From 5a968225c3f97422c8c4ee1d8efe8042b52f5aa9 Mon Sep 17 00:00:00 2001
From: Alejandro Serrano <trupill@gmail.com>
Date: Tue, 17 Jun 2014 18:15:36 +0200
Subject: [PATCH] Initial skeleton for case split in elisp

---
 Language/Haskell/GhcMod/Info.hs |  5 ++++
 elisp/Makefile                  |  2 +-
 elisp/ghc-rewrite.el            | 42 +++++++++++++++++++++++++++++++++
 elisp/ghc.el                    |  3 +++
 4 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 elisp/ghc-rewrite.el

diff --git a/Language/Haskell/GhcMod/Info.hs b/Language/Haskell/GhcMod/Info.hs
index d07e554..353b3ae 100644
--- a/Language/Haskell/GhcMod/Info.hs
+++ b/Language/Haskell/GhcMod/Info.hs
@@ -388,6 +388,11 @@ initialBodyArgs (FnArgFunction:xs) vs (f:fs) = f : initialBodyArgs xs vs fs
 initialBodyArgs (FnArgNormal:xs)   (v:vs) fs = v : initialBodyArgs xs vs fs
 initialBodyArgs _                  _      _  = error "This should never happen" -- Lists are infinite
 
+-- Getting the initial body of function and instances differ
+-- This is because for functions we only use the parsed file
+-- (so the full file doesn't have to be type correct)
+-- but for instances we need to get information about the class
+
 initialFnBody :: DynFlags -> PprStyle -> G.HsType G.RdrName -> G.RdrName -> String
 initialFnBody dflag style ty name = 
   let fname = showOccName dflag style $ occName name  -- get function name
diff --git a/elisp/Makefile b/elisp/Makefile
index d77aed3..96bec8b 100644
--- a/elisp/Makefile
+++ b/elisp/Makefile
@@ -1,5 +1,5 @@
 SRCS = ghc.el ghc-func.el ghc-doc.el ghc-comp.el ghc-check.el ghc-process.el \
-       ghc-command.el ghc-info.el ghc-ins-mod.el ghc-indent.el
+       ghc-command.el ghc-info.el ghc-ins-mod.el ghc-indent.el ghc-rewrite.el
 EMACS = emacs
 DETECT = xemacs
 
diff --git a/elisp/ghc-rewrite.el b/elisp/ghc-rewrite.el
new file mode 100644
index 0000000..c3235c4
--- /dev/null
+++ b/elisp/ghc-rewrite.el
@@ -0,0 +1,42 @@
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;
+;;; ghc-rewrite.el
+;;;
+
+;; Author:  Alejandro Serrano <trupill@gmail.com>
+;; Created: Jun 17, 2014
+
+;;; Code:
+
+(require 'ghc-func)
+(require 'ghc-process)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;
+;;; Case splitting
+;;;
+
+(ghc-defstruct sinfo beg-line beg-column end-line end-column info)
+
+(defun ghc-case-split ()
+  (interactive)
+  (let ((info (ghc-obtain-case-split)))
+    (if (null info)
+	(message "Cannot split in cases")
+	(let ((varinfo (car info))
+	      (declinfo (cadr info))
+	      (cases (caddr info)))
+	  (message cases)
+	  )
+      )
+    )
+  )
+
+(defun ghc-obtain-case-split ()
+  (let* ((ln (int-to-string (line-number-at-pos)))
+	 (cn (int-to-string (1+ (current-column))))
+	 (file (buffer-file-name))
+	 (cmd (format "split %s %s %s\n" file ln cn)))
+    (ghc-sync-process cmd)))
+
+(provide 'ghc-rewrite)
diff --git a/elisp/ghc.el b/elisp/ghc.el
index 50b3146..85c2c9d 100644
--- a/elisp/ghc.el
+++ b/elisp/ghc.el
@@ -40,6 +40,7 @@
 (require 'ghc-command)
 (require 'ghc-ins-mod)
 (require 'ghc-indent)
+(require 'ghc-rewrite)
 (require 'dabbrev)
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -72,6 +73,7 @@
 (defvar ghc-hoogle-key      (format "\C-c%c" (ghc-find-C-h)))
 (defvar ghc-shallower-key   "\C-c<")
 (defvar ghc-deeper-key      "\C-c>")
+(defvar ghc-case-split-key  "\C-c\C-p")
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;
@@ -104,6 +106,7 @@
     (define-key haskell-mode-map ghc-hoogle-key      'haskell-hoogle)
     (define-key haskell-mode-map ghc-shallower-key   'ghc-make-indent-shallower)
     (define-key haskell-mode-map ghc-deeper-key      'ghc-make-indent-deeper)
+    (define-key haskell-mode-map ghc-case-split-key  'ghc-case-split)
     (ghc-comp-init)
     (setq ghc-initialized t))
   (ghc-import-module)