Initial work on refining variable

src/GHCModi.hs

@@ -146,6 +146,7 @@ loop opt set mvar = do
         "type"   -> showType set arg
         "split"  -> doSplit set arg
         "sig"    -> doSig set arg
+        "refine" -> doRefine set arg
         "boot"   -> bootIt set
         "browse" -> browseIt set arg
         "quit"   -> return ("quit", False, set)
@@ -273,6 +274,15 @@ doSig set fileArg  = do
     ret <- sig file (read line) (read column)
     return (ret, True, set')
 
+doRefine :: Set FilePath
+         -> FilePath
+         -> GhcMod (String, Bool, Set FilePath)
+doRefine set fileArg  = do
+    let [file, line, column, expr] = words fileArg
+    set' <- newFileSet set file
+    ret <- rewrite file (read line) (read column) expr
+    return (ret, True, set')
+
 ----------------------------------------------------------------
 
 bootIt :: Set FilePath