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