Portability | non-portable |
---|---|

Stability | experimental |

Maintainer | Jan Snajder <jan.snajder@fer.hr> |

Safe Haskell | Safe-Inferred |

An interface to genetically programmable expressions.

# Documentation

This typeclass defines an interface to expressions
that can be genetically programmed. The operations that must be
provided by instances of this class are used for the generation
of random individuals as well as crossover and mutation operations.
(An instance for members of the `Data`

typeclass is provided in
GenProg.GenExpr.Data.)

Minimal complete definition: `exchange`

, `nodeMapM`

, `nodeMapQ`

,
and `nodeIndices`

.

exchange :: e -> Int -> e -> Int -> (e, e)Source

Exchanges subtrees of two expressions:
`exchange e1 n1 e2 n2`

replaces the subexpression of `e1`

rooted in node
`n1`

with the subexpression of `e2`

rooted in `n2`

, and vice versa.

nodeMapM :: Monad m => (e -> m e) -> e -> m eSource

Maps a monadic transformation function over the immediate children of the given node.

nodeMapQ :: (e -> a) -> e -> [a]Source

Maps a query function over the immediate children of the given node and returns a list of results.

nodeIndices :: e -> ([Int], [Int])Source

A list of indices of internal (functional) and external (terminal) nodes of an expression.

adjustM :: Monad m => (e -> m e) -> e -> Int -> m eSource

Adjusts a subexpression rooted at the given node by applying a monadic transformation function.

Number of nodes an expression has.

The depth of an expression. Equals 1 for single-node expressions.