[PATCH 2/2] gnu: Add idris-lightyear.

[David Craven <david@craven.ch>]

* gnu/packages/haskell.scm (idris-lightyear): New variable.
---
 gnu/packages/haskell.scm | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/gnu/packages/haskell.scm b/gnu/packages/haskell.scm
index 2f75c6c37..54fdba72f 100644
--- a/gnu/packages/haskell.scm
+++ b/gnu/packages/haskell.scm
@@ -29,6 +29,7 @@
   #:use-module ((guix licenses) #:prefix license:)
   #:use-module (guix packages)
   #:use-module (guix download)
+  #:use-module (guix git-download)
   #:use-module (guix utils)
   #:use-module (guix build-system gnu)
   #:use-module (guix build-system haskell)
@@ -6747,6 +6748,51 @@ can be specified precisely in the type.  The language is closely related to
 Epigram and Agda.")
     (license license:bsd-3)))
 
+(define-public idris-lightyear
+  (let ((commit "6d65ad111b4bed2bc131396f8385528fc6b3678a")
+        (revision "1"))
+    (package
+      (name "idris-lightyear")
+      (version (string-append "0.1-" revision "."
+                              (string-take commit 7)))
+      (source (origin
+                (method git-fetch)
+                (uri (git-reference
+                      (url "https://github.com/ziman/lightyear")
+                      (commit commit)))
+                (file-name (string-append name "-" version "-checkout"))
+                (sha256
+                 (base32
+                  "1pkxnn3ryr0v0cin4nasw7kgkc9dnnpja1nfbj466mf3qv5s98af"))))
+      ;; Uses the gnu-build-system so that the IDRIS_LIBRARY_PATH is set.
+      (build-system gnu-build-system)
+      (native-inputs
+       `(("idris" ,idris)))
+      (arguments
+       `(#:phases
+         (modify-phases %standard-phases
+           (delete 'configure)
+           (delete 'build)
+           (delete 'check)
+           (replace 'install
+             (lambda* (#:key inputs outputs #:allow-other-keys)
+               (let* ((out (assoc-ref outputs "out"))
+                      (src (assoc-ref inputs "source"))
+                      (idris (assoc-ref inputs "idris"))
+                      (libs (string-append out "/idris/libs/lightyear")))
+                 (mkdir-p libs)
+                 (zero? (system* (string-append idris "/bin/idris")
+                          "--ibcsubdir" libs
+                          "--install" "lightyear.ipkg"))
+                 ;; Seems to be a bug in idris.
+                 #t))))))
+      (home-page "https://github.com/ziman/lightyear")
+      (synopsis "Lightweight parser combinator library for Idris")
+      (description "Lightweight parser combinator library for Idris, inspired
+by Parsec.  This package is used (almost) the same way as Parsec, except for one
+difference: backtracking.")
+      (license license:bsd-2))))
+
 (define-public ghc-base16-bytestring
   (package
     (name "ghc-base16-bytestring")
-- 
2.11.0