rust/src/rustc/middle/pat_util.rs
Tim Chevalier f39477d926 In resolve, check that an or-pattern has the same number of bindings in each disjunct
resolve3 wasn't checking this. Added test cases. Also added a helpful informational
message in the case where you have a variable binding that you probably think
refers to a variant that you forgot to import.

This is easier to do in resolve than in typeck because there's code in typeck
that assumes that each of the patterns binds the same number of variables.
2012-07-10 18:24:41 -07:00

54 lines
1.4 KiB
Rust

import syntax::ast::*;
import syntax::ast_util;
import syntax::ast_util::{path_to_ident, respan, walk_pat};
import syntax::fold;
import syntax::fold::*;
import syntax::codemap::span;
import std::map::hashmap;
export pat_binding_ids, pat_bindings, pat_id_map;
export pat_is_variant;
type pat_id_map = std::map::hashmap<ident, node_id>;
// This is used because same-named variables in alternative patterns need to
// use the node_id of their namesake in the first pattern.
fn pat_id_map(dm: resolve::def_map, pat: @pat) -> pat_id_map {
let map = std::map::box_str_hash();
do pat_bindings(dm, pat) |p_id, _s, n| {
map.insert(path_to_ident(n), p_id);
};
ret map;
}
fn pat_is_variant(dm: resolve::def_map, pat: @pat) -> bool {
alt pat.node {
pat_enum(_, _) { true }
pat_ident(_, none) {
alt dm.find(pat.id) {
some(def_variant(_, _)) { true }
_ { false }
}
}
_ { false }
}
}
fn pat_bindings(dm: resolve::def_map, pat: @pat,
it: fn(node_id, span, @path)) {
do walk_pat(pat) |p| {
alt p.node {
pat_ident(pth, _) if !pat_is_variant(dm, p) {
it(p.id, p.span, pth);
}
_ {}
}
}
}
fn pat_binding_ids(dm: resolve::def_map, pat: @pat) -> ~[node_id] {
let mut found = ~[];
pat_bindings(dm, pat, |b_id, _sp, _pt| vec::push(found, b_id) );
ret found;
}