diff --git a/interp.js b/interp.js
index 1277525d0ae0663d910bcaac543c43062ffc4b73..cf589e87bbfff7a2e04c6f053a7ad5c5965230f1 100644
--- a/interp.js
+++ b/interp.js
@@ -13,15 +13,16 @@
trm_var => "name"
trm_cst => "cst"
trm_let => "name", "t1", "t2"
- trm_read => "loc"
- trm_write => "loc", "arg"
-
+ trm_get => "loc" "field"
+ trm_set => "loc", "field", "arg"
+ trm_if => "cond", "then", "else_option"
Encoding of Caml algebraic data types into objects
cst_number 5 => { type: "cst", tag: "cst_number", val: 5 }
val_abs(e,r,p,t) => { type: "val", tag: "val_abs",
env:e, recname:r, pattern:p, body:t }
+ special case for option: undefined
*/
/*
@@ -80,11 +81,9 @@
| trm_app of trm * trm
| trm_seq of trm * trm
| trm_let of pat * trm * trm
- | trm_alloc of trm
- | trm_read of trm
- | trm_write of trm * trm
- | trm_get of trm * lab
- | trm_set of trm * lab * trm
+ | trm_alloc
+ | trm_get of trm * field_name
+ | trm_set of trm * field_name * trm
| trm_if of trm * trm * option trm
| trm_match of trm * array<branch>
| trm_abort
@@ -104,7 +103,7 @@
function stuck(msg) {
- throw { type: "stuck", msg: msg };
+ throw { type: "stuck", msg: msg };
}
// all monads have return type "res"
@@ -155,8 +154,8 @@ function if_success_bool_cases(res, K1, K2) {
// types heap and env have special treatment: they are updated by side effects
-var heap = []
-var env = { tag: "env_nil" }
+var heap = [];
+var env = { tag: "env_nil" };
function lookup_var(x) {
var e = env;
@@ -174,23 +173,29 @@ function res_val(v) {
}
-function heap_alloc(arg) {
+function heap_alloc() {
var loc = heap.length;
- heap[loc] = arg;
+ heap[loc] = {};
return loc;
}
-function heap_write(loc, arg) {
- heap[loc] = arg;
-}
-
-function heap_read(loc) {
- var v = heap[loc.loc];
- if (v === undefined)
+// loc has type value (with a loc field), field is a string
+function heap_get(loc, field) {
+ var obj = heap[loc.loc];
+ if (obj === undefined)
stuck("unbound loc " + loc);
+ var v = obj[field];
+ if (v === undefined)
+ stuck("unbound field " + field + " in loc " + loc);
return v;
}
+function heap_set(loc, field, arg) {
+ var obj = heap[loc.loc];
+ if (obj === undefined)
+ stuck("unbound loc " + loc);
+ obj[field] = arg;
+}
function env_pop() {
if (env.tag !== "env_cons")
@@ -202,48 +207,62 @@ function env_push(x, v) {
env = { tag: "env_cons", env: env, name: x, val: v };
}
-
function run_trm(t) {
switch (t.tag) {
- case "trm_var":
- var v = lookup_var(t.name);
+ case "trm_var":
+ var v = lookup_var(t.name);
+ return res_val(v);
+ case "trm_cst":
+ return res_val({ tag: "val_cst", cst: t.cst });
+ case "trm_let":
+ return if_success(run_trm(t.t1), function(v1) {
+ env_push(t.name, v1);
+ var res = run_trm(t.t2);
+ env_pop();
+ return res;
+ });
+ case "trm_seq":
+ return if_success(run_trm(t.t1), function(v1) {
+ return run_trm(t.t2);
+ });
+ case "trm_alloc":
+ var loc = heap_alloc();
+ return res_val({ tag: "val_loc", loc: loc });
+ case "trm_get":
+ return if_success(run_trm(t.loc), function(loc) {
+ var v = heap_get(loc, t.field);
return res_val(v);
- case "trm_cst":
- return res_val({ tag: "val_cst", cst: t.cst });
- case "trm_let":
- return if_success(run_trm(t.t1), function(v1) {
- env_push(t.name, v1);
- var res = run_trm(t.t2);
- env_pop();
- return res;
- });
- case "trm_alloc":
+ });
+ case "trm_set":
+ return if_success(run_trm(t.loc), function(loc) {
return if_success(run_trm(t.arg), function(arg) {
- var loc = heap_alloc(arg);
- return res_val({ tag: "val_loc", loc: loc });
+ heap_set(loc, t.field, arg);
+ return res_val(arg);
});
- case "trm_read":
- return if_success(run_trm(t.loc), function(loc) {
- var v = heap_read(loc);
- return res_val(v);
- });
- case "trm_write":
- return if_success(run_trm(t.loc), function(loc) {
- return if_success(run_trm(t.arg), function(arg) {
- heap_write(loc, arg);
- return res_val({ tag: "val_bool", bool: true });
- });
+ });
+ case "trm_if":
+ return if_success(run_trm(t.cond), function(cond) {
+ return if_bool(cond, function(b) {
+ if (b) {
+ return run_trm(t.then);
+ } else if (t.else_option !== undefined) {
+ return run_trm(t.else);
+ } else {
+ // res_unit
+ return res_val({tag:"val_cst", cst:{tag:"cst_bool", bool:true}});
+ }
});
- default:
- stuck("invalid trm tag");
+ });
+ default:
+ stuck("invalid trm tag");
}
}
-function run_program(program) {
- for (var i = 0; i < program.length; i++) {
- run_trm(program[i]);
+ function run_program(program) {
+ for (var i = 0; i < program.length; i++) {
+ run_trm(program[i]);
+ }
}
-}
@@ -255,124 +274,125 @@ function trm_let(name, t1, t2) {
return { tag: "trm_let", name: name, t1: t1, t2: t2 };
}
+function trm_seq(t1, t2) {
+ return { tag: "trm_seq", t1: t1, t2: t2 };
+}
+
function trm_var(name) {
return { tag: "trm_var", name: name };
}
-var trm1 =
- trm_let("x", { tag: "trm_alloc", arg: trm_number(1) },
- trm_let("y", { tag: "trm_alloc", arg:
- { tag: "trm_read", loc: trm_var("x") }
- },
- trm_let("z", { tag: "trm_alloc", arg: trm_var("x") },
- trm_let("t", { tag: "trm_write", loc: trm_var("x"), arg: trm_var("z") },
- trm_number(0)))));
+var trm1 =
+ trm_let("x", { tag: "trm_alloc"},
+ trm_seq(trm_seq({tag: "trm_set", loc: trm_var("x"), field: "foo", arg: trm_number(12)},
+ {tag: "trm_set", loc: trm_var("x"), field: "bar",
+ arg: {tag:"trm_get", loc: trm_var("x"), field: "foo"}}),
+ {tag: "trm_set", loc: trm_var("x"), field: "cycle",
+ arg: trm_var("x")}));
var program = [trm1];
run_program(program);
+ /*
+ Definition run_trm R m t : result :=
+ let run_trm := runs_trm R in
+ match t with
+ | trm_var x => res_stuck
+ | trm_cst c => out_ter m c
+ | trm_abs oy p t1 =>
+ out_ter m (val_abs oy p t1)
+ | trm_constr k ts =>
+ runs_list R m ts nil (fun m vs =>
+ out_ter m (val_constr k vs))
+ | trm_record ats => res_unimplem
+ | trm_unary f t1 =>
+ if_success (run_trm m t1) (fun m v1 =>
+ let ret v := out_ter m v in
+ match f with
+ | prim_neg => if_bool v1 (fun z => ret (neg z))
+ | prim_not => if_int v1 (fun n => ret (-n))
+ | _ => stuck "invalid unary operator"
+ end)
+ | trm_binary f t1 t2 =>
+ if_success (run_trm m t1) (fun m v1 =>
+ if_success (run_trm m t2) (fun m v2 =>
+ let ret v := out_ter m v in
+ let op_int F :=
+ if_int v1 (fun n1 => if_int v2 (fun n2 => F n1 n2)) in
+ match f with
+ | prim_eq => run_primitive_eq m v1 v2
+ | prim_add => op_int (fun n1 n2 => ret (n1+n2))
+ | _ => stuck "invalid binary operator"
+ end))
+ | trm_app t1 t2 =>
+ if_success (run_trm m t1) (fun m v1 =>
+ if_success (run_trm m t2) (fun m v2 =>
+ if_abs v1 (fun oy p t =>
+ run_call R m oy p t v2)))
+ | trm_seq t1 t2 =>
+ if_success (run_trm m t1) (fun m v1 =>
+ If v1 = val_unit
+ then (run_trm m t2)
+ else stuck "sequence with LHS that is not unit")
+ | trm_if t1 t2 t3o =>
+ if_success_bool_cases (run_trm m t1)
+ (fun m => run_trm m t2)
+ (fun m =>
+ match t3o with
+ | None => out_ter m val_unit
+ | Some t3 => run_trm m t3
+ end)
+ | trm_match t1 bs =>
+ if_success (run_trm m t1) (fun m v1 =>
+ let B := (beh_exn constr_matching_failure) in
+ runs_branches R m B v1 bs)
+ | trm_abort
+ */
+
+
+ function jsheap_of_heap(heap) {
+ var jsheap = [];
+ var i;
+
+ for (i = 0; i < heap.length; i++) {
+ jsheap[i] = {};
+ }
-
-/*
-Definition run_trm R m t : result :=
- let run_trm := runs_trm R in
- match t with
- | trm_var x => res_stuck
- | trm_cst c => out_ter m c
- | trm_abs oy p t1 =>
- out_ter m (val_abs oy p t1)
- | trm_constr k ts =>
- runs_list R m ts nil (fun m vs =>
- out_ter m (val_constr k vs))
- | trm_record ats => res_unimplem
- | trm_unary f t1 =>
- if_success (run_trm m t1) (fun m v1 =>
- let ret v := out_ter m v in
- match f with
- | prim_neg => if_bool v1 (fun z => ret (neg z))
- | prim_not => if_int v1 (fun n => ret (-n))
- | _ => stuck "invalid unary operator"
- end)
- | trm_binary f t1 t2 =>
- if_success (run_trm m t1) (fun m v1 =>
- if_success (run_trm m t2) (fun m v2 =>
- let ret v := out_ter m v in
- let op_int F :=
- if_int v1 (fun n1 => if_int v2 (fun n2 => F n1 n2)) in
- match f with
- | prim_eq => run_primitive_eq m v1 v2
- | prim_add => op_int (fun n1 n2 => ret (n1+n2))
- | _ => stuck "invalid binary operator"
- end))
- | trm_app t1 t2 =>
- if_success (run_trm m t1) (fun m v1 =>
- if_success (run_trm m t2) (fun m v2 =>
- if_abs v1 (fun oy p t =>
- run_call R m oy p t v2)))
- | trm_seq t1 t2 =>
- if_success (run_trm m t1) (fun m v1 =>
- If v1 = val_unit
- then (run_trm m t2)
- else stuck "sequence with LHS that is not unit")
- | trm_if t1 t2 t3o =>
- if_success_bool_cases (run_trm m t1)
- (fun m => run_trm m t2)
- (fun m =>
- match t3o with
- | None => out_ter m val_unit
- | Some t3 => run_trm m t3
- end)
- | trm_match t1 bs =>
- if_success (run_trm m t1) (fun m v1 =>
- let B := (beh_exn constr_matching_failure) in
- runs_branches R m B v1 bs)
- | trm_abort
-*/
-
-
-function jsheap_of_heap(heap) {
- var jsheap = []
-
- for (var i = 0; i < heap.length; i++) {
- jsheap[i] = {}
- }
-
- for (var i = 0; i < heap.length; i++) {
- var obj = jsvalue_of_value(jsheap, heap[i])
- if (typeof obj === "object") {
- Object.defineProperties(jsheap[i], obj)
- } else {
- jsheap[i] = obj
+ for (i = 0; i < heap.length; i++) {
+ for (var x in heap[i]) {
+ jsheap[i][x] = jsvalue_of_value(jsheap, heap[i][x]);
+ }
}
- }
- return jsheap
+ return jsheap;
}
function jsvalue_of_cst(c) {
switch (c.tag) {
- case "cst_bool":
- return c.bool
- case "cst_number":
- return c.number
+ case "cst_bool":
+ return c.bool;
+ case "cst_number":
+ return c.number;
+ default:
+ stuck("unrecognized cst");
}
}
function jsvalue_of_value(jsheap, v) {
switch (v.tag) {
- case "val_cst":
- return jsvalue_of_cst(v.cst)
- case "val_loc":
- return jsheap[v.loc]
- case "val_abs":
- return "<closure>"
+ case "val_cst":
+ return jsvalue_of_cst(v.cst);
+ case "val_loc":
+ return jsheap[v.loc];
+ case "val_abs":
+ return "<closure>";
// case "val_constr":
// case "val_record":
- default:
- stuck("unrecognised value")
+ default:
+ stuck("unrecognized value");
}
}
diff --git a/test.html b/test.html
index 8ff5bb3776e4047f6e8d3887e8d857710121f28d..b405dadcb406b2c1dd50f2872d55e58be02a0dbb 100644
--- a/test.html
+++ b/test.html
@@ -1,7 +1,17 @@
<!DOCTYPE html>
<html>
<body>
-<script src="sparray.js"></script>
+ <pre>
+ var trm1 =
+ trm_let("x", { tag: "trm_alloc"},
+ trm_seq(trm_seq({tag: "trm_set", loc: trm_var("x"), field: "foo", arg: trm_number(12)},
+ {tag: "trm_set", loc: trm_var("x"), field: "bar",
+ arg: {tag:"trm_get", loc: trm_var("x"), field: "foo"}}),
+ {tag: "trm_set", loc: trm_var("x"), field: "cycle",
+ arg: trm_var("x")}));
+</pre>
+ <script src="sparray.js"></script>
+<script src="interp.js"></script>
</body>
</html>