Changed "BelongsTo" method by "IsA" and update Readme

README.md

@@ -5,12 +5,16 @@ It started as a fork of [Rob Pike’s Stringer tool](https://godoc.org/golang.or
 ## Generated functions and methods
 When Enumer is applied to a type, it will generate:
 
-* A method `String()` that returns the string representation of the enum value. This makes the enum conform
+* The following basic methods/function: 
+
+  * Method `String()`: returns the string representation of the enum value. This makes the enum conform
 the `Stringer` interface, so whenever you print an enum value, you'll get the string name instead of a number.
-* A function `<Type>String(s string)` to get the enum value from its string representation. This is useful
+  * Function `<Type>String(s string)`: returns the enum value from its string representation. This is useful
 when you need to read enum values from command line arguments, from a configuration file, or
 from a REST API request... In short, from those places where using the real enum value (an integer) would
 be almost meaningless or hard to trace or use by a human.
+  * Function `<Type>Values()`: returns a slice with all the value of the enum
+  * Method `IsA<Type>()`: returns true only if the current value is among the values of the enum. Useful for validations.
 * When the flag `json` is provided, two additional methods will be generated, `MarshalJSON()` and `UnmarshalJSON()`. These make
 the enum conform to the `json.Marshaler` and `json.Unmarshaler` interfaces. Very useful to use it in JSON APIs.
 * When the flag `text` is provided, two additional methods will be generated, `MarshalText()` and `UnmarshalText()`. These make
@@ -34,14 +38,22 @@ const (
 	Acetaminophen = Paracetamol
 )
 ```
-executing `enumer -type=Pill -json` will generate a new file with four methods:
+executing `enumer -type=Pill -json` will generate a new file with four basic method and two extra for JSON:
 ```go
-func (i Pill) String() string {
-    //...
+func (i Pill) String() string { 
+	//...
 }
 
-func PillString(s string) (Pill, error) {
-    //...
+func PillString(s string) (Pill, error) { 
+	//...
+}
+
+func PillValues() []Pill { 
+	//...
+}
+
+func (i Pill) IsAPill() bool { 
+	//...
 }
 
 func (i Pill) MarshalJSON() ([]byte, error) {
@@ -67,6 +79,16 @@ if err != nil {
 }
 // Now pill == Ibuprofen
 
+// Get all the values of the string
+allPills := PillValues()
+fmt.Println(allPills) // Will print [Placebo Aspirin Ibuprofen Paracetamol]
+
+// Check if a value belongs to the Pill enum values
+var notAPill Pill = 42
+if (notAPill.IsAPill()) {
+	fmt.Println(notAPill, "is not a value of the Pill enum")
+}
+
 // Marshal/unmarshal to/from json strings, either directly or automatically when
 // the enum is a field of a struct
 pillJSON := Aspirin.MarshalJSON()

enumer.go

@@ -24,8 +24,8 @@ func %[1]sValues() []%[1]s {
 
 // Arguments to format are:
 //	[1]: type name
-const stringBelongsMethodLoop = `// belongsTo%[1]s returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i %[1]s) belongsTo%[1]s() bool {
+const stringBelongsMethodLoop = `// IsA%[1]s returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i %[1]s) IsA%[1]s() bool {
 	for _, v := range _%[1]sValues {
 		if i == v {
 			return true
@@ -36,8 +36,8 @@ func (i %[1]s) belongsTo%[1]s() bool {
 `
 // Arguments to format are:
 //	[1]: type name
-const stringBelongsMethodSet = `// belongsTo%[1]s returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i %[1]s) belongsTo%[1]s() bool {
+const stringBelongsMethodSet = `// IsA%[1]s returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i %[1]s) IsA%[1]s() bool {
 	_, ok := _%[1]sMap[i] 
 	return ok
 }

golden_test.go

@@ -106,8 +106,8 @@ func DayValues() []Day {
 	return _DayValues
 }
 
-// belongsToDay returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i Day) belongsToDay() bool {
+// IsADay returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Day) IsADay() bool {
 	for _, v := range _DayValues {
 		if i == v {
 			return true
@@ -164,8 +164,8 @@ func NumberValues() []Number {
 	return _NumberValues
 }
 
-// belongsToNumber returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i Number) belongsToNumber() bool {
+// IsANumber returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Number) IsANumber() bool {
 	for _, v := range _NumberValues {
 		if i == v {
 			return true
@@ -244,8 +244,8 @@ func GapValues() []Gap {
 	return _GapValues
 }
 
-// belongsToGap returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i Gap) belongsToGap() bool {
+// IsAGap returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Gap) IsAGap() bool {
 	for _, v := range _GapValues {
 		if i == v {
 			return true
@@ -303,8 +303,8 @@ func NumValues() []Num {
 	return _NumValues
 }
 
-// belongsToNum returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i Num) belongsToNum() bool {
+// IsANum returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Num) IsANum() bool {
 	for _, v := range _NumValues {
 		if i == v {
 			return true
@@ -375,8 +375,8 @@ func UnumValues() []Unum {
 	return _UnumValues
 }
 
-// belongsToUnum returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i Unum) belongsToUnum() bool {
+// IsAUnum returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Unum) IsAUnum() bool {
 	for _, v := range _UnumValues {
 		if i == v {
 			return true
@@ -465,8 +465,8 @@ func PrimeValues() []Prime {
 	return _PrimeValues
 }
 
-// belongsToPrime returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i Prime) belongsToPrime() bool {
+// IsAPrime returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Prime) IsAPrime() bool {
 	_, ok := _PrimeMap[i]
 	return ok
 }
@@ -548,8 +548,8 @@ func PrimeValues() []Prime {
 	return _PrimeValues
 }
 
-// belongsToPrime returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i Prime) belongsToPrime() bool {
+// IsAPrime returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Prime) IsAPrime() bool {
 	_, ok := _PrimeMap[i]
 	return ok
 }
@@ -649,8 +649,8 @@ func PrimeValues() []Prime {
 	return _PrimeValues
 }
 
-// belongsToPrime returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i Prime) belongsToPrime() bool {
+// IsAPrime returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Prime) IsAPrime() bool {
 	_, ok := _PrimeMap[i]
 	return ok
 }
@@ -745,8 +745,8 @@ func PrimeValues() []Prime {
 	return _PrimeValues
 }
 
-// belongsToPrime returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i Prime) belongsToPrime() bool {
+// IsAPrime returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Prime) IsAPrime() bool {
 	_, ok := _PrimeMap[i]
 	return ok
 }
@@ -846,8 +846,8 @@ func PrimeValues() []Prime {
 	return _PrimeValues
 }
 
-// belongsToPrime returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i Prime) belongsToPrime() bool {
+// IsAPrime returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Prime) IsAPrime() bool {
 	_, ok := _PrimeMap[i]
 	return ok
 }
@@ -958,8 +958,8 @@ func PrimeValues() []Prime {
 	return _PrimeValues
 }
 
-// belongsToPrime returns "true" if the value is listed in the enum definition. "false" otherwise
-func (i Prime) belongsToPrime() bool {
+// IsAPrime returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Prime) IsAPrime() bool {
 	_, ok := _PrimeMap[i]
 	return ok
 }