MutableHashTable

MutableHashTable -- the class of all mutable hash tables.

A mutable hash table is a type of hash table whose entries can be changed.

Normally the entries in a mutable hash table are not printed, to prevent infinite loops in the printing routines. To print them out, use peek.

     i1 = x = new MutableHashTable
     
     o1 = MutableHashTable{...}
     
     o1 : MutableHashTable

     i2 = scan(0 .. 30, i -> x#i = i^2)

     i3 = x # 20
     
     o3 = 400

     i4 = x #? 40
     
     o4 = false