switch keyword return to pure; color pure and function names

grin/do.grin

@@ -7,8 +7,8 @@ sum n29 n30 n31 =
   if b2 then
     x <- do
       case CFalse of
-        CFalse -> return ()
-    return n29
+        CFalse -> pure ()
+    pure n29
   else
     n18 <- intAdd n30 1
     n28 <- intAdd n29 n30

grin/sum_opt.grin

@@ -5,7 +5,7 @@ main =
 sum n29 n30 n31 =
   b2 <- intGT n30 n31
   if b2 then
-    return n29
+    pure n29
   else
     n18 <- intAdd n30 1
     n28 <- intAdd n29 n30

grin/sum_simple.grin

@@ -9,29 +9,29 @@ upto m n = (CInt m') <- eval m
            (CInt n') <- eval n
            b' <- intGT m' n'
            if b' then
-            return (CNil)
+            pure (CNil)
            else
             m1' <- intAdd m' 1
             m1 <- store (CInt m1')
             p <- store (Fupto m1 n)
-            return (CCons m p)
+            pure (CCons m p)
 
 sum l = l2 <- eval l
         case l2 of
-          (CNil)       -> return (CInt 0)
+          (CNil)       -> pure (CInt 0)
           (CCons x xs) -> (CInt x') <- eval x
                           (CInt s') <- sum xs
                           ax' <- intAdd x' s'
-                          return (CInt ax')
+                          pure (CInt ax')
 
 eval q = v <- fetch q
          case v of
-          (CInt x'1)    -> return v
-          (CNil)        -> return v
-          (CCons y ys)  -> return v
+          (CInt x'1)    -> pure v
+          (CNil)        -> pure v
+          (CCons y ys)  -> pure v
           (Fupto a b)   -> w <- upto a b
                            update q w
-                           return w
+                           pure w
           (Fsum c)      -> z <- sum c
                            update q z
-                           return z
+                           pure z

src/ParseGrin.hs

@@ -12,7 +12,7 @@ import qualified Data.Set as Set
 import Grin
 import ReduceGrin
 
-keywords = Set.fromList ["case","of","return","fetch","store","update","if","then","else","do"]
+keywords = Set.fromList ["case","of","pure","fetch","store","update","if","then","else","do"]
 
 lineComment :: Parser ()
 lineComment = L.skipLineComment "--"
@@ -73,7 +73,7 @@ ifThenElse i = do
                    , Alt (TagPat (Tag C "False" 0)) e
                    ]
 
-simpleExp i = SReturn <$ kw "return" <*> value <|>
+simpleExp i = SReturn <$ kw "pure" <*> value <|>
               SStore <$ kw "store" <*> value <|>
               SFetch <$ kw "fetch" <*> var <|>
               SUpdate <$ kw "update" <*> var <*> value <|>

src/Pretty.hs

@@ -29,8 +29,8 @@ instance Pretty Exp where
       EBindF simpleexp lpat exp -> pretty lpat <+> text "<-" <+> pretty simpleexp <$$> pretty exp
       ECaseF val alts   -> keyword "case" <+> pretty val <+> keyword "of" <$$> indent 2 (vsep (map pretty alts))
       -- Simple Expr
-      SAppF name args   -> hsep (text name : map pretty args)
-      SReturnF val      -> text "return" <+> pretty val
+      SAppF name args   -> hsep ((cyan $ text name) : map pretty args)
+      SReturnF val      -> keyword "pure" <+> pretty val
       SStoreF val       -> keywordR "store" <+> pretty val
       SFetchF name      -> keywordR "fetch" <+> text name
       SUpdateF name val -> keywordR "update" <+> text name <+> pretty val