Type classes for creating memoized functions.

## Building

This module can be added to your project using Bower.

To work on this project, use `pulp`

:

```
$ pulp build
$ pulp test
```

## Example

The following Fibonacci function implementation is slow, because its call graph grows exponentially in the size of its argument:

```
let fibonacciSlow 0 = 0
fibonacciSlow 1 = 1
fibonacciSlow n = fibonacciSlow (n - 1) +
fibonacciSlow (n - 2)
```

The `memoize`

function can be used to improve the performance of this function, by tabulating intermediate results:

```
let fibonacciSlow 0 = 0
fibonacciSlow 1 = 1
fibonacciSlow n = fibonacci (n - 1) +
fibonacci (n - 2)
fibonacci = memoize $ \n -> fibonacciSlow n
```

Note that `fibonacciSlow`

has been modified to call the faster `fibonacci`

function.

The `memoize`

function can be applied whenever there is a `Tabulate`

instance for the function argument type. This library provides instances of the `Tabulate`

type class for common types, such as `Maybe`

, `Either`

and `Tuple`

.

## Related resources

- Slides: Elegant memoization by Conal Elliott - @conal