20 lines
574 B
Rust
20 lines
574 B
Rust
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use rustc_front::hir::{BinOp_, Expr};
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#[derive(PartialEq, Eq, Debug, Copy, Clone)]
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pub enum Rel {
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Lt,
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Le,
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}
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/// Put the expression in the form `lhs < rhs` or `lhs <= rhs`.
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pub fn normalize_comparison<'a>(op: BinOp_, lhs: &'a Expr, rhs: &'a Expr)
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-> Option<(Rel, &'a Expr, &'a Expr)> {
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match op {
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BinOp_::BiLt => Some((Rel::Lt, lhs, rhs)),
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BinOp_::BiLe => Some((Rel::Le, lhs, rhs)),
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BinOp_::BiGt => Some((Rel::Lt, rhs, lhs)),
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BinOp_::BiGe => Some((Rel::Le, rhs, lhs)),
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_ => None,
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}
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}
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