diff options
| author |  Adam Chlipala <adamc@hcoop.net> | 2009-10-20 10:19:00 -0400 |
|---|---|---|
| committer | Adam Chlipala <adamc@hcoop.net> | 2009-10-20 10:19:00 -0400 |
| commit | eafb2bfc151efd5fe9a18dd5bba14141a1b832cf (patch) | |
| tree | 800ab89ca52c3ef6e7df0f9420292131459f0e47 /src/urweb.grm | |
| parent | 64783736b3c002c095640c0bf16b48994a44869c (diff) | |
Add tuple pattern-matching at the constructor level
Diffstat (limited to 'src/urweb.grm')
| -rw-r--r-- | src/urweb.grm | 29 |
1 files changed, 26 insertions, 3 deletions
diff --git a/src/urweb.grm b/src/urweb.grm index edd93d96..38d7d60d 100644 --- a/src/urweb.grm +++ b/src/urweb.grm @@ -242,6 +242,8 @@ fun patType loc (p : pat) = | csts of exp | cstopt of exp + | ckl of (string * kind option) list + | pmode of prop_kind * exp | pkind of prop_kind | prule of exp @@ -847,14 +849,35 @@ cargp : SYMBOL (fn (c, k) => ((CAbs ("_", NONE, c), loc), (KArrow ((KWild, loc), k), loc)) end) - | LPAREN SYMBOL DCOLON kind RPAREN (fn (c, k) => + | LPAREN SYMBOL kopt ckl RPAREN (fn (c, k) => let val loc = s (LPARENleft, RPARENright) + val ckl = (SYMBOL, kopt) :: ckl + val ckl = map (fn (x, ko) => (x, case ko of + NONE => (KWild, loc) + | SOME k => k)) ckl in - ((CAbs (SYMBOL, SOME kind, c), loc), - (KArrow (kind, k), loc)) + case ckl of + [(x, k')] => ((CAbs (SYMBOL, SOME k', c), loc), + (KArrow (k', k), loc)) + | _ => + let + val k' = (KTuple (map #2 ckl), loc) + + val c = foldr (fn ((x, k), c) => + (CAbs (x, SOME k, c), loc)) c ckl + val v = (CVar ([], "$x"), loc) + val c = ListUtil.foldli (fn (i, _, c) => + (CApp (c, (CProj (v, i + 1), loc)), + loc)) c ckl + in + ((CAbs ("$x", SOME k', c), loc), + (KArrow (k', k), loc)) + end end) +ckl : ([]) + | COMMA SYMBOL kopt ckl ((SYMBOL, kopt) :: ckl) path : SYMBOL ([], SYMBOL) | CSYMBOL DOT path (let val (ms, x) = path in (CSYMBOL :: ms, x) end) |