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//! FIXME: write short doc here
pub(crate) mod lower;
pub(crate) mod scope;
pub(crate) mod validation;
use std::{ops::Index, sync::Arc};
use ra_arena::{map::ArenaMap, Arena};
use ra_syntax::{ast, AstPtr};
use rustc_hash::FxHashMap;
use crate::{db::HirDatabase, DefWithBody, Either, HasSource, Resolver, Source};
pub use self::scope::ExprScopes;
pub use hir_def::expr::{
ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Literal, LogicOp, MatchArm,
Ordering, Pat, PatId, RecordFieldPat, RecordLitField, Statement, UnaryOp,
};
/// The body of an item (function, const etc.).
#[derive(Debug, Eq, PartialEq)]
pub struct Body {
/// The def of the item this body belongs to
owner: DefWithBody,
exprs: Arena<ExprId, Expr>,
pats: Arena<PatId, Pat>,
/// The patterns for the function's parameters. While the parameter types are
/// part of the function signature, the patterns are not (they don't change
/// the external type of the function).
///
/// If this `Body` is for the body of a constant, this will just be
/// empty.
params: Vec<PatId>,
/// The `ExprId` of the actual body expression.
body_expr: ExprId,
}
type ExprPtr = Either<AstPtr<ast::Expr>, AstPtr<ast::RecordField>>;
type ExprSource = Source<ExprPtr>;
type PatPtr = Either<AstPtr<ast::Pat>, AstPtr<ast::SelfParam>>;
type PatSource = Source<PatPtr>;
/// An item body together with the mapping from syntax nodes to HIR expression
/// IDs. This is needed to go from e.g. a position in a file to the HIR
/// expression containing it; but for type inference etc., we want to operate on
/// a structure that is agnostic to the actual positions of expressions in the
/// file, so that we don't recompute types whenever some whitespace is typed.
///
/// One complication here is that, due to macro expansion, a single `Body` might
/// be spread across several files. So, for each ExprId and PatId, we record
/// both the HirFileId and the position inside the file. However, we only store
/// AST -> ExprId mapping for non-macro files, as it is not clear how to handle
/// this properly for macros.
#[derive(Default, Debug, Eq, PartialEq)]
pub struct BodySourceMap {
expr_map: FxHashMap<ExprPtr, ExprId>,
expr_map_back: ArenaMap<ExprId, ExprSource>,
pat_map: FxHashMap<PatPtr, PatId>,
pat_map_back: ArenaMap<PatId, PatSource>,
field_map: FxHashMap<(ExprId, usize), AstPtr<ast::RecordField>>,
}
impl Body {
pub(crate) fn body_with_source_map_query(
db: &impl HirDatabase,
def: DefWithBody,
) -> (Arc<Body>, Arc<BodySourceMap>) {
let mut params = None;
let (file_id, body) = match def {
DefWithBody::Function(f) => {
let src = f.source(db);
params = src.ast.param_list();
(src.file_id, src.ast.body().map(ast::Expr::from))
}
DefWithBody::Const(c) => {
let src = c.source(db);
(src.file_id, src.ast.body())
}
DefWithBody::Static(s) => {
let src = s.source(db);
(src.file_id, src.ast.body())
}
};
let (body, source_map) = lower::lower(db, def.resolver(db), file_id, def, params, body);
(Arc::new(body), Arc::new(source_map))
}
pub(crate) fn body_query(db: &impl HirDatabase, def: DefWithBody) -> Arc<Body> {
db.body_with_source_map(def).0
}
pub fn params(&self) -> &[PatId] {
&self.params
}
pub fn body_expr(&self) -> ExprId {
self.body_expr
}
pub fn owner(&self) -> DefWithBody {
self.owner
}
pub fn exprs(&self) -> impl Iterator<Item = (ExprId, &Expr)> {
self.exprs.iter()
}
pub fn pats(&self) -> impl Iterator<Item = (PatId, &Pat)> {
self.pats.iter()
}
}
// needs arbitrary_self_types to be a method... or maybe move to the def?
pub(crate) fn resolver_for_expr(
body: Arc<Body>,
db: &impl HirDatabase,
expr_id: ExprId,
) -> Resolver {
let scopes = db.expr_scopes(body.owner);
resolver_for_scope(body, db, scopes.scope_for(expr_id))
}
pub(crate) fn resolver_for_scope(
body: Arc<Body>,
db: &impl HirDatabase,
scope_id: Option<scope::ScopeId>,
) -> Resolver {
let mut r = body.owner.resolver(db);
let scopes = db.expr_scopes(body.owner);
let scope_chain = scopes.scope_chain(scope_id).collect::<Vec<_>>();
for scope in scope_chain.into_iter().rev() {
r = r.push_expr_scope(Arc::clone(&scopes), scope);
}
r
}
impl Index<ExprId> for Body {
type Output = Expr;
fn index(&self, expr: ExprId) -> &Expr {
&self.exprs[expr]
}
}
impl Index<PatId> for Body {
type Output = Pat;
fn index(&self, pat: PatId) -> &Pat {
&self.pats[pat]
}
}
impl BodySourceMap {
pub(crate) fn expr_syntax(&self, expr: ExprId) -> Option<ExprSource> {
self.expr_map_back.get(expr).copied()
}
pub(crate) fn node_expr(&self, node: &ast::Expr) -> Option<ExprId> {
self.expr_map.get(&Either::A(AstPtr::new(node))).cloned()
}
pub(crate) fn pat_syntax(&self, pat: PatId) -> Option<PatSource> {
self.pat_map_back.get(pat).copied()
}
pub(crate) fn node_pat(&self, node: &ast::Pat) -> Option<PatId> {
self.pat_map.get(&Either::A(AstPtr::new(node))).cloned()
}
pub(crate) fn field_syntax(&self, expr: ExprId, field: usize) -> AstPtr<ast::RecordField> {
self.field_map[&(expr, field)]
}
}
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