Changeset 23 for sizechecking/branches/macs/Exp.hs

Timestamp:

May 3, 2014, 5:01:55 PM (11 years ago)

Author:

gobi

Message:

expression

File:

• sizechecking/branches/macs/Exp.hs (modified) (1 diff)

sizechecking/branches/macs/Exp.hs

@@ -1 +1 @@
 module Exp where
 
-import Size
+import Lambda
+import Ops
+import Data.Supply as S
 
-class Exp l where
+class LOps l => Exp l where
     nil :: l [a]
     cons :: l a -> l [a] -> l [a]
-    match :: l [a] -> l b -> l (a -> [a] -> b) -> [b]
+    cons = infixopr ":" 5 (:)
+    match :: l [a] -> l b -> (l a -> l [a] -> l b) -> l b
+    cond :: l Bool -> l a -> l a -> l a
+    undefined :: l a
+
+instance Exp Q where
+    nil = Q []
+    cons x xs = Q ( unQ x : unQ xs )
+    match l nbranch cbranch = case unQ l of
+        [] -> nbranch
+        (x:xs) -> cbranch (Q x) (Q xs)
+    cond c tbranch fbranch = if unQ c then tbranch else fbranch
+    undefined = Prelude.undefined 
+instance Exp S where
+    nil = S $ \_ _ -> showString "[]"
+    undefined = S $ \_ _ -> showString "undefined"
+    match list nbranch cbranch = S $ \s p ->
+        let (s1, s2, ss) = S.split3 s
+            (s3, s4, s5) = S.split3 ss
+            v1           = S.supplyValue s4
+            showV1       = S $ \_ _ -> showVar v1
+            v2           = S.supplyValue s5
+            showV2       = S $ \_ _ -> showVar v2
+        in showParen (p>0) $ 
+            showString "case ".
+            unS list s1 0 .
+            showString " of [] => ".
+            unS nbranch s2 0 .
+            showString "; (" .  showVar v1 . showChar ':' . showVar v2 . showString ") => " .
+            unS (cbranch showV1 showV2) s3 0