user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Typecheck field expressions.

Browse source
This commit is contained in:
Graydon Hoare 2010-11-25 16:40:03 -08:00
parent 092af6fb76
commit 5678f5aa56
1 changed files with 48 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

49
src/comp/middle/typeck.rs
View file

@ -402,6 +402,28 @@ fn last_expr_of_block(&ast.block bloc) -> option.t[@ast.expr] {
}
}
fn field_num(session.session sess, &span sp, &ast.ident id) -> uint {
let uint accum = 0u;
let uint i = 0u;
for (u8 c in id) {
if (i == 0u) {
if (c != '_' as u8) {
sess.span_err(sp, "bad numeric field on tuple");
}
} else {
i += 1u;
if (('0' as u8) <= c && c <= ('9' as u8)) {
accum *= 10u;
accum += (c as uint) - ('0' as uint);
} else {
sess.span_err(sp, "bad numeric field on tuple");
}
}
}
ret accum;
}
// Type utilities
// FIXME: remove me when == works on these tags.
@ -792,7 +814,6 @@ fn unify(&fn_ctxt fcx, @ty expected, @ty actual) -> unify_result {
auto result = unify_step(fcx, bindings, expected_ty, actual);
alt (result) {
case (ures_ok(?result_ty)) {
fcx.locals.insert(expected_id, result_ty);
}
case (_) { /* empty */ }
@ -1215,7 +1236,33 @@ fn check_expr(&fn_ctxt fcx, @ast.expr expr) -> @ast.expr {
ast.expr_tup(args_1, ann));
}
case (ast.expr_field(?base, ?field, _)) {
auto base_1 = check_expr(fcx, base);
auto base_t = expr_ty(base_1);
alt (base_t.struct) {
case (ty_tup(?args)) {
let uint ix = field_num(fcx.ccx.sess,
expr.span, field);
if (ix >= _vec.len[tup(bool,@ty)](args)) {
fcx.ccx.sess.span_err(expr.span,
"bad index on tuple");
}
auto ann = ast.ann_type(args.(ix)._1);
ret @fold.respan[ast.expr_](expr.span,
ast.expr_field(base_1,
field,
ann));
}
case (_) {
fcx.ccx.sess.unimpl("base type for expr_field "
+ "in typeck.check_expr: "
+ ty_to_str(base_t));
}
}
}
case (_) {
fcx.ccx.sess.unimpl("expr type in typeck.check_expr");
// TODO
ret expr;
}