// randFloat64 generates a random float taking the full range of a float64.
func randFloat64(rand *rand.Rand) float64 {
f := rand.Float64()
if rand.Int()&1 == 1 {
f = -f
}
return f
}
// randFloat32 generates a random float taking the full range of a float32.
func randFloat32(rand *rand.Rand) float32 {
f := rand.Float64() * math.MaxFloat32
if rand.Int()&1 == 1 {
f = -f
}
return float32(f)
}
// Value returns an arbitrary value of the given type.
// If the type implements the Generator interface, that will be used.
// Note: in order to create arbitrary values for structs, all the members must be public.
func Value(t reflect.Type, rand *rand.Rand) (value reflect.Value, ok bool) {
if m, ok := reflect.Zero(t).Interface().(Generator); ok {
return m.Generate(rand, complexSize), true
}
switch concrete := t; concrete.Kind() {
case reflect.Bool:
return reflect.ValueOf(rand.Int()&1 == 0), true
case reflect.Float32:
return reflect.ValueOf(randFloat32(rand)), true
case reflect.Float64:
return reflect.ValueOf(randFloat64(rand)), true
case reflect.Complex64:
return reflect.ValueOf(complex(randFloat32(rand), randFloat32(rand))), true
case reflect.Complex128:
return reflect.ValueOf(complex(randFloat64(rand), randFloat64(rand))), true
case reflect.Int16:
return reflect.ValueOf(int16(randInt64(rand))), true
case reflect.Int32:
return reflect.ValueOf(int32(randInt64(rand))), true
case reflect.Int64:
return reflect.ValueOf(randInt64(rand)), true
case reflect.Int8:
return reflect.ValueOf(int8(randInt64(rand))), true
case reflect.Int:
return reflect.ValueOf(int(randInt64(rand))), true
case reflect.Uint16:
return reflect.ValueOf(uint16(randInt64(rand))), true
case reflect.Uint32:
return reflect.ValueOf(uint32(randInt64(rand))), true
case reflect.Uint64:
return reflect.ValueOf(uint64(randInt64(rand))), true
case reflect.Uint8:
return reflect.ValueOf(uint8(randInt64(rand))), true
case reflect.Uint:
return reflect.ValueOf(uint(randInt64(rand))), true
case reflect.Uintptr:
return reflect.ValueOf(uintptr(randInt64(rand))), true
case reflect.Map:
numElems := rand.Intn(complexSize)
m := reflect.MakeMap(concrete)
for i := 0; i < numElems; i++ {
key, ok1 := Value(concrete.Key(), rand)
value, ok2 := Value(concrete.Elem(), rand)
if !ok1 || !ok2 {
return reflect.Value{}, false
}
m.SetMapIndex(key, value)
}
return m, true
case reflect.Ptr:
v, ok := Value(concrete.Elem(), rand)
if !ok {
return reflect.Value{}, false
}
p := reflect.New(concrete.Elem())
p.Elem().Set(v)
return p, true
case reflect.Slice:
numElems := rand.Intn(complexSize)
s := reflect.MakeSlice(concrete, numElems, numElems)
for i := 0; i < numElems; i++ {
v, ok := Value(concrete.Elem(), rand)
if !ok {
return reflect.Value{}, false
}
s.Index(i).Set(v)
}
return s, true
case reflect.String:
numChars := rand.Intn(complexSize)
codePoints := make([]int, numChars)
for i := 0; i < numChars; i++ {
codePoints[i] = rand.Intn(0x10ffff)
}
return reflect.ValueOf(string(codePoints)), true
case reflect.Struct:
s := reflect.New(t).Elem()
for i := 0; i < s.NumField(); i++ {
v, ok := Value(concrete.Field(i).Type, rand)
if !ok {
return reflect.Value{}, false
}
s.Field(i).Set(v)
}
return s, true
default:
return reflect.Value{}, false
}
return
}
// Value returns an arbitrary value of the given type.
// If the type implements the Generator interface, that will be used.
// Note: in order to create arbitrary values for structs, all the members must be public.
func Value(t reflect.Type, rand *rand.Rand) (value reflect.Value, ok bool) {
if m, ok := reflect.MakeZero(t).Interface().(Generator); ok {
return m.Generate(rand, complexSize), true
}
switch concrete := t.(type) {
case *reflect.BoolType:
return reflect.NewValue(rand.Int()&1 == 0), true
case *reflect.Float32Type:
return reflect.NewValue(randFloat32(rand)), true
case *reflect.Float64Type:
return reflect.NewValue(randFloat64(rand)), true
case *reflect.FloatType:
if t.Size() == 4 {
return reflect.NewValue(float(randFloat32(rand))), true
} else {
return reflect.NewValue(float(randFloat64(rand))), true
}
case *reflect.Int16Type:
return reflect.NewValue(int16(randInt64(rand))), true
case *reflect.Int32Type:
return reflect.NewValue(int32(randInt64(rand))), true
case *reflect.Int64Type:
return reflect.NewValue(randInt64(rand)), true
case *reflect.Int8Type:
return reflect.NewValue(int8(randInt64(rand))), true
case *reflect.IntType:
return reflect.NewValue(int(randInt64(rand))), true
case *reflect.MapType:
numElems := rand.Intn(complexSize)
m := reflect.MakeMap(concrete)
for i := 0; i < numElems; i++ {
key, ok1 := Value(concrete.Key(), rand)
value, ok2 := Value(concrete.Elem(), rand)
if !ok1 || !ok2 {
return nil, false
}
m.SetElem(key, value)
}
return m, true
case *reflect.PtrType:
v, ok := Value(concrete.Elem(), rand)
if !ok {
return nil, false
}
p := reflect.MakeZero(concrete)
p.(*reflect.PtrValue).PointTo(v)
return p, true
case *reflect.SliceType:
numElems := rand.Intn(complexSize)
s := reflect.MakeSlice(concrete, numElems, numElems)
for i := 0; i < numElems; i++ {
v, ok := Value(concrete.Elem(), rand)
if !ok {
return nil, false
}
s.Elem(i).SetValue(v)
}
return s, true
case *reflect.StringType:
numChars := rand.Intn(complexSize)
codePoints := make([]int, numChars)
for i := 0; i < numChars; i++ {
codePoints[i] = rand.Intn(0x10ffff)
}
return reflect.NewValue(string(codePoints)), true
case *reflect.StructType:
s := reflect.MakeZero(t).(*reflect.StructValue)
for i := 0; i < s.NumField(); i++ {
v, ok := Value(concrete.Field(i).Type, rand)
if !ok {
return nil, false
}
s.Field(i).SetValue(v)
}
return s, true
case *reflect.Uint16Type:
return reflect.NewValue(uint16(randInt64(rand))), true
case *reflect.Uint32Type:
return reflect.NewValue(uint32(randInt64(rand))), true
case *reflect.Uint64Type:
return reflect.NewValue(uint64(randInt64(rand))), true
case *reflect.Uint8Type:
return reflect.NewValue(uint8(randInt64(rand))), true
case *reflect.UintType:
return reflect.NewValue(uint(randInt64(rand))), true
case *reflect.UintptrType:
return reflect.NewValue(uintptr(randInt64(rand))), true
default:
return nil, false
}
return
}
func uint8rand(r *rand.Rand) uint8 {
return uint8(r.Int() % 255)
}