Function compare

compiler/optimizer/pruner.go:116–120

compare returns a DAG expression for a standard comparison operator but uses a call to the SuperSQL function "compare()" as standard comparisons do not handle nullsmax or cross-type comparisons (which can arise when the pool key value type changes).

(op string, lhs, rhs dag.Expr)

// do not handle nullsmax or cross-type comparisons (which can arise when the
// pool key value type changes).
func compare(op string, lhs, rhs dag.Expr) *dag.BinaryExpr {
	nullsMax := &dag.PrimitiveExpr{Kind: "PrimitiveExpr", Value: "true"}
	call := dag.NewCall("compare", []dag.Expr{lhs, rhs, nullsMax})
	return dag.NewBinaryExpr(op, call, &dag.PrimitiveExpr{Kind: "PrimitiveExpr", Value: "0"})
}

func literalComparison(e *dag.BinaryExpr) (*dag.ThisExpr, *dag.PrimitiveExpr, string) {
	switch lhs := e.LHS.(type) {