Method normalize

pkg/sql/sem/tree/normalize.go:117–166

(v *NormalizeVisitor)

}

func (expr *BinaryExpr) normalize(v *NormalizeVisitor) TypedExpr {
	left := expr.TypedLeft()
	right := expr.TypedRight()
	expectedType := expr.ResolvedType()

	if !expr.fn.NullableArgs && (left == DNull || right == DNull) {
		return DNull
	}

	var final TypedExpr

	switch expr.Operator {
	case Plus:
		if v.isNumericZero(right) {
			final = ReType(left, expectedType)
			break
		}
		if v.isNumericZero(left) {
			final = ReType(right, expectedType)
			break
		}
	case Minus:
		if types.IsAdditiveType(left.ResolvedType()) && v.isNumericZero(right) {
			final = ReType(left, expectedType)
			break
		}
	case Mult:
		if v.isNumericOne(right) {
			final = ReType(left, expectedType)
			break
		}
		if v.isNumericOne(left) {
			final = ReType(right, expectedType)
			break
		}
		// We can't simplify multiplication by zero to zero,
		// because if the other operand is NULL during evaluation
		// the result must be NULL.
	case Div, FloorDiv:
		if v.isNumericOne(right) {
			final = ReType(left, expectedType)
			break
		}
	}

	if final == nil {
		return expr
	}
	return final
}

func (expr *AndExpr) normalize(v *NormalizeVisitor) TypedExpr {
	left := expr.TypedLeft()