Introduce AssocOp::Binary.

It mirrors `ExprKind::Binary`, and contains a `BinOpKind`. This makes
`AssocOp` more like `ExprKind`. Note that the variants removed from
`AssocOp` are all named differently to `BinOpToken`, e.g. `Multiply`
instead of `Mul`, so that's an inconsistency removed.

The commit adds `precedence` and `fixity` methods to `BinOpKind`, and
calls them from the corresponding methods in `AssocOp`. This avoids the
need to create an `AssocOp` from a `BinOpKind` in a bunch of places, and
`AssocOp::from_ast_binop` is removed.

`AssocOp::to_ast_binop` is also no longer needed.

Overall things are shorter and nicer.
This commit is contained in:
Nicholas Nethercote
2024-12-19 18:24:07 +11:00
parent a8364f3b2a
commit ceafbad81f
10 changed files with 152 additions and 256 deletions

View File

@@ -39,7 +39,7 @@ pub use crate::format::*;
use crate::ptr::P;
use crate::token::{self, CommentKind, Delimiter};
use crate::tokenstream::{DelimSpan, LazyAttrTokenStream, TokenStream};
use crate::util::parser::{AssocOp, ExprPrecedence};
use crate::util::parser::{ExprPrecedence, Fixity};
/// A "Label" is an identifier of some point in sources,
/// e.g. in the following code:
@@ -937,8 +937,37 @@ impl BinOpKind {
matches!(self, BinOpKind::And | BinOpKind::Or)
}
pub fn precedence(&self) -> ExprPrecedence {
use BinOpKind::*;
match *self {
Mul | Div | Rem => ExprPrecedence::Product,
Add | Sub => ExprPrecedence::Sum,
Shl | Shr => ExprPrecedence::Shift,
BitAnd => ExprPrecedence::BitAnd,
BitXor => ExprPrecedence::BitXor,
BitOr => ExprPrecedence::BitOr,
Lt | Gt | Le | Ge | Eq | Ne => ExprPrecedence::Compare,
And => ExprPrecedence::LAnd,
Or => ExprPrecedence::LOr,
}
}
pub fn fixity(&self) -> Fixity {
use BinOpKind::*;
match self {
Eq | Ne | Lt | Le | Gt | Ge => Fixity::None,
Add | Sub | Mul | Div | Rem | And | Or | BitXor | BitAnd | BitOr | Shl | Shr => {
Fixity::Left
}
}
}
pub fn is_comparison(self) -> bool {
crate::util::parser::AssocOp::from_ast_binop(self).is_comparison()
use BinOpKind::*;
match self {
Eq | Ne | Lt | Le | Gt | Ge => true,
Add | Sub | Mul | Div | Rem | And | Or | BitXor | BitAnd | BitOr | Shl | Shr => false,
}
}
/// Returns `true` if the binary operator takes its arguments by value.
@@ -1332,7 +1361,7 @@ impl Expr {
ExprKind::Range(..) => ExprPrecedence::Range,
// Binop-like expr kinds, handled by `AssocOp`.
ExprKind::Binary(op, ..) => AssocOp::from_ast_binop(op.node).precedence(),
ExprKind::Binary(op, ..) => op.node.precedence(),
ExprKind::Cast(..) => ExprPrecedence::Cast,
ExprKind::Assign(..) |