Guile Reference Manual
22.7.3 Hash Tables
Hash tables are dictionaries which offer similar functionality as
association lists: They provide a mapping from keys to values. The
difference is that association lists need time linear in the size of
elements when searching for entries, whereas hash tables can normally
search in constant time. The drawback is that hash tables require a
little bit more memory, and that you can not use the normal list
procedures (see section 22.2 Lists) for working with them.
