select(ZZ,HashTable,Function) -- select a limited number of pairs from a hash table

select(ZZ,HashTable,Function) -- select a limited number of pairs from a hash table

Synopsis:

Function: select -- select elements from a list or hash table

Input:

an instance of class ZZ.

an instance of class HashTable.

an instance of class Function.

Output:

an instance of class HashTable.

select(n,v,f) -- select at most n pairs of the hash table v that yield true when the function f is applied to the value.

The hash table should be immutable: to scan the values in a mutable hash table, use scan(values x, f).