Dictionaries
Author(s): The CLIP Group.
This module provides predicates for implementing dictionaries. Such dictionaries are currently implemented as ordered binary trees of key-value pairs.
Usage and interface
- Library usage:
:- use_module(library(dict)). - Exports:
- Predicates:
dictionary/5, dic_node/2, dic_lookup/3, dic_lookup/4, dic_get/3, dic_replace/4. - Regular Types:
dictionary/1, old_or_new/1, non_empty_dictionary/1.
- Predicates:
- Imports:
- Packages:
prelude, nonpure, assertions, nortchecks, isomodes.
- Packages:
Documentation on exports
PREDICATE
Usage:dictionary(D,K,V,L,R)
The dictionary node D has key K, value V, left child L, and right child R.
- The following properties should hold upon exit:
(dict:non_empty_dictionary/1)D is a non-empty dictionary.
PREDICATE
Usage:dic_node(D,N)
N is a sub-dictionary of D.
- The following properties should hold at call time:
(dict:non_empty_dictionary/1)D is a non-empty dictionary. - The following properties should hold upon exit:
(dict:dictionary/1)N is a dictionary.
PREDICATE
Usage:dic_lookup(D,K,V)
D contains value V at key K. If it was not already in D it is added.
- The following properties should hold upon exit:
(dict:non_empty_dictionary/1)D is a non-empty dictionary.
PREDICATE
Usage:dic_lookup(D,K,V,O)
Same as dic_lookup(D,K,V). O indicates if it was already in D (old) or not (new).
- The following properties should hold upon exit:
(dict:non_empty_dictionary/1)D is a non-empty dictionary.
(dict:old_or_new/1)dict:old_or_new(O)
PREDICATE
Usage:dic_get(D,K,V)
D contains value V at key K. Fails if it is not already in D.
- The following properties should hold at call time:
(term_typing:nonvar/1)D is currently a term which is not a free variable.
(dict:dictionary/1)D is a dictionary. - The following properties should hold upon exit:
(dict:non_empty_dictionary/1)D is a non-empty dictionary.
PREDICATE
Usage:dic_replace(D,K,V,D1)
D and D1 are identical except for the element at key K, which in D1 contains value V, whatever has (or whether it is) in D.
- The following properties should hold at call time:
(dict:dictionary/1)D is a dictionary.
(dict:dictionary/1)D1 is a dictionary. - The following properties should hold upon exit:
(dict:dictionary/1)D is a dictionary.
(dict:dictionary/1)D1 is a dictionary.
Known bugs and planned improvements
- Run-time checks have been reported not to work with this code. That means that either the assertions here, or the code that implements the run-time checks are erroneous.
