//! Context for lowering paths. use std::cell::OnceCell; use hir_expand::{ ast_id_map::{AstIdMap, AstIdNode}, span::{SpanMap, SpanMapRef}, AstId, HirFileId, InFile, }; use syntax::ast; use triomphe::Arc; use crate::{db::DefDatabase, path::Path}; pub struct LowerCtx<'a> { pub db: &'a dyn DefDatabase, hygiene: SpanMap, // FIXME: This optimization is probably pointless, ast id map should pretty much always exist anyways. ast_id_map: Option<(HirFileId, OnceCell>)>, } impl<'a> LowerCtx<'a> { pub fn new(db: &'a dyn DefDatabase, hygiene: SpanMap, file_id: HirFileId) -> Self { LowerCtx { db, hygiene, ast_id_map: Some((file_id, OnceCell::new())) } } pub fn with_file_id(db: &'a dyn DefDatabase, file_id: HirFileId) -> Self { LowerCtx { db, hygiene: db.span_map(file_id), ast_id_map: Some((file_id, OnceCell::new())) } } pub fn with_hygiene(db: &'a dyn DefDatabase, hygiene: SpanMap) -> Self { LowerCtx { db, hygiene, ast_id_map: None } } pub(crate) fn span_map(&self) -> SpanMapRef<'_> { self.hygiene.as_ref() } pub(crate) fn lower_path(&self, ast: ast::Path) -> Option { Path::from_src(ast, self) } pub(crate) fn ast_id(&self, item: &N) -> Option> { let &(file_id, ref ast_id_map) = self.ast_id_map.as_ref()?; let ast_id_map = ast_id_map.get_or_init(|| self.db.ast_id_map(file_id)); Some(InFile::new(file_id, ast_id_map.ast_id(item))) } }