fork github.com/doug-martin

exp/case.go

@@ -0,0 +1,78 @@
+package exp
+
+type (
+	caseElse struct {
+		result interface{}
+	}
+	caseWhen struct {
+		caseElse
+		condition interface{}
+	}
+	caseExpression struct {
+		value         interface{}
+		whens         []CaseWhen
+		elseCondition CaseElse
+	}
+)
+
+func NewCaseElse(result interface{}) CaseElse {
+	return caseElse{result: result}
+}
+
+func (ce caseElse) Result() interface{} {
+	return ce.result
+}
+
+func NewCaseWhen(condition, result interface{}) CaseWhen {
+	return caseWhen{caseElse: caseElse{result: result}, condition: condition}
+}
+
+func (cw caseWhen) Condition() interface{} {
+	return cw.condition
+}
+
+func NewCaseExpression() CaseExpression {
+	return caseExpression{value: nil, whens: []CaseWhen{}, elseCondition: nil}
+}
+
+func (c caseExpression) Expression() Expression {
+	return c
+}
+
+func (c caseExpression) Clone() Expression {
+	return caseExpression{value: c.value, whens: c.whens, elseCondition: c.elseCondition}
+}
+
+func (c caseExpression) As(alias interface{}) AliasedExpression {
+	return NewAliasExpression(c, alias)
+}
+
+func (c caseExpression) GetValue() interface{} {
+	return c.value
+}
+
+func (c caseExpression) GetWhens() []CaseWhen {
+	return c.whens
+}
+
+func (c caseExpression) GetElse() CaseElse {
+	return c.elseCondition
+}
+
+func (c caseExpression) Value(value interface{}) CaseExpression {
+	c.value = value
+	return c
+}
+
+func (c caseExpression) When(condition, result interface{}) CaseExpression {
+	c.whens = append(c.whens, NewCaseWhen(condition, result))
+	return c
+}
+
+func (c caseExpression) Else(result interface{}) CaseExpression {
+	c.elseCondition = NewCaseElse(result)
+	return c
+}
+
+func (c caseExpression) Asc() OrderedExpression  { return asc(c) }
+func (c caseExpression) Desc() OrderedExpression { return desc(c) }