133 lines
3.8 KiB
Rust
133 lines
3.8 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
|
|
// file at the top-level directory of this distribution and at
|
|
// http://rust-lang.org/COPYRIGHT.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
|
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
|
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
|
// option. This file may not be copied, modified, or distributed
|
|
// except according to those terms.
|
|
|
|
use middle::def::*;
|
|
use middle::resolve;
|
|
use middle::ty;
|
|
|
|
use std::collections::HashMap;
|
|
use std::gc::{Gc, GC};
|
|
use syntax::ast::*;
|
|
use syntax::ast_util::{walk_pat};
|
|
use syntax::codemap::{Span, DUMMY_SP};
|
|
use syntax::owned_slice::OwnedSlice;
|
|
|
|
pub type PatIdMap = HashMap<Ident, NodeId>;
|
|
|
|
// This is used because same-named variables in alternative patterns need to
|
|
// use the NodeId of their namesake in the first pattern.
|
|
pub fn pat_id_map(dm: &resolve::DefMap, pat: &Pat) -> PatIdMap {
|
|
let mut map = HashMap::new();
|
|
pat_bindings(dm, pat, |_bm, p_id, _s, path1| {
|
|
map.insert(path1.node, p_id);
|
|
});
|
|
map
|
|
}
|
|
|
|
pub fn pat_is_variant_or_struct(dm: &resolve::DefMap, pat: &Pat) -> bool {
|
|
match pat.node {
|
|
PatEnum(_, _) | PatIdent(_, _, None) | PatStruct(..) => {
|
|
match dm.borrow().find(&pat.id) {
|
|
Some(&DefVariant(..)) | Some(&DefStruct(..)) => true,
|
|
_ => false
|
|
}
|
|
}
|
|
_ => false
|
|
}
|
|
}
|
|
|
|
pub fn pat_is_const(dm: &resolve::DefMap, pat: &Pat) -> bool {
|
|
match pat.node {
|
|
PatIdent(_, _, None) | PatEnum(..) => {
|
|
match dm.borrow().find(&pat.id) {
|
|
Some(&DefStatic(_, false)) => true,
|
|
_ => false
|
|
}
|
|
}
|
|
_ => false
|
|
}
|
|
}
|
|
|
|
pub fn pat_is_binding(dm: &resolve::DefMap, pat: &Pat) -> bool {
|
|
match pat.node {
|
|
PatIdent(..) => {
|
|
!pat_is_variant_or_struct(dm, pat) &&
|
|
!pat_is_const(dm, pat)
|
|
}
|
|
_ => false
|
|
}
|
|
}
|
|
|
|
pub fn pat_is_binding_or_wild(dm: &resolve::DefMap, pat: &Pat) -> bool {
|
|
match pat.node {
|
|
PatIdent(..) => pat_is_binding(dm, pat),
|
|
PatWild(_) => true,
|
|
_ => false
|
|
}
|
|
}
|
|
|
|
/// Call `it` on every "binding" in a pattern, e.g., on `a` in
|
|
/// `match foo() { Some(a) => (), None => () }`
|
|
pub fn pat_bindings(dm: &resolve::DefMap,
|
|
pat: &Pat,
|
|
it: |BindingMode, NodeId, Span, &SpannedIdent|) {
|
|
walk_pat(pat, |p| {
|
|
match p.node {
|
|
PatIdent(binding_mode, ref pth, _) if pat_is_binding(dm, p) => {
|
|
it(binding_mode, p.id, p.span, pth);
|
|
}
|
|
_ => {}
|
|
}
|
|
true
|
|
});
|
|
}
|
|
|
|
/// Checks if the pattern contains any patterns that bind something to
|
|
/// an ident, e.g. `foo`, or `Foo(foo)` or `foo @ Bar(..)`.
|
|
pub fn pat_contains_bindings(dm: &resolve::DefMap, pat: &Pat) -> bool {
|
|
let mut contains_bindings = false;
|
|
walk_pat(pat, |p| {
|
|
if pat_is_binding(dm, p) {
|
|
contains_bindings = true;
|
|
false // there's at least one binding, can short circuit now.
|
|
} else {
|
|
true
|
|
}
|
|
});
|
|
contains_bindings
|
|
}
|
|
|
|
pub fn simple_identifier<'a>(pat: &'a Pat) -> Option<&'a Ident> {
|
|
match pat.node {
|
|
PatIdent(BindByValue(_), ref path1, None) => {
|
|
Some(&path1.node)
|
|
}
|
|
_ => {
|
|
None
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn wild() -> Gc<Pat> {
|
|
box (GC) Pat { id: 0, node: PatWild(PatWildSingle), span: DUMMY_SP }
|
|
}
|
|
|
|
pub fn def_to_path(tcx: &ty::ctxt, id: DefId) -> Path {
|
|
ty::with_path(tcx, id, |mut path| Path {
|
|
global: false,
|
|
segments: path.last().map(|elem| PathSegment {
|
|
identifier: Ident::new(elem.name()),
|
|
lifetimes: vec!(),
|
|
types: OwnedSlice::empty()
|
|
}).move_iter().collect(),
|
|
span: DUMMY_SP,
|
|
})
|
|
}
|