Functional Java

https://javadoc.io/doc/org.functionaljava/functionaljava/5.0
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### Create an Iso using get and reverseGet functions

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Iso.html

Use the `iso` factory method to create an Iso by providing functions for getting the target value and setting the source value.

```java
public static <S,A> Iso<S,A> iso(F<S,A> get,    F<A,S> reverseGet)
```

--------------------------------

### Create Iso from Functions

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Iso.html

Creates an Iso using a pair of functions: one to get the target value and one to reverse the operation, getting the source value from the target.

```java
public static
 <S,A> Iso<S,A> iso(F<S,A> get,
                                 F<A,S> reverseGet)
```

--------------------------------

### iso

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Iso.html

Create an Iso using a pair of functions: one to get the target and one to get the source.

```APIDOC
## iso

### Description
Create an `Iso` using a pair of functions: one to get the target and one to get the source.

### Method
public static <S,A> Iso<S,A> iso(F<S,A> get, F<A,S> reverseGet)
```

--------------------------------

### Get Sublists

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/NonEmptyList.html

Generates a NonEmptyList where each element is a sublist of the original list, starting from each possible position. For example, `NonEmptyList(1, 2, 3)` would yield `NonEmptyList(NonEmptyList(1, 2, 3), NonEmptyList(2, 3), NonEmptyList(3))`.

```java
NonEmptyList<NonEmptyList<A>> sublists()
```

--------------------------------

### Show Instance for Short

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for java.lang.Short.

```java
public static final	Show<java.lang.Short> shortShow
```

--------------------------------

### Get Subsequence

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/LazyString.html

Gets the specified subsequence of this LazyString between the given start (inclusive) and end (exclusive) indices. Returns a CharSequence.

```java
java.lang.CharSequence
subSequence(int
start,
int
end)
```

--------------------------------

### Show Instance for String

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for java.lang.String.

```java
public static final	Show<java.lang.String> stringShow
```

--------------------------------

### Get all prefixes of a stream

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/Stream.html

Use `inits` to obtain a stream of all prefixes of the original stream, starting with the stream itself. This is helpful for prefix-based analysis.

```java
public final	Stream<Stream<A>>	inits()
```

--------------------------------

### Get Plus Function (with value)

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/Enumerator.html

Returns a function that moves a value along the enumerator a given number of times, starting from a specified value.

```java
public	F<java.lang.Long,Option<A>>	plus(A	a)
```

--------------------------------

### asOptional

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/index-all.html

Views an Iso as an Optional.

```APIDOC
## asOptional()

### Description
Views an `Iso` as a `Optional`.

### Method
Method

### Endpoint
N/A (Java method)

### Parameters
None explicitly documented for this signature.

### Request Example
N/A

### Response
N/A
```

```APIDOC
## asOptional()

### Description
Views a `Lens` as an `Optional`.

### Method
Method

### Endpoint
N/A (Java method)

### Parameters
None explicitly documented for this signature.

### Request Example
N/A

### Response
N/A
```

--------------------------------

### Get First Few Elements of a Finger Tree

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/fingertrees/Deep.html

Retrieves the initial elements of the finger tree. This is useful for peeking at the start of the sequence without modifying the tree.

```java
public
Digit<V,A> prefix()
```

--------------------------------

### Method _1

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/P1.html

Accesses the first element of the product.

```APIDOC
## Method _1

```java
public abstract A _1()
```

### Description
Accesses the first (and only) element of the product represented by P1.

Returns:
    The first element of the product.
```

--------------------------------

### Get Tails

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/NonEmptyList.html

Generates a NonEmptyList where each element is a tail of the original list, starting from each possible position. This is similar to `sublists` but typically refers to the remaining part of the list after a certain point.

```java
NonEmptyList<NonEmptyList<A>> tails()
```

--------------------------------

### Show instance for P2 (Customizable)

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Creates a Show instance for the P2 (tuple-2) type with customizable start, separator, and end strings. Requires Show instances for both elements.

```java
public static <A,B> Show<P2<A,B>> p2Show(Show<A> sa,
                                         Show<B> sb,
                                         java.lang.String start,
                                         java.lang.String sep,
                                         java.lang.String end)
```

--------------------------------

### Show Instance for BitSet

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for java.util.BitSet.

```java
public static final	Show<BitSet> bitSetShow
```

--------------------------------

### Get First-Class Get Method

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/TreeMap.html

Returns a first-class function version of the get method for this TreeMap.

```java
F<K,Option<V>> get()
```

--------------------------------

### Method Summary - Instance Methods

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/Option.html

Details the instance methods available on an Option object, including applying functions, binding, and creating arrays.

```APIDOC
## Method Summary - Instance Methods

| Modifier and Type | Method and Description |
|---|---|
| `<B> Option<B>` | `apply(Option<F<A,B>> of)` Performs function application within an optional value (applicative functor pattern). |
| `A[]` | `array(java.lang.Class<A[]> c)` Returns an array from this optional value. |
| `<B> Option<B>` | `bind(F<A,Option<B>> f)` Binds the given function across the element of this optional value with a final join. |
| `<B,C> Option<C>` | `bind(Option<B> ob,     F<A,F<B,C>> f)` Binds the given function across the element of this optional value and the given optional value with a final join. |
| `<B,C,D> Option<D>` | `bind(Option<B> ob,     Option<C> oc,     F<A,F<B,F<C,D>>> f)` Binds the given function across the element of this optional value and the given optional value with a final join. |
| `<B,C,D,E> Option<E>` | `bind(Option<B> ob,     Option<C> oc,     Option<D> od,     F<A,F<B,F<C,F<D,E>>>> f)` Binds the given function across the element of this optional value and the given optional value with a final join. |
| `<B,C,D,E,F$>  Option<F$>` | `bind(Option<B> ob,     Option<C> oc,     Option<D> od,     Option<E> oe,     F<A,F<B,F<C,F<D,F<E,F$>>>>> f)` Binds the given function across the element of this optional value and the given optional value with a final join. |
| `<B,C,D,E,F$,G>  Option<G>` | `bind(Option<B> ob,     Option<C> oc,     Option<D> od,     Option<E> oe,     Option<F$> of,     F<A,F<B,F<C,F<D,F<E,F<F$,G>>>>>> f)` Binds the given function across the element of this optional value and the given optional value with a final join. |
| `<B,C,D,E,F$,G,H>  Option<H>` | `bind(Option<B> ob,     Option<C> oc,     Option<D> od,     Option<E> oe,     Option<F$> of,     Option<G> og,     F<A,F<B,F<C,F<D,F<E,F<F$,F<G,H>>>>>>> f)` Binds the given function across the element of this optional value and the given optional value with a final join. |
| `<B,C,D,E,F$,G,H,I>  Option<I>` | `bind(Option<B> ob,     Option<C> oc,     Option<D> od,     Option<E> oe,     Option<F$> of,     Option<G> og,     Option<H> oh,     F<A,F<B,F<C,F<D,F<E,F<F$,F<G,F<H,I>>>>>>>> f)` Binds the given function across the element of this optional value and the given optional value with a final join. |
| `<B> Option<P2<A,B>>` | `bindProduct(Option<B> ob)` |
| `<B,C> Option<P3<A,B,C>>` | `bindProduct(Option<B> ob,            Option<C> oc)` |
| `<B,C,D> Option<P4<A,B,C,D>>` | `bindProduct(Option<B> ob,            Option<C> oc,            Option<D> od)` |
| `<B,C,D,E> Option<P5<A,B,C,D,E>>` | `bindProduct(Option<B> ob,            Option<C> oc,            Option<D> od,            Option<E> oe)` |
| `<B,C,D,E,F$>  Option<P6<A,B,C,D,E,F$>>` | `bindProduct(Option<B> ob,            Option<C> oc,            Option<D> od,            Option<E> oe,            Option<F$> of)` |
```

--------------------------------

### Create Product-7 Instance

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/P.html

Creates an instance of a product-7 by taking seven elements. This is a direct way to form a 7-element tuple.

```java
public static	<A,B,C,D,E,F$,G> P7<A,B,C,D,E,F$,G> p(A a,
                                                    B b,
                                                    C c,
                                                    D d,
                                                    E e,
                                                    F$ f,
                                                    G g)
```

--------------------------------

### Get or Modify with PPrism

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/PPrism.html

Get the target of a PPrism, or modify the source if the target is not present. Returns an Either type.

```java
abstract Either<T,A> getOrModify(S s)
```

--------------------------------

### Get Option from PPrism

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/PPrism.html

Safely get the target of a PPrism. Returns an Option, which is None if the prism does not match the source.

```java
abstract Option<A> getOption(S s)
```

--------------------------------

### View an Iso as an Optional

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Iso.html

Use `asOptional` to treat an Iso as an Optional. This can be useful when the Iso's transformation might not always succeed or is optional in nature.

```java
Optional<S,A> asOptional()
```

--------------------------------

### Get File Contents

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/IO.html

A static method that returns an IO action to get the contents of a file. The result is a LazyString.

```java
static
IO<LazyString>
getContents()
```

--------------------------------

### Create Product-5 Instance

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/P.html

Creates an instance of a product-5 by taking five elements. This is a direct way to form a 5-element tuple.

```java
public static	<A,B,C,D,E> P5<A,B,C,D,E> p(A a,
                                          B b,
                                          C c,
                                          D d,
                                          E e)
```

--------------------------------

### F0 Interface Method Detail: get()

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/F0.html

Details the default 'get()' method of the F0 interface, inherited from java.util.function.Supplier.

```java
default A get()

Specified by:
    get in interface java.util.function.Supplier<A>
```

--------------------------------

### View an Iso as a Lens

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Iso.html

The `asLens` method provides a view of the Iso as a Lens, allowing it to be used in contexts expecting a Lens.

```java
Lens<S,A> asLens()
```

--------------------------------

### Starts With Substring

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/LazyString.html

Checks if this LazyString starts with the given LazyString. Returns true if it's a prefix, false otherwise.

```java
boolean startsWith(LazyString
cs)
```

--------------------------------

### View an Iso as a Prism

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Iso.html

The `asPrism` method allows an Iso to be viewed as a Prism. This is helpful when you need to use Prism-specific operations.

```java
Prism<S,A> asPrism()
```

--------------------------------

### Get subsequence

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/LazyString.html

Gets the specified subsequence of this lazy string. Handles out-of-bounds indexes gracefully by returning an empty or truncated sequence.

```java
public	java.lang.CharSequence	subSequence(int	start,
                                          int	end)
```

--------------------------------

### inits

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/List.html

Returns the list of initial segments of this list, shortest first.

```APIDOC
## inits

### Description
Returns the list of initial segments of this list, shortest first.

### Method
public final List<List<A>> inits()

### Returns
The list of initial segments of this list, shortest first.
```

--------------------------------

### pIso

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/PIso.html

Creates a PIso using a pair of functions: one to get the target value and one to get the source value from the target.

```APIDOC
## pIso

### Description
Creates a `PIso` using a pair of functions: one to get the target and one to get the source.

### Method
public static <S,T,A,B> PIso<S,T,A,B> pIso(F<S,A> get, F<B,T> reverseGet)

### Parameters
* **get** (F<S,A>) - Function to get the target value.
* **reverseGet** (F<B,T>) - Function to get the source value from the target.
```

--------------------------------

### Show Instance for StringBuilder

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for java.lang.StringBuilder.

```java
public static final	Show<java.lang.StringBuilder> stringBuilderShow
```

--------------------------------

### on (static)

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Ord.html

Begin definition of an ord instance. This is a static helper for creating Ord instances.

```APIDOC
## on (static)

### Description
Begin definition of an ord instance. See Also: `Equal.Definition.then(F, Equal)`

### Method
public static <A,B> Ord.Definition<A> on(F<A,B> f, Ord<B> ord)

### Parameters
- `f` (F<A,B>) - The function to map.
- `ord` (Ord<B>) - The Ord instance to use for the mapped type.

### Response
- An `Ord.Definition` for type A.
```

--------------------------------

### Get the target value from an Iso

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Iso.html

The `get` method extracts the target value (type A) from the source value (type S) using the Iso.

```java
public A get(S s)
```

--------------------------------

### Starts With Check

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/LazyString.html

A first-class function for checking if a LazyString starts with another LazyString. Returns a function that takes a LazyString and returns a boolean.

```java
static F<LazyString,F<LazyString,java.lang.Boolean>> startsWith()
```

--------------------------------

### Show instance for P2 (Map style)

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Creates a Show instance for the P2 (tuple-2) type, formatted like a map. Requires Show instances for both elements.

```java
public static <A,B> Show<P2<A,B>> p2MapShow(Show<A> sa,
                                            Show<B> sb)
```

--------------------------------

### v6Show

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for V6, requiring a Show instance for its elements.

```APIDOC
## v6Show

### Description
A show instance for a vector-6.

### Parameters
* `ea` (Show<A>) - A show for the elements of the vector.

### Returns
Show<V6<A>> - A show instance for a vector-6.
```

--------------------------------

### Get Seventh Element as Function

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/vector/V7.html

A first-class function to get the seventh element of a vector. This provides a functional way to access the seventh element.

```java
static <A> F<V7<A>,A> __7()
```

--------------------------------

### Show Instance for Streams (split into lines)

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for streams that splits into lines. Requires a Show instance for the stream elements.

```java
public static <A> Show<Stream<A>> unlineShow(Show<A> sa)
```

--------------------------------

### Get Sixth Element as Function

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/vector/V7.html

A first-class function to get the sixth element of a vector. This provides a functional way to access the sixth element.

```java
static <A> F<V7<A>,A> __6()
```

--------------------------------

### Create a Product-1 with an Element

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/P.html

Creates a product-1 by providing a single element. This is a convenience method for constructing a P1 instance.

```java
public static <A> P1<A> p(A a)

```

--------------------------------

### Curried Get Method

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/HashMap.html

Provides a curried version of the get method, returning a function that takes a key and returns an Option of the value. Useful for functional composition.

```java
public
 F<K,Option<V>> get()
```

--------------------------------

### Show instance for Stream (Customizable)

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Creates a Show instance for the Stream type with customizable start, separator, and end strings. Requires a Show instance for its elements.

```java
public static <A> Show<Stream<A>> streamShow(Show<A> sa,
                                             java.lang.String start,
                                             java.lang.String sep,
                                             java.lang.String end)
```

--------------------------------

### intShow

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

A show instance for the int type.

```APIDOC
## intShow

### Description
A show instance for the `int` type.

### Field Detail
`public static final Show<java.lang.Integer> intShow`
```

--------------------------------

### Create Java Identifier Start Parser (F0)

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/parser/Parser.CharsParser.html

Returns a parser that produces a Java identifier start character. Use this to parse the initial character of a Java identifier.

```java
public static <E> Parser<Stream<java.lang.Character>, java.lang.Character, E> javaIdentifierStart(F0<E> missing,
                                                                                                F<java.lang.Character, E> sat)
```

--------------------------------

### v7Show

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for V7, requiring a Show instance for its elements.

```APIDOC
## v7Show

### Description
A show instance for a vector-7.

### Parameters
* `ea` (Show<A>) - A show for the elements of the vector.

### Returns
Show<V7<A>> - A show instance for a vector-7.
```

--------------------------------

### Instance Method to Get State

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/State.html

The instance 'gets' method returns a State action that retrieves the current state. This is a convenience method for accessing the state within a State computation.

```java
public State<S,S> gets()
```

--------------------------------

### p7Equal

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Equal.html

Creates an Equal instance for a product-7, which is a tuple of seven elements. It requires an Equal instance for each element of the product.

```APIDOC
## p7Equal

### Description
Creates an Equal instance for a product-7.

### Method
static

### Signature
public static <A,B,C,D,E,F$,G> Equal<P7<A,B,C,D,E,F$,G>> p7Equal(Equal<A> ea, Equal<B> eb, Equal<C> ec, Equal<D> ed, Equal<E> ee, Equal<F$> ef, Equal<G> eg)

### Parameters
* **ea** (Equal<A>) - Equality across the first element of the product.
* **eb** (Equal<B>) - Equality across the second element of the product.
* **ec** (Equal<C>) - Equality across the third element of the product.
* **ed** (Equal<D>) - Equality across the fourth element of the product.
* **ee** (Equal<E>) - Equality across the fifth element of the product.
* **ef** (Equal<F$>) - Equality across the sixth element of the product.
* **eg** (Equal<G>) - Equality across the seventh element of the product.

### Returns
An equal instance for a product-7.
```

--------------------------------

### Get a Value from the State

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/State.html

The static 'gets' method creates a State that extracts a specific value from the current state using a provided function. It allows you to read parts of the state.

```java
public static <S,A> State<S,A> gets(F<S,A> f)
```

--------------------------------

### Method __1

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/P1.html

Returns a function that returns the first element of a product.

```APIDOC
## Method __1

```java
public static <A> F<P1<A>,A> __1()
```

### Description
Returns a function that, when applied to a P1, returns its first element.

Returns:
    A function that extracts the first element from a P1.
```

--------------------------------

### Create PLens from Get and Set Functions

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/PLens.html

Create a PLens using a pair of functions: one to get the target value and one to set it. This is a common way to define custom lenses.

```java
static <S,T,A,B> PLens<S,T,A,B> pLens(F<S,A> get, F<B,F<S,T>> set)
```

--------------------------------

### Show Instance for StringBuffer

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for java.lang.StringBuffer.

```java
public static final	Show<java.lang.StringBuffer> stringBufferShow
```

--------------------------------

### Create Java Identifier Start Parser (E)

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/parser/Parser.CharsParser.html

Returns a parser that produces a Java identifier start character. This overload allows specifying the missing character error using a generic type E.

```java
public static <E> Parser<Stream<java.lang.Character>, java.lang.Character, E> javaIdentifierStart(E missing,
                                                                                                F<java.lang.Character, E> sat)
```

--------------------------------

### v5Show

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for V5, requiring a Show instance for its elements.

```APIDOC
## v5Show

### Description
A show instance for a vector-5.

### Parameters
* `ea` (Show<A>) - A show for the elements of the vector.

### Returns
Show<V5<A>> - A show instance for a vector-5.
```

--------------------------------

### asOptional

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Iso.html

View an Iso as an Optional. This method is an override from the PIso class.

```APIDOC
## asOptional

### Description
View an `Iso` as an `Optional`.

### Method
public Optional<S,A> asOptional()

### Overrides
`asOptional` in class `PIso<S,S,A,A>`
```

--------------------------------

### reverseGet

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Prism.html

Gets the modified source of a PPrism.

```APIDOC
## reverseGet

### Description
Gets the modified source of a PPrism.

### Method
`S reverseGet(A a)`

### Returns
The modified source.
```

--------------------------------

### Static Method: on(F<A,B> f, Equal<B> eq)

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Equal.html

Begins the definition of an Equal instance.

```APIDOC
## Static Method: on(F<A,B> f, Equal<B> eq)

### Description
Begin definition of an equal instance.

### Method Signature
`public static <A,B> Equal.Definition<A> on(F<A,B> f, Equal<B> eq)`

### Parameters
#### Path Parameters
* **f** (F<A,B>) - Required - The function to map.
* **eq** (Equal<B>) - Required - The Equal instance to use.

### Returns
* **Equal.Definition<A>** - An Equal definition.
```

--------------------------------

### Get Ordering

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/Enumerator.html

Returns the ordering for the enumerator.

```java
public	Ord<A>	order()
```

--------------------------------

### Run a State Action and Get State and Value

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/State.html

The 'run' method executes a State action with a given initial state and returns a pair containing the final state and the computed value. This is the primary way to get results from a State.

```java
public P2<S,A> run(S s)
```

--------------------------------

### inits

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/Stream.html

Returns a stream containing all prefixes of the original stream, including the stream itself.

```APIDOC
## inits

### Description
Returns a stream of all prefixes of this stream. A stream is considered a prefix of itself in this context.

### Method
public final Stream<Stream<A>> inits()

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
None

### Response
#### Success Response (200)
- **return value** (Stream<Stream<A>>) - A stream of the prefixes of this stream, starting with the stream itself.

#### Response Example
None
```

--------------------------------

### Show instance for Stream (Basic)

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Creates a basic Show instance for the Stream type, requiring a Show instance for its elements.

```java
public static <A> Show<Stream<A>> streamShow(Show<A> sa)
```

--------------------------------

### Get Empty List

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/List.html

Returns an empty list.

```Java
public static	<A> 	List<A> 	nil()
```

--------------------------------

### getOption

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Optional.html

Get the target of a POptional or nothing if there is no target.

```APIDOC
## getOption

### Description
Get the target of a POptional or nothing if there is no target.

### Method
public Option<A> getOption(S s)

### Parameters
* **s** (S) - The source value to check.
```

--------------------------------

### priorityQueueShow

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Creates a Show instance for PriorityQueue, requiring Show instances for keys and values.

```APIDOC
## priorityQueueShow

### Description
Creates a Show instance for PriorityQueue.

### Parameters
* `sk` (Show<K>) - Show for the keys.
* `sv` (Show<V>) - Show for the values.

### Returns
Show<PriorityQueue<K,V>> - A show instance for PriorityQueue.
```

--------------------------------

### p7Hash

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Hash.html

Creates a hash instance for a product-7. It takes seven Hash instances as input, each corresponding to an element of the product.

```APIDOC
## p7Hash

### Description
Creates a hash instance for a product-7.

### Method
static <A,B,C,D,E,F$,G> Hash<P7<A,B,C,D,E,F$,G>> p7Hash(Hash<A> ha, Hash<B> hb, Hash<C> hc, Hash<D> hd, Hash<E> he, Hash<F$> hf, Hash<G> hg)

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Parameters
- **ha** (Hash<A>) - A hash for the first element of the product.
- **hb** (Hash<B>) - A hash for the second element of the product.
- **hc** (Hash<C>) - A hash for the third element of the product.
- **hd** (Hash<D>) - A hash for the fourth element of the product.
- **he** (Hash<E>) - A hash for the fifth element of the product.
- **hf** (Hash<F$>) - A hash for the sixth element of the product.
- **hg** (Hash<G>) - A hash for the seventh element of the product.

### Response
#### Success Response (200)
A hash instance for a product-7.

#### Response Example
None provided.
```

--------------------------------

### getOption

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Prism.html

Gets the target of a PPrism or nothing if there is no target.

```APIDOC
## getOption

### Description
Gets the target of a PPrism or nothing if there is no target.

### Method
`Option<A> getOption(S s)`

### Returns
An Option containing the target, or None if no target exists.
```

--------------------------------

### length

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/fingertrees/Digit.html

Abstract method to get the length of the digit.

```APIDOC
## length

### Description
Abstract method to get the length of the digit.

### Method
public abstract int length()
```

--------------------------------

### Create Product-6 Instance

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/P.html

Creates an instance of a product-6 by taking six elements. This is a direct way to form a 6-element tuple.

```java
public static	<A,B,C,D,E,F$> P6<A,B,C,D,E,F$> p(A a,
                                                B b,
                                                C c,
                                                D d,
                                                E e,
                                                F$ f)
```

--------------------------------

### fj.data.IO.getContents()

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/index-all.html

Static method to get the contents of an IO operation.

```APIDOC
## fj.data.IO.getContents()

### Description
Static method to get the contents of an IO operation.

### Method
GET (conceptual)

### Endpoint
N/A (Method Call)

### Parameters
N/A

### Request Example
N/A

### Response
N/A
```

--------------------------------

### take

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/Seq.html

Returns a sequence consisting of the first n elements of this sequence, or else the whole sequence, if it has less than n elements.

```APIDOC
## take

### Description
The `take` method returns a new sequence containing the first `n` elements from the original sequence. If the original sequence has fewer than `n` elements, the entire sequence is returned.

### Method Signature
```java
public Seq<A> take(int n)
```

### Parameters
* `n` (int) - The maximum number of elements to take from this sequence.
```

--------------------------------

### Create Product-3 Instance

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/P.html

Creates an instance of a product-3 by taking three elements. This is a direct way to form a 3-element tuple.

```java
public static	<A,B,C> P3<A,B,C> p(A a,
                                  B b,
                                  C c)
```

--------------------------------

### length_

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/List.html

Provides a first-class function to get the length of a list.

```APIDOC
## length_

### Description
First-class length. Returns a function that gets the length of a given list.

### Method
public static <A> F<List<A>, Integer> length_()

### Returns
A function that gets the length of a given list.
```

--------------------------------

### __5()

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/vector/V7.html

A first-class function to get the fifth element of a vector.

```APIDOC
## __5()

### Description
A first-class function to get the fifth element of a vector.

### Method
public static <A> F<V7<A>,A> __5()

### Returns
a function that gets the fifth element of a given vector.
```

--------------------------------

### p6Hash

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Hash.html

Creates a hash instance for a product-6. It takes six Hash instances as input, each corresponding to an element of the product.

```APIDOC
## p6Hash

### Description
Creates a hash instance for a product-6.

### Method
static <A,B,C,D,E,F$> Hash<P6<A,B,C,D,E,F$>> p6Hash(Hash<A> ha, Hash<B> hb, Hash<C> hc, Hash<D> hd, Hash<E> he, Hash<F$> hf)

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Parameters
- **ha** (Hash<A>) - A hash for the first element of the product.
- **hb** (Hash<B>) - A hash for the second element of the product.
- **hc** (Hash<C>) - A hash for the third element of the product.
- **hd** (Hash<D>) - A hash for the fourth element of the product.
- **he** (Hash<E>) - A hash for the fifth element of the product.
- **hf** (Hash<F$>) - A hash for the sixth element of the product.

### Response
#### Success Response (200)
A hash instance for a product-6.

#### Response Example
None provided.
```

--------------------------------

### Create a Product-2 with Elements

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/P.html

Creates a product-2 by providing two elements. This is a convenience method for constructing a P2 instance.

```java
public static <A,B> P2<A,B> p(A a,
                              B b)

```

--------------------------------

### __4()

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/vector/V7.html

A first-class function to get the fourth element of a vector.

```APIDOC
## __4()

### Description
A first-class function to get the fourth element of a vector.

### Method
public static <A> F<V7<A>,A> __4()

### Returns
a function that gets the fourth element of a given vector.
```

--------------------------------

### __4

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/vector/V6.html

A first-class function to get the fourth element of a vector.

```APIDOC
## __4

### Description
A first-class function to get the fourth element of a vector.

### Method
public static <A> F<V6<A>,A> __4()

### Returns
- F<V6<A>,A> - a function that gets the fourth element of a given vector.
```

--------------------------------

### Bind Product with Five Optional Arguments

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/Option.html

Binds this optional value with five other optional values to create a product of their elements.

```java
<B,C,D,E,F$> Option<P6<A,B,C,D,E,F$>> bindProduct(Option<B> ob, Option<C> oc, Option<D> od, Option<E> oe, Option<F$> of)
```

--------------------------------

### __3()

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/vector/V3.html

A first-class function to get the third element of a vector.

```APIDOC
## __3()

### Description
A first-class function to get the third element of a vector.

### Method
public static <A> F<V3<A>,A> __3()

### Returns
a function that gets the third element of a given vector.
```

--------------------------------

### ShowS Method for String

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Returns the display rendering of the given argument as a String. This is a common way to represent showable values.

```java
public	java.lang.String	showS(A a)
```

--------------------------------

### v2Show

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for V2, requiring a Show instance for its elements.

```APIDOC
## v2Show

### Description
A show instance for a vector-2.

### Parameters
* `ea` (Show<A>) - A show for the elements of the vector.

### Returns
Show<V2<A>> - A show instance for a vector-2.
```

--------------------------------

### __2()

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/vector/V3.html

A first-class function to get the second element of a vector.

```APIDOC
## __2()

### Description
A first-class function to get the second element of a vector.

### Method
public static <A> F<V3<A>,A> __2()

### Returns
a function that gets the second element of a given vector.
```

--------------------------------

### __1()

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/vector/V3.html

A first-class function to get the first element of a vector.

```APIDOC
## __1()

### Description
A first-class function to get the first element of a vector.

### Method
public static <A> F<V3<A>,A> __1()

### Returns
a function that gets the first element of a given vector.
```

--------------------------------

### v3Show

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for V3, requiring a Show instance for its elements.

```APIDOC
## v3Show

### Description
A show instance for a vector-3.

### Parameters
* `ea` (Show<A>) - A show for the elements of the vector.

### Returns
Show<V3<A>> - A show instance for a vector-3.
```

--------------------------------

### Show Instance for PriorityQueue

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for a PriorityQueue. Requires Show instances for keys and values.

```java
public static <K,V> Show<PriorityQueue<K,V>> priorityQueueShow(Show<K> sk, Show<V> sv)
```

--------------------------------

### getOrModify

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/optic/Prism.html

Gets the target of a PPrism or modifies the source if there is no target.

```APIDOC
## getOrModify

### Description
Gets the target of a PPrism or modifies the source if there is no target.

### Method
`Either<S,A> getOrModify(S s)`

### Returns
An Either type representing the target or the modified source.
```

--------------------------------

### get

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/TreeMap.html

Returns a potential value that the given key maps to.

```APIDOC
## get

### Description
Returns a potential value that the given key maps to.

### Method
instance

### Parameters
#### Path Parameters
* `k` (K) - Required - The key to look up in the tree map.

### Returns
* `Option<V>` - A potential value for the given key.
```

--------------------------------

### Create Equal instance for Product-7

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Equal.html

Generates an Equal instance for a product-7. Requires an Equal instance for each of the seven elements.

```java
public static 
                                                                 Equal<P7<A,B,C,D,E,F$,G>> 
                                                                 p7Equal(Equal<A> 
                                                                                                 ea,
                                                                                                Equal<B> 
                                                                                                 eb,
                                                                                                Equal<C> 
                                                                                                 ec,
                                                                                                Equal<D> 
                                                                                                 ed,
                                                                                                Equal<E> 
                                                                                                 ee,
                                                                                                Equal<F$> 
                                                                                                 ef,
                                                                                                Equal<G> 
                                                                                                 eg)
```

--------------------------------

### p6Show

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Provides a Show instance for the P6 (tuple-6) type. Requires Show instances for all six elements.

```APIDOC
## p6Show

### Description
A show instance for the `tuple-6` type.

### Method
public static <A,B,C,D,E,F$> Show<P6<A,B,C,D,E,F$>> p6Show(Show<A> sa, Show<B> sb, Show<C> sc, Show<D> sd, Show<E> se, Show<F$> sf)

### Parameters
#### Path Parameters
- **sa** (Show<A>) - Required - Show for the first element of the tuple.
- **sb** (Show<B>) - Required - Show for the second element of the tuple.
- **sc** (Show<C>) - Required - Show for the third element of the tuple.
- **sd** (Show<D>) - Required - Show for the fourth element of the tuple.
- **se** (Show<E>) - Required - Show for the fifth element of the tuple.
- **sf** (Show<F$>) - Required - Show for the sixth element of the tuple.

### Returns
A show instance for the `tuple-6` type.
```

--------------------------------

### Get Size

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/TreeMap.html

Returns the number of entries currently in the TreeMap.

```java
public int size()
```

--------------------------------

### show (static)

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/Show.html

Returns a show instance using the given function.

```APIDOC
## show

### Description
Returns a show instance using the given function.

### Method Signature
`public static <A> Show<A> show(F<A,Stream<Character>> f)`

### Parameters
* `f` (F<A,Stream<Character>>) - Required - The function to use for the returned show instance.

### Returns
`Show<A>` - A show instance.
```

--------------------------------

### Get All Values

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/TreeMap.html

Returns a List of all values present in this TreeMap.

```java
List<V> values()
```

--------------------------------

### Get All Keys

Source: https://javadoc.io/doc/org.functionaljava/functionaljava/5.0/fj/data/TreeMap.html

Returns a List of all keys present in this TreeMap.

```java
List<K> keys()
```
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