rust/crates/hir_ty/src/op.rs
Florian Diebold 6c32bbf3ca Separate Ty and TyKind like in Chalk
Currently `Ty` just wraps `TyKind`, but this allows us to change most
places to already use `intern` / `interned`.
2021-03-13 16:17:15 +01:00

57 lines
2.5 KiB
Rust

//! Helper functions for binary operator type inference.
use chalk_ir::TyVariableKind;
use hir_def::expr::{ArithOp, BinaryOp, CmpOp};
use crate::{Interner, Scalar, Ty, TyKind};
pub(super) fn binary_op_return_ty(op: BinaryOp, lhs_ty: Ty, rhs_ty: Ty) -> Ty {
match op {
BinaryOp::LogicOp(_) | BinaryOp::CmpOp(_) => TyKind::Scalar(Scalar::Bool).intern(&Interner),
BinaryOp::Assignment { .. } => Ty::unit(),
BinaryOp::ArithOp(ArithOp::Shl) | BinaryOp::ArithOp(ArithOp::Shr) => {
match lhs_ty.interned(&Interner) {
TyKind::Scalar(Scalar::Int(_))
| TyKind::Scalar(Scalar::Uint(_))
| TyKind::Scalar(Scalar::Float(_)) => lhs_ty,
TyKind::InferenceVar(_, TyVariableKind::Integer)
| TyKind::InferenceVar(_, TyVariableKind::Float) => lhs_ty,
_ => TyKind::Unknown.intern(&Interner),
}
}
BinaryOp::ArithOp(_) => match rhs_ty.interned(&Interner) {
TyKind::Scalar(Scalar::Int(_))
| TyKind::Scalar(Scalar::Uint(_))
| TyKind::Scalar(Scalar::Float(_)) => rhs_ty,
TyKind::InferenceVar(_, TyVariableKind::Integer)
| TyKind::InferenceVar(_, TyVariableKind::Float) => rhs_ty,
_ => TyKind::Unknown.intern(&Interner),
},
}
}
pub(super) fn binary_op_rhs_expectation(op: BinaryOp, lhs_ty: Ty) -> Ty {
match op {
BinaryOp::LogicOp(..) => TyKind::Scalar(Scalar::Bool).intern(&Interner),
BinaryOp::Assignment { op: None } => lhs_ty,
BinaryOp::CmpOp(CmpOp::Eq { .. }) => match lhs_ty.interned(&Interner) {
TyKind::Scalar(_) | TyKind::Str => lhs_ty,
TyKind::InferenceVar(_, TyVariableKind::Integer)
| TyKind::InferenceVar(_, TyVariableKind::Float) => lhs_ty,
_ => TyKind::Unknown.intern(&Interner),
},
BinaryOp::ArithOp(ArithOp::Shl) | BinaryOp::ArithOp(ArithOp::Shr) => {
TyKind::Unknown.intern(&Interner)
}
BinaryOp::CmpOp(CmpOp::Ord { .. })
| BinaryOp::Assignment { op: Some(_) }
| BinaryOp::ArithOp(_) => match lhs_ty.interned(&Interner) {
TyKind::Scalar(Scalar::Int(_))
| TyKind::Scalar(Scalar::Uint(_))
| TyKind::Scalar(Scalar::Float(_)) => lhs_ty,
TyKind::InferenceVar(_, TyVariableKind::Integer)
| TyKind::InferenceVar(_, TyVariableKind::Float) => lhs_ty,
_ => TyKind::Unknown.intern(&Interner),
},
}
}