rustc: Factor out path type instantiation so that tag patterns can use it as well

This commit is contained in:
Patrick Walton 2011-03-08 18:48:17 -08:00
parent e64085b0a2
commit 0a22a4edbb

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@ -128,6 +128,112 @@ fn substitute_ty_params(&@crate_ctxt ccx,
ret ty.fold_ty(substituter, typ);
}
// Instantiates the given path, which must refer to an item with the given
// definition.
fn instantiate_path(@fn_ctxt fcx, &ast.path pth, &ast.def defn, &span sp)
-> ast.ann {
auto t;
auto ty_params;
alt (defn) {
case (ast.def_arg(?id)) {
check (fcx.locals.contains_key(id));
t = fcx.locals.get(id);
ty_params = none[vec[ast.def_id]];
}
case (ast.def_local(?id)) {
alt (fcx.locals.find(id)) {
case (some[@ty.t](?t1)) { t = t1; }
case (none[@ty.t]) { t = plain_ty(ty.ty_local(id)); }
}
ty_params = none[vec[ast.def_id]];
}
case (ast.def_obj_field(?id)) {
check (fcx.locals.contains_key(id));
t = fcx.locals.get(id);
ty_params = none[vec[ast.def_id]];
}
case (ast.def_fn(?id)) {
check (fcx.ccx.item_types.contains_key(id));
t = fcx.ccx.item_types.get(id);
ty_params = some(fcx.ccx.item_ty_params.get(id));
}
case (ast.def_native_fn(?id)) {
check (fcx.ccx.item_types.contains_key(id));
t = fcx.ccx.item_types.get(id);
ty_params = some(fcx.ccx.item_ty_params.get(id));
}
case (ast.def_const(?id)) {
check (fcx.ccx.item_types.contains_key(id));
t = fcx.ccx.item_types.get(id);
ty_params = none[vec[ast.def_id]];
}
case (ast.def_variant(?tag_id, ?variant_id)) {
check (fcx.ccx.item_types.contains_key(variant_id));
t = fcx.ccx.item_types.get(variant_id);
ty_params = some(fcx.ccx.item_ty_params.get(tag_id));
}
case (ast.def_binding(?id)) {
check (fcx.locals.contains_key(id));
t = fcx.locals.get(id);
ty_params = none[vec[ast.def_id]];
}
case (ast.def_obj(?id)) {
check (fcx.ccx.item_types.contains_key(id));
t = fcx.ccx.item_types.get(id);
ty_params = some(fcx.ccx.item_ty_params.get(id));
}
case (ast.def_mod(_)) {
// Hopefully part of a path.
t = plain_ty(ty.ty_nil); // TODO: something more poisonous?
ty_params = none[vec[ast.def_id]];
}
case (_) {
// FIXME: handle other names.
fcx.ccx.sess.unimpl("definition variant for: "
+ _str.connect(pth.node.idents, "."));
fail;
}
}
auto ty_substs_opt;
auto ty_substs_len = _vec.len[@ast.ty](pth.node.types);
if (ty_substs_len > 0u) {
let vec[@ty.t] ty_substs = vec();
auto i = 0u;
while (i < ty_substs_len) {
ty_substs += vec(ast_ty_to_ty_crate(fcx.ccx, pth.node.types.(i)));
i += 1u;
}
ty_substs_opt = some[vec[@ty.t]](ty_substs);
alt (ty_params) {
case (none[vec[ast.def_id]]) {
fcx.ccx.sess.span_err(sp, "this kind of item may not take " +
"type parameters");
fail;
}
case (some[vec[ast.def_id]](?tps)) {
t = substitute_ty_params(fcx.ccx, t, tps, ty_substs, sp);
}
}
} else {
ty_substs_opt = none[vec[@ty.t]];
alt (ty_params) {
case (none[vec[ast.def_id]]) { /* nothing */ }
case (some[vec[ast.def_id]](_)) {
// We will acquire the type parameters through
// unification.
t = generalize_ty(fcx.ccx, t);
}
}
}
ret ast.ann_type(t, ty_substs_opt);
}
// Returns the type parameters and polytype of an item, if it's an item that
// supports type parameters.
fn ty_params_for_item(@crate_ctxt ccx, &ast.def d)
@ -1561,109 +1667,8 @@ fn check_expr(&@fn_ctxt fcx, @ast.expr expr) -> @ast.expr {
case (ast.expr_path(?pth, ?defopt, _)) {
auto t = plain_ty(ty.ty_nil);
check (defopt != none[ast.def]);
auto ty_params;
alt (option.get[ast.def](defopt)) {
case (ast.def_arg(?id)) {
check (fcx.locals.contains_key(id));
t = fcx.locals.get(id);
ty_params = none[vec[ast.def_id]];
}
case (ast.def_local(?id)) {
alt (fcx.locals.find(id)) {
case (some[@ty.t](?t1)) { t = t1; }
case (none[@ty.t]) { t = plain_ty(ty.ty_local(id)); }
}
ty_params = none[vec[ast.def_id]];
}
case (ast.def_obj_field(?id)) {
check (fcx.locals.contains_key(id));
t = fcx.locals.get(id);
ty_params = none[vec[ast.def_id]];
}
case (ast.def_fn(?id)) {
check (fcx.ccx.item_types.contains_key(id));
t = fcx.ccx.item_types.get(id);
ty_params = some(fcx.ccx.item_ty_params.get(id));
}
case (ast.def_native_fn(?id)) {
check (fcx.ccx.item_types.contains_key(id));
t = fcx.ccx.item_types.get(id);
ty_params = some(fcx.ccx.item_ty_params.get(id));
}
case (ast.def_const(?id)) {
check (fcx.ccx.item_types.contains_key(id));
t = fcx.ccx.item_types.get(id);
ty_params = none[vec[ast.def_id]];
}
case (ast.def_variant(?tag_id, ?variant_id)) {
check (fcx.ccx.item_types.contains_key(variant_id));
t = fcx.ccx.item_types.get(variant_id);
ty_params = some(fcx.ccx.item_ty_params.get(tag_id));
}
case (ast.def_binding(?id)) {
check (fcx.locals.contains_key(id));
t = fcx.locals.get(id);
ty_params = none[vec[ast.def_id]];
}
case (ast.def_obj(?id)) {
check (fcx.ccx.item_types.contains_key(id));
t = fcx.ccx.item_types.get(id);
ty_params = some(fcx.ccx.item_ty_params.get(id));
}
case (ast.def_mod(_)) {
// Hopefully part of a path.
ty_params = none[vec[ast.def_id]];
}
case (_) {
// FIXME: handle other names.
fcx.ccx.sess.unimpl("definition variant for: "
+ _str.connect(pth.node.idents, "."));
fail;
}
}
// Substitute type parameters if the user provided some.
auto ty_substs_opt;
auto ty_substs_len = _vec.len[@ast.ty](pth.node.types);
if (ty_substs_len > 0u) {
let vec[@ty.t] ty_substs = vec();
auto i = 0u;
while (i < ty_substs_len) {
ty_substs += vec(ast_ty_to_ty_crate(fcx.ccx,
pth.node.types.(i)));
i += 1u;
}
ty_substs_opt = some[vec[@ty.t]](ty_substs);
alt (ty_params) {
case (none[vec[ast.def_id]]) {
fcx.ccx.sess.span_err(expr.span, "this kind of " +
"item may not take type " +
"parameters");
fail;
}
case (some[vec[ast.def_id]](?tps)) {
t = substitute_ty_params(fcx.ccx, t, tps, ty_substs,
expr.span);
}
}
} else {
ty_substs_opt = none[vec[@ty.t]];
alt (ty_params) {
case (none[vec[ast.def_id]]) { /* nothing */ }
case (some[vec[ast.def_id]](_)) {
// We will acquire the type parameters through
// unification.
t = generalize_ty(fcx.ccx, t);
}
}
}
auto ann = ast.ann_type(t, ty_substs_opt);
auto defn = option.get[ast.def](defopt);
auto ann = instantiate_path(fcx, pth, defn, expr.span);
ret @fold.respan[ast.expr_](expr.span,
ast.expr_path(pth, defopt, ann));
}