java.lang.Object
- com.google.errorprone.refaster.Choice<T>

```
public abstract class Choice<T>
extends Object
```
A representation of a choice with zero or more options, which may be evaluated lazily or strictly.
This resembles the list monad in Haskell.

Author:

[email protected] (Louis Wasserman)

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`static <T> Choice<T>`	`any(Collection<Choice<T>> choices)`	Returns a choice between any of the options from any of the specified choices.
`Choice<T>`	`condition(boolean condition)`	Returns this choice if `condition`, otherwise the empty choice.
`static <T> Choice<T>`	`condition(boolean condition, T t)`	Returns a `Choice` with `t` as an option if `condition`, and no options otherwise.
`Choice<T>`	`condition(com.google.common.base.Predicate<? super T> predicate)`	Filters the choices to those that satisfy the provided `Predicate`.
`com.google.common.base.Optional<T>`	`first()`	Returns the first valid option from this `Choice`.
`static <T> Choice<T>`	`from(Collection<T> choices)`
`static <T> Choice<T>`	`fromOptional(com.google.common.base.Optional<T> optional)`	Returns a choice of the optional value, if it is present, or the empty choice if it is absent.
`protected abstract Iterator<T>`	`iterator()`
`static <T> Choice<T>`	`none()`	The empty `Choice`.
`static <T> Choice<T>`	`of(T t)`	Returns a `Choice` with only one option, `t`.
`Choice<T>`	`or(Choice<T> other)`	Returns a choice of the options from this `Choice` or from `other`.
`<R> Choice<R>`	`thenChoose(com.google.common.base.Function<? super T,Choice<R>> function)`	Returns all the choices obtained by choosing from this `Choice` and then choosing from the `Choice` yielded by this function on the result.
`<R> Choice<R>`	`thenOption(com.google.common.base.Function<? super T,com.google.common.base.Optional<R>> function)`	Returns all the choices obtained by choosing from this `Choice` and yielding a present `Optional`.
`String`	`toString()`
`<R> Choice<R>`	`transform(com.google.common.base.Function<? super T,R> function)`	Maps the choices with the specified function.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Method Detail
  - none
```
public static <T> Choice<T> none()
```
    The empty Choice.
  - of
```
public static <T> Choice<T> of(T t)
```
    Returns a Choice with only one option, t.
  - condition
```
public static <T> Choice<T> condition(boolean condition,
                                      T t)
```
    Returns a Choice with t as an option if condition, and no options otherwise.
  - fromOptional
```
public static <T> Choice<T> fromOptional(com.google.common.base.Optional<T> optional)
```
    Returns a choice of the optional value, if it is present, or the empty choice if it is absent.
  - from
```
public static <T> Choice<T> from(Collection<T> choices)
```
  - any
```
public static <T> Choice<T> any(Collection<Choice<T>> choices)
```
    Returns a choice between any of the options from any of the specified choices.
  - iterator
```
@ForOverride
protected abstract Iterator<T> iterator()
```
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - first
```
public com.google.common.base.Optional<T> first()
```
    Returns the first valid option from this Choice.
  - thenChoose
```
public <R> Choice<R> thenChoose(com.google.common.base.Function<? super T,Choice<R>> function)
```
    Returns all the choices obtained by choosing from this Choice and then choosing from the Choice yielded by this function on the result.
    The function may be applied lazily or immediately, at the discretion of the implementation.
    This is the monadic bind for Choice.
  - thenOption
```
public <R> Choice<R> thenOption(com.google.common.base.Function<? super T,com.google.common.base.Optional<R>> function)
```
    Returns all the choices obtained by choosing from this Choice and yielding a present Optional.
    The function may be applied lazily or immediately, at the discretion of the implementation.
  - transform
```
public <R> Choice<R> transform(com.google.common.base.Function<? super T,R> function)
```
    Maps the choices with the specified function.
  - or
```
public Choice<T> or(Choice<T> other)
```
    Returns a choice of the options from this Choice or from other.
  - condition
```
public Choice<T> condition(boolean condition)
```
    Returns this choice if condition, otherwise the empty choice.
  - condition
```
public Choice<T> condition(com.google.common.base.Predicate<? super T> predicate)
```
    Filters the choices to those that satisfy the provided Predicate.

Class Choice<T>

Method Summary

Methods inherited from class java.lang.Object

Method Detail

none

of

condition

fromOptional

from

any

iterator

toString

first

thenChoose

thenOption

transform

or

condition

condition