57 lines
1.6 KiB
Rust
57 lines
1.6 KiB
Rust
import syntax::ast::*;
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import syntax::ast_util;
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import syntax::ast_util::{path_to_ident, respan, walk_pat};
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import syntax::fold;
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import syntax::fold::*;
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import syntax::codemap::span;
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import std::map::hashmap;
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export pat_binding_ids, pat_bindings, pat_id_map;
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export pat_is_variant;
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type pat_id_map = std::map::hashmap<str, node_id>;
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// This is used because same-named variables in alternative patterns need to
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// use the node_id of their namesake in the first pattern.
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fn pat_id_map(dm: resolve::def_map, pat: @pat) -> pat_id_map {
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let map = std::map::str_hash();
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pat_bindings(dm, pat) {|p_id, _s, n|
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map.insert(path_to_ident(n), p_id);
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};
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ret map;
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}
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fn pat_is_variant(dm: resolve::def_map, pat: @pat) -> bool {
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alt pat.node {
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pat_enum(_, _) { true }
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pat_ident(_, none) {
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alt dm.find(pat.id) {
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some(def_variant(_, _)) { true }
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_ { false }
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}
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}
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_ { false }
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}
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}
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// This does *not* normalize. The pattern should be already normalized
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// if you want to get a normalized pattern out of it.
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// Could return a constrained type in order to express that (future work)
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fn pat_bindings(dm: resolve::def_map, pat: @pat,
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it: fn(node_id, span, @path)) {
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walk_pat(pat) {|p|
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alt p.node {
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pat_ident(pth, _) if !pat_is_variant(dm, p) {
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it(p.id, p.span, pth);
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}
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_ {}
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}
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}
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}
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fn pat_binding_ids(dm: resolve::def_map, pat: @pat) -> [node_id] {
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let mut found = [];
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pat_bindings(dm, pat) {|b_id, _sp, _pt| found += [b_id]; };
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ret found;
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}
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