import: hackage: Support recursive importing.

* guix/import/hackage.scm (hackage-recursive-import): New procedure.
(hackage-module->sexp): Return dependencies alongside dependencies.
(hackage->guix-package): Memoize results.
* guix/scripts/import/hackage.scm (show-help, %options, guix-import-hackage):
Support recursive importing.
* doc/guix.texi (Invoking guix import): Document option.

3 files changed, 102 insertions, 64 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 85f51210a3..a9bb6d864a 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -6661,6 +6661,11 @@ The value associated with a flag has to be either the symbol
 has to conform to the Cabal file format definition.  The default value
 associated with the keys @code{os}, @code{arch} and @code{impl} is
 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
+@item --recursive
+@itemx -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.
 @end table
 
 The command below imports metadata for the latest version of the
diff --git a/guix/import/hackage.scm b/guix/import/hackage.scm
index 3b138f8c98..3c00f680bf 100644
--- a/guix/import/hackage.scm
+++ b/guix/import/hackage.scm
@@ -30,15 +30,17 @@
   #:use-module ((guix utils) #:select (package-name->name+version
                                        canonical-newline-port))
   #:use-module (guix http-client)
-  #:use-module ((guix import utils) #:select (factorize-uri))
+  #:use-module ((guix import utils) #:select (factorize-uri recursive-import))
   #:use-module (guix import cabal)
   #:use-module (guix store)
   #:use-module (guix hash)
   #:use-module (guix base32)
+  #:use-module (guix memoization)
   #:use-module (guix upstream)
   #:use-module (guix packages)
   #:use-module ((guix utils) #:select (call-with-temporary-output-file))
   #:export (hackage->guix-package
+            hackage-recursive-import
             %hackage-updater
 
             guix-package->hackage-name
@@ -205,32 +207,34 @@ representation of a Cabal file as produced by 'read-cabal'."
   (define source-url
     (hackage-source-url name version))
 
+  (define hackage-dependencies
+    ((compose (cut filter-dependencies <>
+                   (cabal-package-name cabal))
+              (cut cabal-dependencies->names <>))
+     cabal))
+
+  (define hackage-native-dependencies
+    ((compose (cut filter-dependencies <>
+                   (cabal-package-name cabal))
+              ;; FIXME: Check include-test-dependencies?
+              (lambda (cabal)
+                (append (if include-test-dependencies?
+                            (cabal-test-dependencies->names cabal)
+                            '())
+                        (cabal-custom-setup-dependencies->names cabal))))
+     cabal))
+
   (define dependencies
-    (let ((names
-           (map hackage-name->package-name
-                ((compose (cut filter-dependencies <>
-                               (cabal-package-name cabal))
-                          (cut cabal-dependencies->names <>))
-                 cabal))))
-      (map (lambda (name)
-             (list name (list 'unquote (string->symbol name))))
-           names)))
+    (map (lambda (name)
+           (list name (list 'unquote (string->symbol name))))
+         (map hackage-name->package-name
+              hackage-dependencies)))
 
   (define native-dependencies
-    (let ((names
-           (map hackage-name->package-name
-                ((compose (cut filter-dependencies <>
-                               (cabal-package-name cabal))
-                          ;; FIXME: Check include-test-dependencies?
-                          (lambda (cabal)
-                            (append (if include-test-dependencies?
-                                        (cabal-test-dependencies->names cabal)
-                                        '())
-                                    (cabal-custom-setup-dependencies->names cabal))))
-                 cabal))))
-      (map (lambda (name)
-             (list name (list 'unquote (string->symbol name))))
-           names)))
+    (map (lambda (name)
+           (list name (list 'unquote (string->symbol name))))
+         (map hackage-name->package-name
+              hackage-native-dependencies)))
   
   (define (maybe-inputs input-type inputs)
     (match inputs
@@ -247,31 +251,35 @@ representation of a Cabal file as produced by 'read-cabal'."
 
   (let ((tarball (with-store store
                    (download-to-store store source-url))))
-    `(package
-       (name ,(hackage-name->package-name name))
-       (version ,version)
-       (source (origin
-                 (method url-fetch)
-                 (uri (string-append ,@(factorize-uri source-url version)))
-                 (sha256
-                  (base32
-                   ,(if tarball
-                        (bytevector->nix-base32-string (file-sha256 tarball))
-                        "failed to download tar archive")))))
-       (build-system haskell-build-system)
-       ,@(maybe-inputs 'inputs dependencies)
-       ,@(maybe-inputs 'native-inputs native-dependencies)
-       ,@(maybe-arguments)
-       (home-page ,(cabal-package-home-page cabal))
-       (synopsis ,(cabal-package-synopsis cabal))
-       (description ,(cabal-package-description cabal))
-       (license ,(string->license (cabal-package-license cabal))))))
+    (values
+     `(package
+        (name ,(hackage-name->package-name name))
+        (version ,version)
+        (source (origin
+                  (method url-fetch)
+                  (uri (string-append ,@(factorize-uri source-url version)))
+                  (sha256
+                   (base32
+                    ,(if tarball
+                         (bytevector->nix-base32-string (file-sha256 tarball))
+                         "failed to download tar archive")))))
+        (build-system haskell-build-system)
+        ,@(maybe-inputs 'inputs dependencies)
+        ,@(maybe-inputs 'native-inputs native-dependencies)
+        ,@(maybe-arguments)
+        (home-page ,(cabal-package-home-page cabal))
+        (synopsis ,(cabal-package-synopsis cabal))
+        (description ,(cabal-package-description cabal))
+        (license ,(string->license (cabal-package-license cabal))))
+     (append hackage-dependencies hackage-native-dependencies))))
 
-(define* (hackage->guix-package package-name #:key
-                                (include-test-dependencies? #t)
-                                (port #f)
-                                (cabal-environment '()))
-  "Fetch the Cabal file for PACKAGE-NAME from hackage.haskell.org, or, if the
+(define hackage->guix-package
+  (memoize
+   (lambda* (package-name #:key
+                          (include-test-dependencies? #t)
+                          (port #f)
+                          (cabal-environment '()))
+     "Fetch the Cabal file for PACKAGE-NAME from hackage.haskell.org, or, if the
 called with keyword parameter PORT, from PORT.  Return the `package'
 S-expression corresponding to that package, or #f on failure.
 CABAL-ENVIRONMENT is an alist defining the environment in which the Cabal
@@ -281,13 +289,19 @@ symbol 'true' or 'false'.  The value associated with other keys has to conform
 to the Cabal file format definition.  The default value associated with the
 keys \"os\", \"arch\" and \"impl\" is \"linux\", \"x86_64\" and \"ghc\"
 respectively."
-  (let ((cabal-meta (if port
-                        (read-cabal (canonical-newline-port port))
-                        (hackage-fetch package-name))))
-    (and=> cabal-meta (compose (cut hackage-module->sexp <>
-                                    #:include-test-dependencies? 
-                                    include-test-dependencies?)
-                               (cut eval-cabal <> cabal-environment)))))
+     (let ((cabal-meta (if port
+                           (read-cabal (canonical-newline-port port))
+                           (hackage-fetch package-name))))
+       (and=> cabal-meta (compose (cut hackage-module->sexp <>
+                                       #:include-test-dependencies?
+                                       include-test-dependencies?)
+                                  (cut eval-cabal <> cabal-environment)))))))
+
+(define* (hackage-recursive-import package-name . args)
+  (recursive-import package-name #f
+                    #:repo->guix-package (lambda (name repo)
+                                           (apply hackage->guix-package (cons name args)))
+                    #:guix-name hackage-name->package-name))
 
 (define (hackage-package? package)
   "Return #t if PACKAGE is a Haskell package from Hackage."
diff --git a/guix/scripts/import/hackage.scm b/guix/scripts/import/hackage.scm
index 969f637846..f4aac61078 100644
--- a/guix/scripts/import/hackage.scm
+++ b/guix/scripts/import/hackage.scm
@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2015 Federico Beffa <beffa@fbengineering.ch>
+;;; Copyright © 2018 Ricardo Wurmus <rekado@elephly.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -26,6 +27,7 @@
   #: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-hackage))
@@ -57,6 +59,8 @@ version.\n"))
   (display (G_ "
   -h, --help                   display this help and exit"))
   (display (G_ "
+  -r, --recursive              import packages recursively"))
+  (display (G_ "
   -s, --stdin                  read from standard input"))
   (display (G_ "
   -t, --no-test-dependencies   don't include test-only dependencies"))
@@ -89,6 +93,9 @@ version.\n"))
                    (alist-cons 'cabal-environment (read/eval arg)
                                (alist-delete 'cabal-environment
                                              result))))
+         (option '(#\r "recursive") #f #f
+                 (lambda (opt name arg result)
+                   (alist-cons 'recursive #t result)))
          %standard-import-options))
 
 
@@ -107,15 +114,27 @@ version.\n"))
                 %default-options))
 
   (define (run-importer package-name opts error-fn)
-    (let ((sexp (hackage->guix-package
-                 package-name
-                 #:include-test-dependencies?
-                 (assoc-ref opts 'include-test-dependencies?)
-                 #:port (if (assoc-ref opts 'read-from-stdin?)
-                            (current-input-port)
-                            #f)
-                 #:cabal-environment
-                 (assoc-ref opts 'cabal-environment))))
+    (let* ((arguments (list
+                       package-name
+                       #:include-test-dependencies?
+                       (assoc-ref opts 'include-test-dependencies?)
+                       #:port (if (assoc-ref opts 'read-from-stdin?)
+                                  (current-input-port)
+                                  #f)
+                       #:cabal-environment
+                       (assoc-ref opts 'cabal-environment)))
+           (sexp (if (assoc-ref opts 'recursive)
+                     ;; Recursive import
+                     (map (match-lambda
+                            ((and ('package ('name name) . rest) pkg)
+                             `(define-public ,(string->symbol name)
+                                ,pkg))
+                            (_ #f))
+                          (reverse
+                           (stream->list
+                            (apply hackage-recursive-import arguments))))
+                     ;; Single import
+                     (apply hackage->guix-package arguments))))
       (unless sexp (error-fn))
       sexp))