Last active
February 15, 2023 13:35
-
-
Save williammartin/d9bf151f2a24fae900a2393611852b2c to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
# typed: strict | |
require 'sorbet-runtime' | |
module Result | |
extend T::Sig | |
extend T::Helpers | |
extend T::Generic | |
interface! | |
sealed! | |
ValueType = type_member | |
ErrorType = type_member | |
sig { | |
type_parameters(:V) | |
.params(value: T.all(T.type_parameter(:V), Object)) | |
.returns(Result[ | |
T.all(T.type_parameter(:V), Object), | |
T.noreturn, # is this an approximation of the `never` type? | |
]) | |
} | |
def self.ok(value) | |
Success.new(value) | |
end | |
sig { | |
type_parameters(:V) | |
.params(value: T.all(T.type_parameter(:V), Object)) | |
.returns(Result[ | |
T.noreturn, | |
T.all(T.type_parameter(:V), Object) | |
]) | |
} | |
def self.err(value) | |
Failure.new(value) | |
end | |
sig { abstract.returns(ValueType) } | |
def unwrap; end | |
sig { | |
abstract | |
.type_parameters(:U) | |
.params(block: T.proc.params(arg0: ValueType).returns(T.all(T.type_parameter(:U), Object))) | |
.returns(Result[ | |
T.all(T.type_parameter(:U), Object), | |
ErrorType, | |
]) | |
} | |
def map(&block); end | |
class Success | |
extend T::Sig | |
extend T::Generic | |
include Result | |
ValueType = type_member | |
ErrorType = type_member | |
sig { params(value: ValueType).void } | |
def initialize(value) | |
@value = value | |
end | |
sig { override.returns(ValueType) } | |
def unwrap | |
@value | |
end | |
sig { | |
override | |
.type_parameters(:U) | |
.params(block: T.proc.params(arg0: ValueType).returns(T.all(T.type_parameter(:U), Object))) | |
.returns(Result[ | |
T.all(T.type_parameter(:U), Object), | |
ErrorType, | |
]) | |
} | |
def map(&block) | |
c = block.call(@value) | |
Result.ok(c) | |
end | |
end | |
class Failure | |
extend T::Sig | |
extend T::Generic | |
include Result | |
ValueType = type_member | |
ErrorType = type_member | |
sig { params(value: ErrorType).void } | |
def initialize(value) | |
@value = value | |
end | |
sig { override.returns(T.noreturn) } | |
def unwrap | |
raise UnwrapError.new(@value) | |
end | |
sig { | |
override | |
.type_parameters(:U) | |
.params(block: T.proc.params(arg0: ValueType).returns(T.all(T.type_parameter(:U), Object))) | |
.returns(Result[ | |
T.all(T.type_parameter(:U), Object), | |
ErrorType, | |
]) | |
} | |
def map(&block) | |
Result.err(@value) | |
end | |
end | |
class UnwrapError < StandardError | |
extend T::Sig | |
sig { params(value: T.untyped).void } | |
def initialize(value) | |
@value = value | |
end | |
sig { returns(String) } | |
def message | |
"called `Result::unwrap` on a Failure containing: '#{@value}'" | |
end | |
end | |
end |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment