Parametric polymorphism: Difference between revisions

=={{header|C++}}==

 

class tree

{

public:

void replace_all (T new_value);

 

For simplicity, we replace all values in the tree with a new value:

 

void tree<T>::replace_all (T new_value)

{

left->replace_all (new_value);

right->replace_all (new_value);

=={{header|D}}==

D template can parametric by constant.

 

class ArrayTree(T, int LEN) {

if(RHS) RHS.map(dg) ;

}

This is a using example.

module polytest ;

import std.stdio ;

import parapoly ;

//Instantiating an ArrayTree class of real(T) array, whose length(LEN) is 3.

alias ArrayTree!(real, 3) VecT ;

void main() {

VecT v = new VecT(0.01);

writefln() ;

v.map((real[] x){writefln(x) ;} ) ;

=={{header|Haskell}}==

 

 

mapTree :: (a -> b) -> Tree a -> Tree b

mapTree f Empty = Empty

 

=={{header|Java}}==

Following the C++ example:

private T value;

private Tree<T> left;

right.replaceAll(value);

}

 

=={{header|OCaml}}==

 

 

(** val map_tree : ('a -> 'b) -> 'a tree -> 'b tree *)

let rec map_tree f = function

| Empty -> Empty

 

=={{header|Standard ML}}==

 

 

(** val map_tree = fn : ('a -> 'b) -> 'a tree -> 'b tree *)

fun map_tree f Empty = Empty