Method populate_expression

src/transform/src/cse/anf.rs:320–333

Populates `expression` with necessary `Let` bindings. This population may result in substantially more `Let` bindings that one might expect. It is very appropriate to run the `NormalizeLets` transformation afterwards to remove `Let` bindings that it deems unhelpful.

(self, expression: &mut MirRelationExpr)

    /// might expect. It is very appropriate to run the `NormalizeLets` transformation
    /// afterwards to remove `Let` bindings that it deems unhelpful.
    fn populate_expression(self, expression: &mut MirRelationExpr) {
        // Convert the bindings in to a sequence, by the local identifier.
        let mut bindings = self.bindings.into_iter().collect::<Vec<_>>();
        bindings.sort_by_key(|(_, i)| *i);

        for (value, index) in bindings.into_iter().rev() {
            let new_expression = MirRelationExpr::Let {
                id: LocalId::new(index),
                value: Box::new(value),
                body: Box::new(expression.take_dangerous()),
            };
            *expression = new_expression;
        }
    }
}