106 lines
3.0 KiB
Rust
106 lines
3.0 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use middle::resolve;
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use std::hashmap::HashMap;
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use syntax::ast::*;
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use syntax::ast_util::{path_to_ident, walk_pat};
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use syntax::codemap::Span;
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pub type PatIdMap = HashMap<Ident, NodeId>;
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// This is used because same-named variables in alternative patterns need to
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// use the NodeId of their namesake in the first pattern.
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pub fn pat_id_map(dm: resolve::DefMap, pat: @Pat) -> PatIdMap {
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let mut map = HashMap::new();
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do pat_bindings(dm, pat) |_bm, p_id, _s, n| {
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map.insert(path_to_ident(n), p_id);
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};
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map
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}
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pub fn pat_is_variant_or_struct(dm: resolve::DefMap, pat: &Pat) -> bool {
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match pat.node {
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PatEnum(_, _) | PatIdent(_, _, None) | PatStruct(*) => {
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match dm.find(&pat.id) {
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Some(&DefVariant(*)) | Some(&DefStruct(*)) => 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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pub fn pat_is_const(dm: resolve::DefMap, pat: &Pat) -> bool {
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match pat.node {
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PatIdent(_, _, None) | PatEnum(*) => {
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match dm.find(&pat.id) {
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Some(&DefStatic(_, false)) => 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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pub fn pat_is_binding(dm: resolve::DefMap, pat: @Pat) -> bool {
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match pat.node {
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PatIdent(*) => {
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!pat_is_variant_or_struct(dm, pat) &&
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!pat_is_const(dm, pat)
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}
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_ => false
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}
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}
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pub fn pat_is_binding_or_wild(dm: resolve::DefMap, pat: @Pat) -> bool {
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match pat.node {
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PatIdent(*) => pat_is_binding(dm, pat),
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PatWild => true,
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_ => false
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}
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}
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pub fn pat_bindings(dm: resolve::DefMap, pat: @Pat,
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it: &fn(BindingMode, NodeId, Span, &Path)) {
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do walk_pat(pat) |p| {
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match p.node {
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PatIdent(binding_mode, ref pth, _) if pat_is_binding(dm, p) => {
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it(binding_mode, p.id, p.span, pth);
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}
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_ => {}
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}
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true
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};
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}
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pub fn pat_binding_ids(dm: resolve::DefMap, pat: @Pat) -> ~[NodeId] {
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let mut found = ~[];
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pat_bindings(dm, pat, |_bm, b_id, _sp, _pt| found.push(b_id) );
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return found;
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}
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/// Checks if the pattern contains any patterns that bind something to
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/// an ident, e.g. `foo`, or `Foo(foo)` or `foo @ Bar(*)`.
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pub fn pat_contains_bindings(dm: resolve::DefMap, pat: @Pat) -> bool {
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let mut contains_bindings = false;
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do walk_pat(pat) |p| {
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if pat_is_binding(dm, p) {
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contains_bindings = true;
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false // there's at least one binding, can short circuit now.
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} else {
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true
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}
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};
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contains_bindings
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}
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