[bug#32046] [PATCH] import: gem: Add recursive import.

[Oleg Pykhalov]

* doc/guix.texi (Invoking guix import): Document gem recursive import.
* guix/import/gem.scm (gem->guix-package): Return package and dependencies
values.
(gem-recursive-import): New procedure.
* guix/scripts/import/gem.scm (show-help, %options): Add recursive option.
(guix-import-gem): Use 'gem-recursive-import'.
---
 doc/guix.texi               |  8 ++++++
 guix/import/gem.scm         | 49 ++++++++++++++++++++++---------------
 guix/scripts/import/gem.scm | 26 ++++++++++++++++----
 3 files changed, 58 insertions(+), 25 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 841bc2a34..fa24bcf28 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -6370,6 +6370,14 @@ The command below imports metadata for the @code{rails} 
Ruby package:
 guix import gem rails
 @end example
 
address@hidden @code
address@hidden --recursive
address@hidden -r
+Traverse the dependency graph of the given upstream package recursively
+and generate package expressions for all those packages that are not yet
+in Guix.
address@hidden table
+
 @item cpan
 @cindex CPAN
 Import metadata from @uref{https://www.metacpan.org/, address@hidden
diff --git a/guix/import/gem.scm b/guix/import/gem.scm
index 646163fb7..9e6d2e72e 100644
--- a/guix/import/gem.scm
+++ b/guix/import/gem.scm
@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2015 David Thompson <address@hidden>
 ;;; Copyright © 2016 Ben Woodcroft <address@hidden>
+;;; Copyright © 2018 Oleg Pykhalov <address@hidden>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -20,6 +21,7 @@
 (define-module (guix import gem)
   #:use-module (ice-9 match)
   #:use-module (ice-9 pretty-print)
+  #:use-module (ice-9 receive)
   #:use-module (srfi srfi-1)
   #:use-module (rnrs bytevectors)
   #:use-module (json)
@@ -33,7 +35,8 @@
   #:use-module (guix base32)
   #:use-module (guix build-system ruby)
   #:export (gem->guix-package
-            %gem-updater))
+            %gem-updater
+            gem-recursive-import))
 
 (define (rubygems-fetch name)
   "Return an alist representation of the RubyGems metadata for the package 
NAME,
@@ -115,29 +118,30 @@ VERSION, HASH, HOME-PAGE, DESCRIPTION, DEPENDENCIES, and 
LICENSES."
                  ((license) (license->symbol license))
                  (_ `(list ,@(map license->symbol licenses)))))))
 
-(define* (gem->guix-package package-name #:optional version)
+(define* (gem->guix-package package-name #:optional (repo 'rubygems) version)
   "Fetch the metadata for PACKAGE-NAME from rubygems.org, and return the
 `package' s-expression corresponding to that package, or #f on failure."
   (let ((package (rubygems-fetch package-name)))
     (and package
-         (let ((name         (assoc-ref package "name"))
-               (version      (assoc-ref package "version"))
-               (hash         (assoc-ref package "sha"))
-               (synopsis     (assoc-ref package "info")) ; nothing better to 
use
-               (description  (beautify-description
-                              (assoc-ref package "info")))
-               (home-page    (assoc-ref package "homepage_uri"))
-               (dependencies (map (lambda (dep)
-                                    (let ((name (assoc-ref dep "name")))
-                                      (if (string=? name "bundler")
-                                          "bundler" ; special case, no prefix
-                                          (ruby-package-name name))))
-                                  (assoc-ref* package "dependencies"
-                                              "runtime")))
-               (licenses     (map string->license
-                                  (assoc-ref package "licenses"))))
-           (make-gem-sexp name version hash home-page synopsis
-                          description dependencies licenses)))))
+         (let* ((name         (assoc-ref package "name"))
+                (version      (assoc-ref package "version"))
+                (hash         (assoc-ref package "sha"))
+                (synopsis     (assoc-ref package "info")) ; nothing better to 
use
+                (description  (beautify-description
+                               (assoc-ref package "info")))
+                (home-page    (assoc-ref package "homepage_uri"))
+                (dependencies-names (map (lambda (dep) (assoc-ref dep "name"))
+                                         (assoc-ref* package "dependencies" 
"runtime")))
+                (dependencies (map (lambda (dep)
+                                     (if (string=? dep "bundler")
+                                         "bundler" ; special case, no prefix
+                                         (ruby-package-name dep)))
+                                   dependencies-names))
+                (licenses     (map string->license
+                                   (assoc-ref package "licenses"))))
+           (values (make-gem-sexp name version hash home-page synopsis
+                                  description dependencies licenses)
+                   dependencies-names)))))
 
 (define (guix-package->gem-name package)
   "Given a PACKAGE built from rubygems.org, return the name of the
@@ -192,3 +196,8 @@ package on RubyGems."
    (description "Updater for RubyGem packages")
    (pred gem-package?)
    (latest latest-release)))
+
+(define* (gem-recursive-import package-name #:optional version)
+  (recursive-import package-name '()
+                    #:repo->guix-package gem->guix-package
+                    #:guix-name ruby-package-name))
diff --git a/guix/scripts/import/gem.scm b/guix/scripts/import/gem.scm
index 349a0a072..64afbd464 100644
--- a/guix/scripts/import/gem.scm
+++ b/guix/scripts/import/gem.scm
@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2015 David Thompson <address@hidden>
+;;; Copyright © 2018 Oleg Pykhalov <address@hidden>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -25,6 +26,7 @@
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-11)
   #:use-module (srfi srfi-37)
+  #:use-module (srfi srfi-41)
   #:use-module (ice-9 match)
   #:use-module (ice-9 format)
   #:export (guix-import-gem))
@@ -44,6 +46,8 @@ Import and convert the RubyGems package for PACKAGE-NAME.\n"))
   -h, --help             display this help and exit"))
   (display (G_ "
   -V, --version          display version information and exit"))
+  (display (G_ "
+  -r, --recursive        generate package expressions for all Gem packages 
that are not yet in Guix"))
   (newline)
   (show-bug-report-information))
 
@@ -56,6 +60,9 @@ Import and convert the RubyGems package for PACKAGE-NAME.\n"))
          (option '(#\V "version") #f #f
                  (lambda args
                    (show-version-and-exit "guix import pypi")))
+         (option '(#\r "recursive") #f #f
+                 (lambda (opt name arg result)
+                   (alist-cons 'recursive #t result)))
          %standard-import-options))
 
 
@@ -81,11 +88,20 @@ Import and convert the RubyGems package for 
PACKAGE-NAME.\n"))
                            (reverse opts))))
     (match args
       ((package-name)
-       (let ((sexp (gem->guix-package package-name)))
-         (unless sexp
-           (leave (G_ "failed to download meta-data for package '~a'~%")
-                  package-name))
-         sexp))
+       (if (assoc-ref opts 'recursive)
+           (map (match-lambda
+                  ((and ('package ('name name) . rest) pkg)
+                   `(define-public ,(string->symbol name)
+                      ,pkg))
+                  (_ #f))
+                (reverse
+                 (stream->list
+                  (gem-recursive-import package-name 'rubygems))))
+           (let ((sexp (gem->guix-package package-name)))
+             (unless sexp
+               (leave (G_ "failed to download meta-data for package '~a'~%")
+                      package-name))
+             sexp)))
       (()
        (leave (G_ "too few arguments~%")))
       ((many ...)
-- 
2.18.0