mysqldef: add Enum type support

mysqldef/decimal.go

@@ -163,6 +163,8 @@ func ConvertToDecimal(value interface{}) (Decimal, error) {
 		return NewDecimalFromInt(int64(v.Value), 0), nil
 	case Bit:
 		return NewDecimalFromUint(uint64(v.Value), 0), nil
+	case Enum:
+		return NewDecimalFromUint(uint64(v.Value), 0), nil
 	default:
 		return Decimal{}, fmt.Errorf("can't convert %v to decimal", value)
 	}

mysqldef/enum.go

@@ -0,0 +1,55 @@
+// Copyright 2015 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mysqldef
+
+import (
+	"strings"
+
+	"github.com/juju/errors"
+)
+
+// Enum is for MySQL enum type.
+type Enum struct {
+	Name  string
+	Value uint64
+}
+
+// String implements fmt.Stringer interface.
+func (e Enum) String() string {
+	return e.Name
+}
+
+// ToNumber changes enum index to float64 for numeric operation.
+func (e Enum) ToNumber() float64 {
+	return float64(e.Value)
+}
+
+// ParseEnumName creates a Enum with item name.
+func ParseEnumName(elems []string, name string) (Enum, error) {
+	for i, n := range elems {
+		if strings.EqualFold(n, name) {
+			return Enum{Name: n, Value: uint64(i) + 1}, nil
+		}
+	}
+	return Enum{}, errors.Errorf("item %s is not in enum %v", name, elems)
+}
+
+// ParseEnumValue creates a Enum with special number.
+func ParseEnumValue(elems []string, number uint64) (Enum, error) {
+	if number <= 0 || number > uint64(len(elems)) {
+		return Enum{}, errors.Errorf("number %d overflow enum boundary [1, %d]", number, len(elems))
+	}
+
+	return Enum{Name: elems[number-1], Value: number}, nil
+}

mysqldef/enum_test.go

@@ -0,0 +1,68 @@
+// Copyright 2015 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mysqldef
+
+import (
+	. "github.com/pingcap/check"
+)
+
+var _ = Suite(&testEnumSuite{})
+
+type testEnumSuite struct {
+}
+
+func (s *testEnumSuite) TestEnum(c *C) {
+	tbl := []struct {
+		Elems    []string
+		Name     string
+		Expected int
+	}{
+		{[]string{"a", "b"}, "a", 1},
+		{[]string{"a"}, "b", 0},
+	}
+
+	for _, t := range tbl {
+		e, err := ParseEnumName(t.Elems, t.Name)
+		if t.Expected == 0 {
+			c.Assert(err, NotNil)
+			c.Assert(e.ToNumber(), Equals, float64(0))
+			c.Assert(e.String(), Equals, "")
+			continue
+		}
+
+		c.Assert(err, IsNil)
+		c.Assert(e.String(), Equals, t.Name)
+		c.Assert(e.ToNumber(), Equals, float64(t.Expected))
+	}
+
+	tblNumber := []struct {
+		Elems    []string
+		Number   uint64
+		Expected int
+	}{
+		{[]string{"a"}, 1, 1},
+		{[]string{"a"}, 0, 0},
+	}
+
+	for _, t := range tblNumber {
+		e, err := ParseEnumValue(t.Elems, t.Number)
+		if t.Expected == 0 {
+			c.Assert(err, NotNil)
+			continue
+		}
+
+		c.Assert(err, IsNil)
+		c.Assert(e.ToNumber(), Equals, float64(t.Expected))
+	}
+}