Package structure refactor.

mysql/cast.go

@@ -0,0 +1,42 @@
+package mysql
+
+import (
+	"github.com/go-jet/jet/internal/jet"
+)
+
+type cast interface {
+	jet.Cast
+
+	AS_DATETIME() DateTimeExpression
+	AS_SIGNED() IntegerExpression
+	AS_UNSIGNED() IntegerExpression
+	AS_BINARY() StringExpression
+}
+
+type castImpl struct {
+	jet.CastImpl
+}
+
+func CAST(expr jet.Expression) cast {
+	castImpl := &castImpl{}
+
+	castImpl.CastImpl = jet.NewCastImpl(expr)
+
+	return castImpl
+}
+
+func (c *castImpl) AS_DATETIME() DateTimeExpression {
+	return jet.TimestampExp(c.AS("DATETIME"))
+}
+
+func (c *castImpl) AS_SIGNED() IntegerExpression {
+	return jet.IntExp(c.AS("SIGNED"))
+}
+
+func (c *castImpl) AS_UNSIGNED() IntegerExpression {
+	return jet.IntExp(c.AS("UNSIGNED"))
+}
+
+func (c *castImpl) AS_BINARY() StringExpression {
+	return jet.StringExp(c.AS("BINARY"))
+}