fork github.com/doug-martin

exp/order.go

@@ -0,0 +1,52 @@
+package exp
+
+type (
+	orderedExpression struct {
+		sortExpression Expression
+		direction      SortDirection
+		nullSortType   NullSortType
+	}
+)
+
+// used internally to create a new SORT_ASC OrderedExpression
+func asc(exp Expression) OrderedExpression {
+	return NewOrderedExpression(exp, AscDir, NoNullsSortType)
+}
+
+// used internally to create a new SORT_DESC OrderedExpression
+func desc(exp Expression) OrderedExpression {
+	return NewOrderedExpression(exp, DescSortDir, NoNullsSortType)
+}
+
+// used internally to create a new SORT_ASC OrderedExpression
+func NewOrderedExpression(exp Expression, direction SortDirection, sortType NullSortType) OrderedExpression {
+	return orderedExpression{sortExpression: exp, direction: direction, nullSortType: sortType}
+}
+
+func (oe orderedExpression) Clone() Expression {
+	return NewOrderedExpression(oe.sortExpression, oe.direction, oe.nullSortType)
+}
+
+func (oe orderedExpression) Expression() Expression {
+	return oe
+}
+
+func (oe orderedExpression) SortExpression() Expression {
+	return oe.sortExpression
+}
+
+func (oe orderedExpression) IsAsc() bool {
+	return oe.direction == AscDir
+}
+
+func (oe orderedExpression) NullSortType() NullSortType {
+	return oe.nullSortType
+}
+
+func (oe orderedExpression) NullsFirst() OrderedExpression {
+	return NewOrderedExpression(oe.sortExpression, oe.direction, NullsFirstSortType)
+}
+
+func (oe orderedExpression) NullsLast() OrderedExpression {
+	return NewOrderedExpression(oe.sortExpression, oe.direction, NullsLastSortType)
+}