guix-devel/guix/import/cran.scm

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;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015 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 cran)
#:use-module (ice-9 match)
#:use-module (ice-9 regex)
#:use-module (srfi srfi-1)
#:use-module (sxml simple)
#:use-module (sxml match)
#:use-module (sxml xpath)
#:use-module (guix http-client)
#:use-module (guix hash)
#:use-module (guix store)
#:use-module (guix base32)
#:use-module ((guix download) #:select (download-to-store))
#:use-module (guix import utils)
#:export (cran->guix-package))
;;; Commentary:
;;;
;;; Generate a package declaration template for the latest version of an R
;;; package on CRAN, using the HTML description downloaded from
;;; cran.r-project.org.
;;;
;;; Code:
(define string->license
(match-lambda
("AGPL-3" 'agpl3+)
("Artistic-2.0" 'artistic2.0)
("Apache License 2.0" 'asl2.0)
("BSD_2_clause" 'bsd-2)
("BSD_3_clause" 'bsd-3)
("GPL-2" 'gpl2+)
("GPL-3" 'gpl3+)
("LGPL-2" 'lgpl2.0+)
("LGPL-2.1" 'lgpl2.1+)
("LGPL-3" 'lgpl3+)
("MIT" 'x11)
((x) (string->license x))
((lst ...) `(list ,@(map string->license lst)))
(_ #f)))
(define (format-inputs names)
"Generate a sorted list of package inputs from a list of package NAMES."
(map (lambda (name)
(list name (list 'unquote (string->symbol name))))
(sort names string-ci<?)))
(define* (maybe-inputs package-inputs #:optional (type 'inputs))
"Given a list of PACKAGE-INPUTS, tries to generate the TYPE field of a
package definition."
(match package-inputs
(()
'())
((package-inputs ...)
`((,type (,'quasiquote ,(format-inputs package-inputs)))))))
(define (table-datum tree label)
"Extract the datum node following a LABEL in the sxml table TREE. Only the
first cell of a table row is considered a label cell."
((node-pos 1)
((sxpath `(xhtml:tr
(xhtml:td 1) ; only first cell can contain label
(equal? ,label)
,(node-parent tree) ; go up to label cell
,(node-parent tree) ; go up to matching row
(xhtml:td 2))) ; select second cell
tree)))
(define %cran-url "http://cran.r-project.org/web/packages/")
(define (cran-fetch name)
"Return an sxml representation of the CRAN page for the R package NAME,
or #f on failure. NAME is case-sensitive."
;; This API always returns the latest release of the module.
(let ((cran-url (string-append %cran-url name)))
(false-if-exception
(xml->sxml (http-fetch cran-url)
#:trim-whitespace? #t
#:namespaces '((xhtml . "http://www.w3.org/1999/xhtml"))
#:default-entity-handler
(lambda (port name)
(case name
((nbsp) " ")
((ge) ">=")
((gt) ">")
((lt) "<")
(else
(format (current-warning-port)
"~a:~a:~a: undefined entitity: ~a\n"
cran-url (port-line port) (port-column port)
name)
(symbol->string name))))))))
(define (cran-sxml->sexp sxml)
"Return the `package' s-expression for a CRAN package from the SXML
representation of the package page."
(define (nodes->text nodeset)
(string-join ((sxpath '(// *text*)) nodeset) " "))
(define (guix-name name)
(if (string-prefix? "r-" name)
(string-downcase name)
(string-append "r-" (string-downcase name))))
(sxml-match-let*
(((*TOP* (xhtml:html
,head
(xhtml:body
(xhtml:h2 ,name-and-synopsis)
(xhtml:p ,description)
,summary
(xhtml:h4 "Downloads:") ,downloads
. ,rest)))
sxml))
(let* ((name (match:prefix (string-match ": " name-and-synopsis)))
(synopsis (match:suffix (string-match ": " name-and-synopsis)))
(version (nodes->text (table-datum summary "Version:")))
(license ((compose string->license nodes->text)
(table-datum summary "License:")))
(home-page (nodes->text ((sxpath '((xhtml:a 1)))
(table-datum summary "URL:"))))
(source-url (string-append "mirror://cran/"
;; Remove double dots, because we want an
;; absolute path.
(regexp-substitute/global
#f "\\.\\./"
(string-join
((sxpath '((xhtml:a 1) @ href *text*))
(table-datum downloads
" Package source: ")))
'pre 'post)))
(tarball (with-store store (download-to-store store source-url)))
(sysdepends (map match:substring
(list-matches
"[^ ]+"
;; Strip off comma and parenthetical
;; expressions.
(regexp-substitute/global
#f "(,|\\([^\\)]+\\))"
(nodes->text (table-datum summary
"SystemRequirements:"))
'pre 'post))))
(imports (map guix-name
((sxpath '(// xhtml:a *text*))
(table-datum summary "Imports:")))))
`(package
(name ,(guix-name name))
(version ,version)
(source (origin
(method url-fetch)
(uri (cran-uri ,name version))
(sha256
(base32
,(bytevector->nix-base32-string (file-sha256 tarball))))))
(build-system r-build-system)
,@(maybe-inputs sysdepends)
,@(maybe-inputs imports 'propagated-inputs)
(home-page ,(if (string-null? home-page)
(string-append %cran-url name)
home-page))
(synopsis ,synopsis)
;; Use double spacing
(description ,(regexp-substitute/global #f "\\. \\b" description
'pre ". " 'post))
(license ,license)))))
(define (cran->guix-package package-name)
"Fetch the metadata for PACKAGE-NAME from cran.r-project.org, and return the
`package' s-expression corresponding to that package, or #f on failure."
(let ((module-meta (cran-fetch package-name)))
(and=> module-meta cran-sxml->sexp)))