Method lookup_inputs

src/expr/src/relation/join_input_mapper.rs:229–235

Find the sorted, dedupped set of inputs an expression references

(&self, expr: &C)

    /// Find the sorted, dedupped set of inputs an expression references
    pub fn lookup_inputs<C: Columns>(&self, expr: &C) -> impl Iterator<Item = usize> + use<C> {
        expr.support()
            .iter()
            .map(|c| self.input_relation[*c])
            .sorted()
            .dedup()
    }

    /// Returns the index of the only input referenced in the given expression.
    pub fn single_input(&self, expr: &impl Columns) -> Option<usize> {