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authorGravatar Adam Chlipala <adam@chlipala.net>2012-07-25 14:04:59 -0400
committerGravatar Adam Chlipala <adam@chlipala.net>2012-07-25 14:04:59 -0400
commitb2f6e6a5501937c58cbd8eb9b5d90ceae0321386 (patch)
tree65d3f936aeb2cb122bc23fcccb19aa571b296fc7 /src/elab_env.sml
parent041a250016b69a70a1fa1ab91ef3c2e61908a9db (diff)
Allow type class instances with hypotheses via local ('let') definitions
Diffstat (limited to 'src/elab_env.sml')
-rw-r--r--src/elab_env.sml165
1 files changed, 93 insertions, 72 deletions
diff --git a/src/elab_env.sml b/src/elab_env.sml
index bf0808f5..df031288 100644
--- a/src/elab_env.sml
+++ b/src/elab_env.sml
@@ -163,6 +163,22 @@ val subExpInExp =
| ((xn, rep), U.Exp.RelC _) => (xn, liftConInExp 0 rep)
| (ctx, _) => ctx}
+val openCon =
+ U.Con.existsB {kind = fn ((nk, _), k) =>
+ case k of
+ KRel n => n >= nk
+ | _ => false,
+ con = fn ((_, nc), c) =>
+ case c of
+ CRel n => n >= nc
+ | _ => false,
+ bind = fn (all as (nk, nc), b) =>
+ case b of
+ U.Con.RelK _ => (nk+1, nc)
+ | U.Con.RelC _ => (nk, nc+1)
+ | _ => all}
+ (0, 0)
+
(* Back to environments *)
datatype 'a var' =
@@ -208,10 +224,12 @@ end
structure CS = BinarySetFn(CK)
structure CM = BinaryMapFn(CK)
-type class = {ground : (con * exp) list,
- rules : (int * con list * con * exp) list}
-val empty_class = {ground = [],
- rules = []}
+type rules = (int * con list * con * exp) list
+
+type class = {closedRules : rules,
+ openRules : rules}
+val empty_class = {closedRules = [],
+ openRules = []}
type env = {
renameK : int SM.map,
@@ -286,11 +304,13 @@ fun pushKRel (env : env) x =
datatypes = #datatypes env,
constructors = #constructors env,
- classes = CM.map (fn cl => {ground = map (fn (c, e) =>
- (liftKindInCon 0 c,
- e))
- (#ground cl),
- rules = #rules cl})
+ classes = CM.map (fn cl => {closedRules = #closedRules cl,
+ openRules = map (fn (nvs, cs, c, e) =>
+ (nvs,
+ map (liftKindInCon 0) cs,
+ liftKindInCon 0 c,
+ liftKindInExp 0 e))
+ (#openRules cl)})
(#classes env),
renameE = SM.map (fn Rel' (n, c) => Rel' (n, liftKindInCon 0 c)
@@ -328,11 +348,13 @@ fun pushCRel (env : env) x k =
constructors = #constructors env,
classes = CM.map (fn class =>
- {ground = map (fn (c, e) =>
- (liftConInCon 0 c,
- e))
- (#ground class),
- rules = #rules class})
+ {closedRules = #closedRules class,
+ openRules = map (fn (nvs, cs, c, e) =>
+ (nvs,
+ map (liftConInCon 0) cs,
+ liftConInCon 0 c,
+ liftConInExp 0 e))
+ (#openRules class)})
(#classes env),
renameE = SM.map (fn Rel' (n, c) => Rel' (n, lift c)
@@ -441,10 +463,9 @@ fun datatypeArgs (xs, _) = xs
fun constructors (_, dt) = IM.foldri (fn (n, (x, to), ls) => (x, n, to) :: ls) [] dt
fun listClasses (env : env) =
- map (fn (cn, {ground, rules}) =>
+ map (fn (cn, {closedRules, openRules}) =>
(class_name_out cn,
- ground
- @ map (fn (nvs, cs, c, e) =>
+ map (fn (nvs, cs, c, e) =>
let
val loc = #2 c
val c = foldr (fn (c', c) => (TFun (c', c), loc)) c cs
@@ -455,7 +476,7 @@ fun listClasses (env : env) =
c (List.tabulate (nvs, fn _ => ()))
in
(c, e)
- end) rules)) (CM.listItemsi (#classes env))
+ end) (closedRules @ openRules))) (CM.listItemsi (#classes env))
fun pushClass (env : env) n =
{renameK = #renameK env,
@@ -653,6 +674,8 @@ fun unifySubst (rs : con list) =
CRel n =>
if n < d then
c
+ else if n - d >= length rs then
+ CRel (n - d)
else
#1 (List.nth (rs, n - d))
| _ => c,
@@ -729,7 +752,7 @@ fun resolveClass (hnorm : con -> con) (consEq : con * con -> bool) (env : env) =
case rules of
[] => notFound ()
| (nRs, cs, c', e) :: rules' =>
- case tryUnify hnorm nRs (c, c') of
+ case tryUnify hnorm nRs (c, c') of
NONE => tryRules rules'
| SOME rs =>
let
@@ -749,18 +772,8 @@ fun resolveClass (hnorm : con -> con) (consEq : con * con -> bool) (env : env) =
SOME e
end
end
-
- fun rules () = tryRules (#rules class)
-
- fun tryGrounds ces =
- case ces of
- [] => rules ()
- | (c', e) :: ces' =>
- case tryUnify hnorm 0 (c, c') of
- NONE => tryGrounds ces'
- | SOME _ => SOME e
in
- tryGrounds (#ground class)
+ tryRules (#openRules class @ #closedRules class)
end
in
if startsWithUnif c then
@@ -800,23 +813,55 @@ fun resolveClass (hnorm : con -> con) (consEq : con * con -> bool) (env : env) =
resolve true
end
+fun rule_in c =
+ let
+ fun quantifiers (c, nvars) =
+ case #1 c of
+ CUnif (_, _, _, _, ref (Known c)) => quantifiers (c, nvars)
+ | TCFun (_, _, _, c) => quantifiers (c, nvars + 1)
+ | _ =>
+ let
+ fun clauses (c, hyps) =
+ case #1 c of
+ TFun (hyp, c) =>
+ (case class_head_in hyp of
+ SOME _ => clauses (c, hyp :: hyps)
+ | NONE => NONE)
+ | _ =>
+ case class_head_in c of
+ NONE => NONE
+ | SOME f => SOME (f, nvars, rev hyps, c)
+ in
+ clauses (c, [])
+ end
+ in
+ quantifiers (c, 0)
+ end
+
fun pushERel (env : env) x t =
let
val renameE = SM.map (fn Rel' (n, t) => Rel' (n+1, t)
| x => x) (#renameE env)
val classes = CM.map (fn class =>
- {ground = map (fn (c, e) => (c, liftExp e)) (#ground class),
- rules = #rules class}) (#classes env)
- val classes = case class_head_in t of
+ {openRules = map (fn (nvs, cs, c, e) => (nvs, cs, c, liftExp e)) (#openRules class),
+ closedRules = #closedRules class}) (#classes env)
+ val classes = case rule_in t of
NONE => classes
- | SOME f =>
+ | SOME (f, nvs, cs, c) =>
case CM.find (classes, f) of
NONE => classes
| SOME class =>
let
- val class = {ground = (t, (ERel 0, #2 t)) :: #ground class,
- rules = #rules class}
+ val rule = (nvs, cs, c, (ERel 0, #2 t))
+
+ val class =
+ if openCon t then
+ {openRules = rule :: #openRules class,
+ closedRules = #closedRules class}
+ else
+ {closedRules = rule :: #closedRules class,
+ openRules = #openRules class}
in
CM.insert (classes, f, class)
end
@@ -848,30 +893,6 @@ fun lookupERel (env : env) n =
(List.nth (#relE env, n))
handle Subscript => raise UnboundRel n
-fun rule_in c =
- let
- fun quantifiers (c, nvars) =
- case #1 c of
- TCFun (_, _, _, c) => quantifiers (c, nvars + 1)
- | _ =>
- let
- fun clauses (c, hyps) =
- case #1 c of
- TFun (hyp, c) =>
- (case class_head_in hyp of
- SOME _ => clauses (c, hyp :: hyps)
- | NONE => NONE)
- | _ =>
- case class_head_in c of
- NONE => NONE
- | SOME f => SOME (f, nvars, rev hyps, c)
- in
- clauses (c, [])
- end
- in
- quantifiers (c, 0)
- end
-
fun pushENamedAs (env : env) x n t =
let
val classes = #classes env
@@ -885,8 +906,8 @@ fun pushENamedAs (env : env) x n t =
val e = (ENamed n, #2 t)
val class =
- {ground = #ground class,
- rules = (nvs, cs, c, e) :: #rules class}
+ {openRules = #openRules class,
+ closedRules = (nvs, cs, c, e) :: #closedRules class}
in
CM.insert (classes, f, class)
end
@@ -1210,11 +1231,11 @@ fun enrichClasses env classes (m1, ms) sgn =
val e = (EModProj (m1, ms, x), #2 sgn)
val class =
- {ground = #ground class,
- rules = (nvs,
- map globalize cs,
- globalize c,
- e) :: #rules class}
+ {openRules = #openRules class,
+ closedRules = (nvs,
+ map globalize cs,
+ globalize c,
+ e) :: #closedRules class}
in
CM.insert (classes, cn, class)
end
@@ -1236,11 +1257,11 @@ fun enrichClasses env classes (m1, ms) sgn =
val e = (EModProj (m1, ms, x), #2 sgn)
val class =
- {ground = #ground class,
- rules = (nvs,
- map globalize cs,
- globalize c,
- e) :: #rules class}
+ {openRules = #openRules class,
+ closedRules = (nvs,
+ map globalize cs,
+ globalize c,
+ e) :: #closedRules class}
in
CM.insert (classes, cn, class)
end