v0.12.0

Since this version, it begins supporting to handle the values of any type which supported by database/sql on Scan and Value functions in that sql package. Thank you for the contributions, @RangelReale and @nikhrom.

New Features

• Use default sql package functions for Scanner and Valuer #32 @RangelReale
• Use go:linkname for database/sql.convertAssign #33 @moznion

Bug Fixes

• fix compilation error #40 @nikhrom

Maintenance

• Support go 1.21.x on CI #34 @moznion
• Update module github.com/mattn/go-sqlite3 to v1.14.18 #35 @renovate-bot
• Update module github.com/mattn/go-sqlite3 to v1.14.19 #36 @renovate-bot
• Update module github.com/mattn/go-sqlite3 to v1.14.22 #38 @renovate-bot
• Update module github.com/stretchr/testify to v1.9.0 #39 @renovate-bot

v0.11.0

New Features

• Implements database/sql/driver.Valuer and database/sql.Scanner on Option type #30
• Support UnwrapAsPtr() method to unwrap the Option value as a pointer #28

Maintenance

• Add the target golang runtime version 1.20.x for CI #29
• Update module github.com/stretchr/testify to v1.8.4 #26
• Update module github.com/stretchr/testify to v1.8.3 #24
• Update module github.com/stretchr/testify to v1.8.2 #23

Documents

• Document for UnwrapAsPtr #31

v0.10.0

New Feature with Breaking Change

Support "correct" #OrElse() function #22

This feature changes the method signature of the #OrElse() that was introduced by v0.9.0, becoming to take a function that provides the fallback optional value. And the old implementation has been renamed #Or().

v0.9.0

New Features

• Support #OrElse() that supports to return the Option value according to the actual value existence #21
  • godoc: https://pkg.go.dev/github.com/moznion/go-optional#Option.OrElse

v0.8.0

New Features

• Support Stringer interface on Optional[T] #19

v0.7.0

New Features

Support two value factory methods: FromNillable() and PtrFromNillable() #18

These methods accept the nillable pointer value as an argument and make the Optional[T] type value.

FromNillable()

If the given value is not nil, this returns Some[T] value with doing value-dereference.
On the other hand, if the value is nil, this returns None[T].

example:

num := 123

some := FromNillable[int](&num)
fmt.Printf("%v\n", some.IsSome()) // => true
fmt.Printf("%v\n", some.Unwrap()) // => 123

none := FromNillable[int](nil)
fmt.Printf("%v\n", none.IsSome()) // => false
fmt.Printf("%v\n", none.Unwrap()) // => 0 (the default value of int)

PtrFromNillable()

If the given value is not nil, this returns Some[*T] value without doing value-dereference.
On the other hand, if the value is nil, this returns None[*T].

example:

num := 123

some := PtrFromNillable[int](&num)
fmt.Printf("%v\n", some.IsSome())  // => true
fmt.Printf("%v\n", *some.Unwrap()) // => 123 (NOTE: it needs doing dereference)

none := PtrFromNillable[int](nil)
fmt.Printf("%v\n", none.IsSome()) // => false
fmt.Printf("%v\n", none.Unwrap()) // => nil

v0.6.0

New Features

Support omitempty option on JSON marshaling #17

This version brings up the support for the omitempty option on JSON marshaling. If the property has that option and the value is None[T], it omits that property from the serialized JSON string.

example:

type JSONStruct struct {
	OmitemptyVal Option[string] `json:"omitemptyVal,omitempty"` // this should be omitted
}
jsonStruct := &JSONStruct{OmitemptyVal: None[string]()}
marshal, err := json.Marshal(jsonStruct)
if err != nil {
	return err
}
fmt.Printf("%s\n", marshal) // => {}

Maintenance

• Add go1.19 checking in GitHub Actions #15
• Update module github.com/stretchr/testify to v1.8.1 #16

v0.5.0

What's Changed

New Features

• Support JSON marshal and unmarshal for Option[T] value #13

Documents

• Tweak the grammatical items in godoc #14

Dependencies

• Update module go to 1.19 #12
• Update module github.com/stretchr/testify to v1.8.0 #11

v0.4.0

What's Changed

New Features

Support FlatMap functions: #10 (@moznion)

This version begins to support the following new methods:

• FlatMap[T, U any](option Option[T], mapper func(v T) Option[U]) Option[U]
• FlatMapOr[T, U any](option Option[T], fallbackValue U, mapper func(v T) Option[U]) U
• FlatMapWithError[T, U any](option Option[T], mapper func(v T) (Option[U], error)) (Option[U], error)
• FlatMapOrWithError[T, U any](option Option[T], fallbackValue U, mapper func(v T) (Option[U], error)) (U, error)

Please refer to the godoc for more details: https://pkg.go.dev/github.com/moznion/go-optional

v0.3.0

What's Changed

New Features

• Support Option[T]#Unwrap() method #9 (@moznion)