# HG changeset patch
# User Adam Chlipala <adamc@hcoop.net>
# Date 1212955711 14400
# Node ID d8850cc06d24759c4089cb8baf3995f1ab3008f1
# Parent  067029c748e94e92a37deed5f2765542352016ac
Reducing known record projections

diff -r 067029c748e9 -r d8850cc06d24 src/reduce.sml
--- a/src/reduce.sml	Sun Jun 08 16:02:26 2008 -0400
+++ b/src/reduce.sml	Sun Jun 08 16:08:31 2008 -0400
@@ -144,6 +144,12 @@
       | ECApp ((ECAbs (_, _, e1), loc), c) =>
         #1 (reduceExp env (subConInExp (0, c) e1))
 
+      | EField ((ERecord xes, _), (CName x, _), _) =>
+        (case List.find (fn ((CName x', _), _) => x' = x
+                          | _ => false) xes of
+             SOME (_, e) => #1 e
+           | NONE => e)
+
       | _ => e
 
 and reduceExp env = U.Exp.mapB {kind = kind, con = con, exp = exp, bind = bind} env
diff -r 067029c748e9 -r d8850cc06d24 tests/reduce.lac
--- a/tests/reduce.lac	Sun Jun 08 16:02:26 2008 -0400
+++ b/tests/reduce.lac	Sun Jun 08 16:08:31 2008 -0400
@@ -14,7 +14,12 @@
 con c6 = apply id int
 con c7 = apply (fst int) string
 
-val grab = fn n :: Name => fn t :: Type => fn fs :: {Type} =>
+val tickle = fn n :: Name => fn t :: Type => fn fs :: {Type} =>
         fn x : $([n = t] ++ fs) => x
-val grabA = grab[#A][int][[B = string]]
-val test_grabA = grabA {A = 6, B = "13"}
+val tickleA = tickle[#A][int][[B = string]]
+val test_tickleA = tickleA {A = 6, B = "13"}
+
+val grab = fn n :: Name => fn t ::: Type => fn fs ::: {Type} =>
+        fn x : $([n = t] ++ fs) => x.n
+val test_grab1 = grab[#A] {A = 6, B = "13"}
+val test_grab2 = grab[#B] {A = 6, B = "13"}