Data.MemoCombinators

This module provides combinators for building memo tables over various data types, so that the type of table can be customized depending on the application.

Documentation

type Memo a = forall r. (a -> r) -> a -> r

The type of a memo table.

memo2 :: Memo a -> Memo b -> (a -> b -> r) -> a -> b -> r

Memoize a two argument function (just apply the table directly for single argument functions).

memo3 :: Memo a -> Memo b -> Memo c -> (a -> b -> c -> r) -> a -> b -> c -> r

Memoize a three argument function.

memoSecond :: Memo b -> (a -> b -> r) -> a -> b -> r

Memoize the second argument of a function.

memoThird :: Memo c -> (a -> b -> c -> r) -> a -> b -> c -> r

Memoize the third argument of a function.

bool :: Memo Bool

A memo table for bools.

type RangeMemo a = a -> a -> Memo a

The type of builders for ranged tables; takes a lower bound and an upper bound, and returns a memo table for that range. The table's behavior is undefined for values outside that range.

arrayRange :: Ix a => RangeMemo a

Build a memo table for a range using a flat array.

chunks :: Ix a => RangeMemo a -> [(a, a)] -> Memo a

Given a list of ranges, (lazily) build a memo table for each one and combine them using linear search.