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Remove type coercion from fn to block

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fn is a proper subtype of block now
This commit is contained in:
Brian Anderson 2011-10-14 18:32:07 -07:00
parent 8136b92ee8
commit 342a400e79
1 changed files with 4 additions and 48 deletions
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52
src/comp/middle/typeck.rs
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@ -891,43 +891,6 @@ fn do_autoderef(fcx: @fn_ctxt, sp: span, t: ty::t) -> ty::t {
fail;
}
fn do_fn_ty_coerce(fcx: @fn_ctxt, sp: span, actual: ty::t, expected: ty::t)
-> ty::t {
// fns can be silently coerced to blocks when being used as
// function call or bind arguments, but not the reverse.
// If our actual type is a fn and our expected type is a block,
// build up a new expected type that is identical to the old one
// except for its proto. If we don't know the expected or actual
// types, that's fine, but we can't do the coercion.
ret alt structure_of_maybe(fcx, sp, actual) {
some(ty::ty_fn(ast::proto_fn., args, ret_ty, cf, constrs)) {
alt structure_of_maybe(fcx, sp, expected) {
some(ty::ty_fn(ast::proto_block., _, _, _, _)) {
ty::mk_fn(fcx.ccx.tcx, ast::proto_block, args, ret_ty, cf,
constrs)
}
_ { actual }
}
}
some(ty::ty_fn(ast::proto_bare., args, ret_ty, cf, constrs)) {
alt structure_of_maybe(fcx, sp, expected) {
some(ty::ty_fn(ast::proto_fn., _, _, _, _)) {
ty::mk_fn(fcx.ccx.tcx, ast::proto_fn, args, ret_ty, cf,
constrs)
}
some(ty::ty_fn(ast::proto_block., _, _, _, _)) {
ty::mk_fn(fcx.ccx.tcx, ast::proto_block, args, ret_ty, cf,
constrs)
}
_ { actual }
}
}
_ { actual }
}
}
fn resolve_type_vars_if_possible(fcx: @fn_ctxt, typ: ty::t) -> ty::t {
alt ty::unify::fixup_vars(fcx.ccx.tcx, none, fcx.var_bindings, typ) {
fix_ok(new_type) { ret new_type; }
@ -943,26 +906,19 @@ type ty_param_substs_and_ty = {substs: [ty::t], ty: ty::t};
mod demand {
fn simple(fcx: @fn_ctxt, sp: span, expected: ty::t, actual: ty::t) ->
ty::t {
full(fcx, sp, expected, actual, [], false).ty
}
fn fn_coerce(fcx: @fn_ctxt, sp: span, expected: ty::t, actual: ty::t)
-> ty::t {
full(fcx, sp, expected, actual, [], true).ty
full(fcx, sp, expected, actual, []).ty
}
fn with_substs(fcx: @fn_ctxt, sp: span, expected: ty::t, actual: ty::t,
ty_param_substs_0: [ty::t]) -> ty_param_substs_and_ty {
full(fcx, sp, expected, actual, ty_param_substs_0, false)
full(fcx, sp, expected, actual, ty_param_substs_0)
}
// Requires that the two types unify, and prints an error message if they
// don't. Returns the unified type and the type parameter substitutions.
fn full(fcx: @fn_ctxt, sp: span, expected: ty::t, actual: ty::t,
ty_param_substs_0: [ty::t], do_fn_coerce: bool) ->
ty_param_substs_0: [ty::t]) ->
ty_param_substs_and_ty {
if do_fn_coerce {
actual = do_fn_ty_coerce(fcx, sp, actual, expected);
}
let ty_param_substs: [mutable ty::t] = [mutable];
let ty_param_subst_var_ids: [int] = [];
@ -1689,7 +1645,7 @@ fn check_expr_with_unifier(fcx: @fn_ctxt, expr: @ast::expr, unify: unifier,
if is_block == check_blocks {
bot |=
check_expr_with_unifier(fcx, a,
demand::fn_coerce,
demand::simple,
arg_tys[i].ty);
}
}