gnu: Add emacs-parsec.

* gnu/packages/emacs-xyz.scm (emacs-parsec): New variable.

Signed-off-by: Nicolas Goaziou <mail@nicolasgoaziou.fr>

gnu/packages/emacs-xyz.scm

@@ -15009,6 +15009,34 @@ and @code{erc-send-modify-hook} to download and show images.")
     (description "This package provides a list manipulation library for Emacs.")
     (license license:gpl3+)))
 
+(define-public emacs-parsec
+  ;; Last release is too old (2016).
+  (let ((revision "0")
+        (commit "2cbbbc2254aa7bcaa4fb5e07c8c1bf2f381dba26"))
+    (package
+      (name "emacs-parsec")
+      (version (git-version "0.1.3" revision commit))
+      (source
+       (origin
+         (method git-fetch)
+         (uri (git-reference
+               (url "https://github.com/cute-jumper/parsec.el")
+               (commit commit)))
+         (file-name (git-file-name name version))
+         (sha256
+          (base32 "1g1s8s45g3kkbi3h7w0pmadmzdswb64mkdvdpg2lihg341kx37gm"))))
+      (build-system emacs-build-system)
+      (home-page "https://github.com/cute-jumper/parsec.el")
+      (synopsis "Parser combinator library for Emacs Lisp")
+      (description
+       "Parsec is a parser combinator library for Emacs Lisp, similar to
+Haskell's Parsec library.  It contains most of the parser combinators in
+Text.Parsec.Combinator, and more combinators can be added if necessary!  Most
+of the parser combinators have the same behavior as their Haskell
+counterparts.  Parsec also comes with a simple error handling mechanism so
+that it can display an error message showing how the parser fails.")
+      (license license:gpl3+))))
+
 (define-public emacs-move-text
   (package
     (name "emacs-move-text")