Bool expression refactoring.

sqlbuilder/types.go

@@ -4,36 +4,17 @@ import (
 	"bytes"
 )
 
-type Clause interface {
-	SerializeSql(out *bytes.Buffer) error
-}
-
 // A clause that can be used in order by
 type OrderByClause interface {
 	Clause
 	isOrderByClauseInterface
 }
 
-// An expression
-type Expression interface {
-	Clause
-	isExpressionInterface
-}
-
-type BoolExpression interface {
-	Clause
-	isBoolExpressionInterface
-
-	And(expression BoolExpression) BoolExpression
-	Or(expression BoolExpression) BoolExpression
-}
-
 // A clause that is selectable.
 type Projection interface {
 	Clause
 	isProjectionInterface
 
-	As(alias string) Projection
 	SerializeSqlForColumnList(out *bytes.Buffer) error
 }
 
@@ -82,28 +63,6 @@ type isOrderByClause struct {
 func (o *isOrderByClause) isOrderByClauseType() {
 }
 
-type isExpressionInterface interface {
-	isExpressionType()
-}
-
-type isExpression struct {
-	isOrderByClause // can always use expression in order by.
-}
-
-func (e *isExpression) isExpressionType() {
-}
-
-type isBoolExpressionInterface interface {
-	isExpressionInterface
-	isBoolExpressionType()
-}
-
-type isBoolExpression struct {
-}
-
-func (e *isBoolExpression) isBoolExpressionType() {
-}
-
 type isProjectionInterface interface {
 	isProjectionType()
 }