- Documentation
- Reference manual
- The SWI-Prolog library
- library(aggregate): Aggregation operators on backtrackable predicates
- library(ansi_term): Print decorated text to ANSI consoles
- library(apply): Apply predicates on a list
- library(assoc): Association lists
- library(broadcast): Broadcast and receive event notifications
- library(charsio): I/O on Lists of Character Codes
- library(check): Consistency checking
- library(clpb): CLP(B): Constraint Logic Programming over Boolean Variables
- library(clpfd): CLP(FD): Constraint Logic Programming over Finite Domains
- library(clpqr): Constraint Logic Programming over Rationals and Reals
- library(csv): Process CSV (Comma-Separated Values) data
- library(dcg/basics): Various general DCG utilities
- library(dcg/high_order): High order grammar operations
- library(debug): Print debug messages and test assertions
- library(dicts): Dict utilities
- library(error): Error generating support
- library(fastrw): Fast reading and writing of terms
- library(gensym): Generate unique symbols
- library(heaps): heaps/priority queues
- library(increval): Incremental dynamic predicate modification
- library(intercept): Intercept and signal interface
- library(iostream): Utilities to deal with streams
- library(listing): List programs and pretty print clauses
- library(lists): List Manipulation
- library(macros): Macro expansion
- library(main): Provide entry point for scripts
- library(nb_set): Non-backtrackable set
- library(www_browser): Open a URL in the users browser
- library(occurs): Finding and counting sub-terms
- library(option): Option list processing
- library(optparse): command line parsing
- library(ordsets): Ordered set manipulation
- library(pairs): Operations on key-value lists
- library(persistency): Provide persistent dynamic predicates
- library(pio): Pure I/O
- library(portray_text): Portray text
- library(predicate_options): Declare option-processing of predicates
- library(prolog_coverage): Coverage analysis tool
- library(prolog_debug): User level debugging tools
- library(prolog_jiti): Just In Time Indexing (JITI) utilities
- library(prolog_trace): Print access to predicates
- library(prolog_versions): Demand specific (Prolog) versions
- library(prolog_xref): Prolog cross-referencer data collection
- library(quasi_quotations): Define Quasi Quotation syntax
- library(random): Random numbers
- library(rbtrees): Red black trees
- library(readutil): Read utilities
- library(record): Access named fields in a term
- library(registry): Manipulating the Windows registry
- library(rwlocks): Read/write locks
- library(settings): Setting management
- library(statistics): Get information about resource usage
- library(strings): String utilities
- library(simplex): Solve linear programming problems
- library(solution_sequences): Modify solution sequences
- library(tables): XSB interface to tables
- library(terms): Term manipulation
- library(thread): High level thread primitives
- library(thread_pool): Resource bounded thread management
- library(ugraphs): Graph manipulation library
- library(url): Analysing and constructing URL
- library(varnumbers): Utilities for numbered terms
- library(yall): Lambda expressions
- The SWI-Prolog library
- Packages
- Reference manual
A.57 library(terms): Term manipulation
- Compatibility
- YAP, SICStus, Quintus. Not all versions of this library define exactly the same set of predicates, but defined predicates are compatible.
Compatibility library for term manipulation predicates. Most predicates in this library are provided as SWI-Prolog built-ins.
- [det]term_size(@Term, -Size)
- True if Size is the size in cells occupied by Term
on the global (term) stack. A cell is 4 bytes on 32-bit machines
and 8 bytes on 64-bit machines. The calculation does take sharing
into account. For example:
?- A = a(1,2,3), term_size(A,S). S = 4. ?- A = a(1,2,3), term_size(a(A,A),S). S = 7. ?- term_size(a(a(1,2,3), a(1,2,3)), S). S = 11.
Note that small objects such as atoms and small integers have a size 0. Space is allocated for floats, large integers, strings and compound terms.
- [semidet]variant(@Term1, @Term2)
- Same as SWI-Prolog
Term1 =@= Term2
. - subsumes_chk(@Generic, @Specific)
- True if Generic can be made equivalent to Specific
without changing Specific.
- deprecated
- Replace by subsumes_term/2.
- subsumes(+Generic, @Specific)
- True if Generic is unified to Specific without
changing
Specific.
- deprecated
- It turns out that calls to this predicate almost always should have used subsumes_term/2. Also the name is misleading. In case this is really needed, one is adviced to follow subsumes_term/2 with an explicit unification.
- [det]term_subsumer(+Special1, +Special2, -General)
- General is the most specific term that is a generalisation of
Special1 and Special2. The implementation can
handle cyclic terms.
- author
- Inspired by LOGIC.PRO by Stephen Muggleton
- Compatibility
- SICStus
- term_factorized(+Term, -Skeleton, -Substiution)
- Is true when Skeleton is Term where all subterms
that appear multiple times are replaced by a variable and Substitution
is a list of Var=Value that provides the subterm at the location Var.
I.e., After unifying all substitutions in Substiutions, Term
==
Skeleton. Term may be cyclic. For example:?- X = a(X), term_factorized(b(X,X), Y, S). Y = b(_G255, _G255), S = [_G255=a(_G255)].
- mapargs(:Goal, ?Term1, ?Term2)
- Term1 and Term2 have the same functor (name/arity)
and for each matching pair of arguments
call(Goal, A1, A2)
is true. - [det]mapsubterms(:Goal, +Term1, -Term2)
- [det]mapsubterms_var(:Goal, +Term1, -Term2)
- Recursively map sub terms of Term1 into subterms of Term2
for every pair for which
call(Goal, ST1, ST2)
succeeds. Procedurably, the mapping for each (sub) term pairT1/T2
is defined as:- If T1 is a variable
- mapsubterms/3 unifies T2 with T1.
- mapsubterms_var/3 treats variables as other terms.
- If
call(Goal, T1, T2)
succeeds we are done. Note that the mapping does not continue in T2. If this is desired, Goal must call mapsubterms/3 explicitly as part of its conversion. - If T1 is a dict, map all values, i.e., the tag and keys are left untouched.
- If T1 is a list, map all elements, i.e., the list structure is left untouched.
- If T1 is a compound, use same_functor/3 to instantiate T2 and recurse over the term arguments left to right.
- Otherwise T2 is unified with T1.
Both predicates are implemented using foldsubterms/5.
- If T1 is a variable
- [semidet]foldsubterms(:Goal3, +Term1, +State0, -State)
- [semidet]foldsubterms(:Goal4, +Term1, ?Term2, +State0, -State)
- The predicate foldsubterms/5
calls
call(Goal4, SubTerm1, SubTerm2, StateIn, StateOut)
for each subterm, including variables, in Term1. If this call fails, StateIn and StateOut are the same. This predicate may be used to map subterms in a term while collecting state about the mapped subterms. The foldsubterms/4 variant does not map the term. - [semidet]same_functor(?Term1, ?Term2)
- [semidet]same_functor(?Term1, ?Term2, -Arity)
- [semidet]same_functor(?Term1, ?Term2, ?Name, ?Arity)
- True when Term1 and Term2 are terms that have the
same functor (Name/Arity). The arguments must be
sufficiently instantiated, which means either Term1 or Term2
must be bound or both Name and Arity must be
bound.
If Arity is 0, Term1 and Term2 are unified with Name for compatibility.
- Compatibility
- SICStus