Package structure refactor.

internal/jet/order_by_clause.go

@@ -0,0 +1,35 @@
+package jet
+
+import "errors"
+
+// OrderByClause
+type orderByClause interface {
+	serializeForOrderBy(statement StatementType, out *SqlBuilder) error
+}
+
+type orderByClauseImpl struct {
+	expression Expression
+	ascent     bool
+}
+
+func (o *orderByClauseImpl) serializeForOrderBy(statement StatementType, out *SqlBuilder) error {
+	if o.expression == nil {
+		return errors.New("jet: nil orderBy by clause")
+	}
+
+	if err := o.expression.serializeForOrderBy(statement, out); err != nil {
+		return err
+	}
+
+	if o.ascent {
+		out.WriteString("ASC")
+	} else {
+		out.WriteString("DESC")
+	}
+
+	return nil
+}
+
+func newOrderByClause(expression Expression, ascent bool) orderByClause {
+	return &orderByClauseImpl{expression: expression, ascent: ascent}
+}