guix/guix/import/json.scm
Ricardo Wurmus 7cef499bb0
import/json: json->code: Handle files with more than one definition.
* guix/import/json.scm (json->code): Convert JSON arrays to lists of package
definitions.
(json->scheme-file): Write all expressions to the target file.
2020-04-16 23:41:52 +02:00

103 lines
4.2 KiB
Scheme

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2014 David Thompson <davet@gnu.org>
;;; Copyright © 2015, 2016 Eric Bavier <bavier@member.fsf.org>
;;; Copyright © 2018, 2019 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2020 Ricardo Wurmus <rekado@elephly.net>
;;;
;;; 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 import json)
#:use-module (json)
#:use-module (guix http-client)
#:use-module (guix import utils)
#:use-module (guix import print)
#:use-module (ice-9 match)
#:use-module (ice-9 rdelim)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-2)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-34)
#:export (json-fetch
json->code
json->scheme-file))
(define* (json-fetch url
;; Note: many websites returns 403 if we omit a
;; 'User-Agent' header.
#:key (headers `((user-agent . "GNU Guile")
(Accept . "application/json"))))
"Return a representation of the JSON resource URL (a list or hash table), or
#f if URL returns 403 or 404. HEADERS is a list of HTTP headers to pass in
the query."
(guard (c ((and (http-get-error? c)
(let ((error (http-get-error-code c)))
(or (= 403 error)
(= 404 error))))
#f))
(let* ((port (http-fetch url #:headers headers))
(result (json->scm port)))
(close-port port)
result)))
(define (json->code file-name)
"Read FILE-NAME containing one ore more JSON package definitions and return
a list of S-expressions, or return #F when the JSON is invalid."
(catch 'json-invalid
(lambda ()
(let ((json (json-string->scm
(with-input-from-file file-name read-string))))
(match json
(#(packages ...)
;; To allow definitions to refer to one another, collect references
;; to local definitions and tell alist->package to ignore them.
(second
(memq #:result
(fold
(lambda (pkg names+result)
(match names+result
((#:names names #:result result)
(list #:names
(cons (assoc-ref pkg "name") names)
#:result
(append result
(list
(package->code (alist->package pkg names))
(string->symbol (assoc-ref pkg "name"))))))))
(list #:names '()
#:result '())
packages))))
(package
(list (package->code (alist->package json))
(string->symbol (assoc-ref json "name")))))))
(const #f)))
(define (json->scheme-file file)
"Convert the FILE containing a JSON package definition to a Scheme
representation and return the new file name (or #F on error)."
(and-let* ((sexprs (json->code file))
(file* (let* ((tempdir (or (getenv "TMPDIR") "/tmp"))
(template (string-append tempdir "/guix-XXXXXX"))
(port (mkstemp! template)))
(close-port port)
template)))
(call-with-output-file file*
(lambda (port)
(write '(use-modules (gnu)
(guix)
((guix licenses) #:prefix license:))
port)
(for-each (cut write <> port) sexprs)))
file*))