rust/crates/ra_hir_def/src/item_scope.rs

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2019-12-20 08:43:45 -06:00
use hir_expand::name::Name;
use once_cell::sync::Lazy;
use rustc_hash::FxHashMap;
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use crate::{per_ns::PerNs, BuiltinType, LocalImportId, MacroDefId, ModuleDefId, TraitId};
#[derive(Debug, Default, PartialEq, Eq)]
pub struct ModuleScope {
pub(crate) items: FxHashMap<Name, Resolution>,
/// Macros visable in current module in legacy textual scope
///
/// For macros invoked by an unquatified identifier like `bar!()`, `legacy_macros` will be searched in first.
/// If it yields no result, then it turns to module scoped `macros`.
/// It macros with name quatified with a path like `crate::foo::bar!()`, `legacy_macros` will be skipped,
/// and only normal scoped `macros` will be searched in.
///
/// Note that this automatically inherit macros defined textually before the definition of module itself.
///
/// Module scoped macros will be inserted into `items` instead of here.
// FIXME: Macro shadowing in one module is not properly handled. Non-item place macros will
// be all resolved to the last one defined if shadowing happens.
pub(crate) legacy_macros: FxHashMap<Name, MacroDefId>,
}
static BUILTIN_SCOPE: Lazy<FxHashMap<Name, Resolution>> = Lazy::new(|| {
BuiltinType::ALL
.iter()
.map(|(name, ty)| {
(name.clone(), Resolution { def: PerNs::types(ty.clone().into()), import: None })
})
.collect()
});
/// Shadow mode for builtin type which can be shadowed by module.
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub enum BuiltinShadowMode {
// Prefer Module
Module,
// Prefer Other Types
Other,
}
/// Legacy macros can only be accessed through special methods like `get_legacy_macros`.
/// Other methods will only resolve values, types and module scoped macros only.
impl ModuleScope {
pub fn entries<'a>(&'a self) -> impl Iterator<Item = (&'a Name, &'a Resolution)> + 'a {
//FIXME: shadowing
self.items.iter().chain(BUILTIN_SCOPE.iter())
}
pub fn declarations(&self) -> impl Iterator<Item = ModuleDefId> + '_ {
self.entries()
.filter_map(|(_name, res)| if res.import.is_none() { Some(res.def) } else { None })
.flat_map(|per_ns| {
per_ns.take_types().into_iter().chain(per_ns.take_values().into_iter())
})
}
/// Iterate over all module scoped macros
pub fn macros<'a>(&'a self) -> impl Iterator<Item = (&'a Name, MacroDefId)> + 'a {
self.items
.iter()
.filter_map(|(name, res)| res.def.take_macros().map(|macro_| (name, macro_)))
}
/// Iterate over all legacy textual scoped macros visable at the end of the module
pub fn legacy_macros<'a>(&'a self) -> impl Iterator<Item = (&'a Name, MacroDefId)> + 'a {
self.legacy_macros.iter().map(|(name, def)| (name, *def))
}
/// Get a name from current module scope, legacy macros are not included
pub fn get(&self, name: &Name, shadow: BuiltinShadowMode) -> Option<&Resolution> {
match shadow {
BuiltinShadowMode::Module => self.items.get(name).or_else(|| BUILTIN_SCOPE.get(name)),
BuiltinShadowMode::Other => {
let item = self.items.get(name);
if let Some(res) = item {
if let Some(ModuleDefId::ModuleId(_)) = res.def.take_types() {
return BUILTIN_SCOPE.get(name).or(item);
}
}
item.or_else(|| BUILTIN_SCOPE.get(name))
}
}
}
pub fn traits<'a>(&'a self) -> impl Iterator<Item = TraitId> + 'a {
self.items.values().filter_map(|r| match r.def.take_types() {
Some(ModuleDefId::TraitId(t)) => Some(t),
_ => None,
})
}
pub(crate) fn get_legacy_macro(&self, name: &Name) -> Option<MacroDefId> {
self.legacy_macros.get(name).copied()
}
}
#[derive(Debug, Clone, PartialEq, Eq, Default)]
pub struct Resolution {
/// None for unresolved
pub def: PerNs,
/// ident by which this is imported into local scope.
pub import: Option<LocalImportId>,
}