match protocol
("tcp"
(make-tcp-server-socket #:port (string->number address)))
("unix"
(make-unix-domain-server-socket #:path address))
(_
(leave (G_ "~A: unsupported protocol family~%")
protocol))))
(listen socket 10)
(let loop ()
(match (accept socket)
((connection . address)
(if (= AF_UNIX (sockaddr:fam address))
(info (G_ "accepted connection~%"))
(info (G_ "accepted connection from ~a~%")
(inet-ntop (sockaddr:fam address)
(sockaddr:addr address))))
(dynamic-wind
(const #t)
(lambda ()
(parameterize ((current-input-port connection)
(current-output-port connection))
(thunk)))
(lambda ()
(false-if-exception (close-port connection))
(info (G_ "connection closed~%"))))))
(loop)))))))
(define (guix-repl . args)
(define opts
;; Return the list of package names.
(args-fold* args %options
(lambda (opt name arg result)
(leave (G_ "~A: unrecognized option~%") name))
(lambda (arg result)
(leave (G_ "~A: extraneous argument~%") arg))
%default-options))
(with-error-handling
(let ((type (assoc-ref opts 'type)))
(call-with-connection (assoc-ref opts 'listen)
(lambda ()
(case type
((guile)
(save-module-excursion
(lambda ()
(set-current-module user-module)
(and=> (getenv "HOME")
(lambda (home)
(let ((guile (string-append home "/.guile")))
(when (file-exists? guile)
(load guile)))))
;; Do not exit repl on SIGINT.
((@@ (ice-9 top-repl) call-with-sigint)
(lambda ()
(start-repl))))))
((machine)
(machine-repl))
(else
(leave (G_ "~a: unknown type of REPL~%") type))))))))
;; Local Variables:
;; eval: (put 'call-with-connection 'scheme-indent-function 1)
;; End: