Method map_expr_to_local

src/expr/src/relation/join_input_mapper.rs:184–189

Takes an expression from the global context and creates a new version where column references have been remapped to the local context. Assumes that all columns in `expr` are from the same input.

(&self, mut expr: C)

    /// where column references have been remapped to the local context.
    /// Assumes that all columns in `expr` are from the same input.
    pub fn map_expr_to_local<C: Columns + Sized>(&self, mut expr: C) -> C {
        expr.visit_columns(|c| {
            *c -= self.prior_arities[self.input_relation[*c]];
        });
        expr
    }

    /// Takes an expression from the local context of the `index`th input and
    /// creates a new version where column references have been remapped to the