Package structure refactor.

alias.go

@@ -1,34 +0,0 @@
-package jet
-
-type alias struct {
-	expression Expression
-	alias      string
-}
-
-func newAlias(expression Expression, aliasName string) projection {
-	return &alias{
-		expression: expression,
-		alias:      aliasName,
-	}
-}
-
-func (a *alias) from(subQuery SelectTable) projection {
-	column := newColumn(a.alias, "", nil)
-	column.parent = &column
-	column.subQuery = subQuery
-
-	return &column
-}
-
-func (a *alias) serializeForProjection(statement statementType, out *sqlBuilder) error {
-	err := a.expression.serialize(statement, out)
-
-	if err != nil {
-		return err
-	}
-
-	out.writeString("AS")
-	out.writeAlias(a.alias)
-
-	return nil
-}