rust-lang/rust
1
0
Fork 0
Code Issues Pull Requests Actions 1 Packages Projects Releases Wiki Activity

Eliminate precedence arithmetic from rustc_hir_pretty

Browse Source
This commit is contained in:
David Tolnay
2024-11-28 13:50:04 -08:00
parent c02032cd6a
commit 34a65f203f
1 changed files with 15 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
compiler/rustc_hir_pretty/src/lib.rs
View File

@@ -1162,32 +1162,33 @@ impl<'a> State<'a> {
fn print_expr_binary(&mut self, op: hir::BinOp, lhs: &hir::Expr<'_>, rhs: &hir::Expr<'_>) {
let assoc_op = AssocOp::from_ast_binop(op.node);
let prec = assoc_op.precedence() as i8;
let fixity = assoc_op.fixity();
let binop_prec = assoc_op.precedence() as i8;
let left_prec = lhs.precedence();
let right_prec = rhs.precedence();
let (left_prec, right_prec) = match fixity {
Fixity::Left => (prec, prec + 1),
Fixity::Right => (prec + 1, prec),
Fixity::None => (prec + 1, prec + 1),
let (mut left_needs_paren, right_needs_paren) = match assoc_op.fixity() {
Fixity::Left => (left_prec < binop_prec, right_prec <= binop_prec),
Fixity::Right => (left_prec <= binop_prec, right_prec < binop_prec),
Fixity::None => (left_prec <= binop_prec, right_prec <= binop_prec),
};
let left_prec = match (&lhs.kind, op.node) {
match (&lhs.kind, op.node) {
// These cases need parens: `x as i32 < y` has the parser thinking that `i32 < y` is
// the beginning of a path type. It starts trying to parse `x as (i32 < y ...` instead
// of `(x as i32) < ...`. We need to convince it _not_ to do that.
(&hir::ExprKind::Cast { .. }, hir::BinOpKind::Lt | hir::BinOpKind::Shl) => {
parser::PREC_FORCE_PAREN
left_needs_paren = true;
}
(&hir::ExprKind::Let { .. }, _) if !parser::needs_par_as_let_scrutinee(prec) => {
parser::PREC_FORCE_PAREN
(&hir::ExprKind::Let { .. }, _) if !parser::needs_par_as_let_scrutinee(binop_prec) => {
left_needs_paren = true;
}
_ => left_prec,
};
_ => {}
}
self.print_expr_cond_paren(lhs, lhs.precedence() < left_prec);
self.print_expr_cond_paren(lhs, left_needs_paren);
self.space();
self.word_space(op.node.as_str());
self.print_expr_cond_paren(rhs, rhs.precedence() < right_prec)
self.print_expr_cond_paren(rhs, right_needs_paren);
}
fn print_expr_unary(&mut self, op: hir::UnOp, expr: &hir::Expr<'_>) {