/usr/lib/swipl/library/prolog_wrap.pl
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  • swipl
    • library
      • error.pl
      • apply.pl -- Apply predicates on a list
      • lists.pl -- List Manipulation
      • debug.pl
      • broadcast.pl -- Event service
      • socket.pl -- Network socket (TCP and UDP) library
      • predicate_options.pl -- Access and analyse predicate options
      • shlib.pl -- Utility library for loading foreign objects (DLLs, shared objects)
      • option.pl
      • uid.pl -- User and group management on Unix systems
      • unix.pl -- Unix specific operations
      • syslog.pl -- Unix syslog interface
      • thread_pool.pl
      • gensym.pl -- Generate unique symbols
      • settings.pl -- Setting management
      • arithmetic.pl -- Extensible arithmetic
      • main.pl -- Provide entry point for scripts
      • readutil.pl -- Read utilities
      • ssl.pl -- Secure Socket Layer (SSL) library
      • crypto.pl -- Cryptography and authentication library
      • pldoc.pl -- Process source documentation
      • operators.pl -- Manage operators
      • pairs.pl -- Operations on key-value lists
      • prolog_source.pl -- Examine Prolog source-files
      • pengines.pl -- Pengines: Web Logic Programming Made Easy
      • record.pl -- Access compound arguments by name
      • memfile.pl
      • sgml.pl -- SGML, XML and HTML parser
      • quasi_quotations.pl -- Define Quasi Quotation syntax
      • pure_input.pl -- Pure Input from files and streams
      • time.pl -- Time and alarm library
      • uri.pl -- Process URIs
      • solution_sequences.pl -- Modify solution sequences
      • uuid.pl -- Universally Unique Identifier (UUID) Library
      • ordsets.pl -- Ordered set manipulation
      • random.pl -- Random numbers
      • base64.pl -- Base64 encoding and decoding
      • aggregate.pl -- Aggregation operators on backtrackable predicates
      • pcre.pl -- Perl compatible regular expression matching for SWI-Prolog
      • pengines_io.pl -- Provide Prolog I/O for HTML clients
      • sandbox.pl -- Sandboxed Prolog code
      • apply_macros.pl -- Goal expansion rules to avoid meta-calling
      • assoc.pl -- Binary associations
      • prolog_format.pl -- Analyse format specifications
      • yall.pl -- Lambda expressions
      • sha.pl -- SHA secure hashes
      • process.pl -- Create processes and redirect I/O
      • filesex.pl -- Extended operations on files
      • zlib.pl -- Zlib wrapper for SWI-Prolog
      • bdb.pl -- Berkeley DB interface
      • hash_stream.pl -- Maintain a hash on a stream
      • md5.pl -- MD5 hashes
      • porter_stem.pl
      • csv.pl -- Process CSV (Comma-Separated Values) data
      • pprint.pl -- Pretty Print Prolog terms
      • atom.pl -- Operations on atoms
      • ctypes.pl -- Character code classification
      • modules.pl -- Module utility predicates
      • occurs.pl -- Finding and counting sub-terms
      • prolog_xref.pl -- Prolog cross-referencer data collection
      • prolog_colour.pl -- Prolog syntax colouring support.
      • lazy_lists.pl -- Lazy list handling
      • prolog_code.pl -- Utilities for reasoning about code
      • ugraphs.pl -- Graph manipulation library
      • xpath.pl -- Select nodes in an XML DOM
      • iostream.pl -- Utilities to deal with streams
      • doc_http.pl -- Documentation server
      • url.pl -- Analysing and constructing URL
      • www_browser.pl -- Open a URL in the users browser
      • prolog_pack.pl -- A package manager for Prolog
      • prolog_config.pl -- Provide configuration information
      • git.pl -- Run GIT commands
      • strings.pl -- String utilities
      • dif.pl -- The dif/2 constraint
      • dialect.pl -- Support multiple Prolog dialects
      • edinburgh.pl -- Some traditional Edinburgh predicates
      • ansi_term.pl -- Print decorated text to ANSI consoles
      • terms.pl -- Term manipulation
      • listing.pl -- List programs and pretty print clauses
      • persistency.pl -- Provide persistent dynamic predicates
      • pengines_sandbox.pl -- Declare Pengine interaction sandbox-safe
      • term_to_json.pl
      • prolog_stack.pl -- Examine the Prolog stack
      • prolog_clause.pl -- Get detailed source-information about a clause
      • prolog_breakpoints.pl -- Manage Prolog break-points
      • wfs.pl -- Well Founded Semantics interface
      • mallocinfo.pl -- Memory allocation details
      • chr.pl
      • sort.pl
      • dicts.pl -- Dict utilities
      • varnumbers.pl -- Utilities for numbered terms
      • nb_set.pl -- Non-backtrackable sets
      • check.pl -- Consistency checking
      • base32.pl -- Base32 encoding and decoding
      • charsio.pl -- I/O on Lists of Character Codes
      • codesio.pl -- I/O on Lists of Character Codes
      • coinduction.pl -- Co-Logic Programming
      • date.pl -- Process dates and times
      • heaps.pl -- heaps/priority queues
      • rbtrees.pl -- Red black trees
      • statistics.pl -- Get information about resource usage
      • when.pl -- Conditional coroutining
      • backcomp.pl -- Backward compatibility
      • odbc.pl
      • tables.pl -- XSB interface to tables
      • intercept.pl -- Intercept and signal interface
      • xmlenc.pl -- XML encryption library
      • rlimit.pl
      • paxos.pl -- A Replicated Data Store
      • cgi.pl -- Read CGI parameters
      • thread.pl -- High level thread primitives
      • yaml.pl -- Process YAML data
      • rdf_write.pl -- Write RDF/XML from a list of triples
      • sgml_write.pl -- XML/SGML writer module
      • redis.pl -- Redis client
      • utf8.pl -- UTF-8 encoding/decoding on lists of character codes.
      • editline.pl -- BSD libedit based command line editing
      • increval.pl -- Incremental dynamic predicate modification
      • explain.pl -- Describe Prolog Terms
      • archive.pl -- Access several archive formats
      • crypt.pl
      • threadutil.pl -- Interactive thread utilities
      • plunit.pl -- Unit Testing
      • redis_streams.pl -- Using Redis streams
      • doc_latex.pl -- PlDoc LaTeX backend
      • test_cover.pl -- Clause coverage analysis
      • prolog_trace.pl -- Print access to predicates
      • prolog_wrap.pl -- Wrapping predicates
        • wrap_predicate/4
        • unwrap_predicate/2
        • current_predicate_wrapper/4
      • quintus.pl -- Quintus compatibility
      • shell.pl -- Elementary shell commands
      • writef.pl -- Old-style formatted write
      • prolog_history.pl -- Per-directory persistent commandline history
      • readline.pl -- GNU readline interface
      • help.pl -- Text based manual
      • isub.pl -- isub: a string similarity measure
      • doc_files.pl -- Create stand-alone documentation files
      • double_metaphone.pl -- Phonetic string matching
      • oset.pl -- Ordered set manipulation
      • prolog_debug.pl -- User level debugging tools
      • rdf.pl -- RDF/XML parser
      • stomp.pl -- STOMP client.
      • prolog_profile.pl -- Execution profiler
      • prolog_codewalk.pl -- Prolog code walker
      • readln.pl -- Read line as list of tokens
      • mqi.pl
      • optparse.pl -- command line parsing
      • make.pl -- Reload modified source files
      • table.pl
      • system.pl -- System utilities
      • protobufs.pl -- Google's Protocol Buffers ("protobufs")
      • rewrite_term.pl
      • snowball.pl -- The Snowball multi-lingual stemmer library
      • streams.pl -- Manage Prolog streams
      • fastrw.pl -- Fast reading and writing of terms
      • unicode.pl -- Unicode string handling
      • rdf_triple.pl -- Create triples from intermediate representation
      • rdf_parser.pl
      • prolog_jiti.pl -- Just In Time Indexing (JITI) utilities
      • pwp.pl -- Prolog Well-formed Pages
      • zip.pl -- Access resource ZIP archives
      • prolog_stream.pl -- A stream with Prolog callbacks
      • streampool.pl -- Input multiplexing
      • macros.pl -- Macro expansion
      • udp_broadcast.pl -- A UDP broadcast proxy
      • xmldsig.pl -- XML Digital signature
      • prolog_metainference.pl -- Infer meta-predicate properties
      • xsdp_types.pl -- XML-Schema primitive types
      • rwlocks.pl -- Read/write locks
      • prolog_versions.pl -- Demand specific Prolog versions
      • edit.pl -- Editor interface
      • portray_text.pl -- Portray text
 wrap_predicate(:Head, +Name, -Wrapped, +Body) is det
Wrap the predicate referenced by Head using Body. Subsequent calls to Head call the given Body term. Body may call the original definition through Wrapped. Wrapped is a term of the shape below, where Closure is an opaque blob.
call(Closure(A1, ...))

Name names the wrapper for inspection using predicate_property/2 or deletion using unwrap_predicate/2. If Head has a wrapper with Name the Body of the existing wrapper is updated without changing the order of the registered wrappers. The same predicate may be wrapped multiple times. Multiple wrappers are executed starting with the last registered (outermost).

The predicate referenced by Head does not need to be defined at the moment the wrapper is installed. If Head is undefined, the predicate is created instead of searched for using e.g., the auto loader.

Registered wrappers are not part of saved states (see qsave_program/2) and thus need to be re-registered, for example using initialization/1.