- swipl
- library
- error.pl
- debug.pl -- Print debug messages and test assertions
- apply.pl -- Apply predicates on a list
- lists.pl -- List Manipulation
- broadcast.pl -- Event service
- predicate_options.pl -- Access and analyse predicate options
- shlib.pl -- Utility library for loading foreign objects (DLLs, shared objects)
- option.pl -- Option list processing
- 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
- operators.pl -- Manage operators
- pairs.pl -- Operations on key-value lists
- prolog_source.pl -- Examine Prolog source-files
- quasi_quotations.pl -- Define Quasi Quotation syntax
- url.pl -- Analysing and constructing URL
- www_browser.pl -- Open a URL in the users browser
- prolog_colour.pl -- Prolog syntax colouring support.
- record.pl -- Access compound arguments by name
- prolog_xref.pl -- Prolog cross-referencer data collection
- occurs.pl -- Finding and counting sub-terms
- ordsets.pl -- Ordered set manipulation
- assoc.pl -- Binary associations
- ugraphs.pl -- Graph manipulation library
- iostream.pl -- Utilities to deal with streams
- atom.pl -- Operations on atoms
- prolog_pack.pl -- A package manager for Prolog
- solution_sequences.pl -- Modify solution sequences
- git.pl -- Run GIT commands
- ctypes.pl -- Character code classification
- utf8.pl -- UTF-8 encoding/decoding on lists of character codes.
- base64.pl -- Base64 encoding and decoding
- persistency.pl -- Provide persistent dynamic predicates
- pure_input.pl -- Pure Input from files and streams
- nb_set.pl -- Non-backtrackable sets
- aggregate.pl -- Aggregation operators on backtrackable predicates
- csv.pl -- Process CSV (Comma-Separated Values) data
- dialect.pl -- Support multiple Prolog dialects
- apply_macros.pl -- Goal expansion rules to avoid meta-calling
- yall.pl -- Lambda expressions
- prolog_code.pl -- Utilities for reasoning about code
- dif.pl -- The dif/2 constraint
- thread.pl -- High level thread primitives
- rbtrees.pl -- Red black trees
- nb_rbtrees.pl -- Non-backtrackable operations on red black trees
- random.pl -- Random numbers
- sandbox.pl -- Sandboxed Prolog code
- prolog_format.pl -- Analyse format specifications
- pprint.pl -- Pretty Print Prolog terms
- modules.pl -- Module utility predicates
- lazy_lists.pl -- Lazy list handling
- edinburgh.pl -- Some traditional Edinburgh predicates
- prolog_clause.pl -- Get detailed source-information about a clause
- prolog_breakpoints.pl -- Manage Prolog break-points
- dicts.pl -- Dict utilities
- macros.pl -- Macro expansion
- terms.pl -- Term manipulation
- statistics.pl -- Get information about resource usage
- backcomp.pl -- Backward compatibility
- charsio.pl -- I/O on Lists of Character Codes
- hashtable.pl -- Hash tables
- portray_text.pl -- Portray text
- date.pl -- Process dates and times
- writef.pl -- Old-style formatted write
- prolog_codewalk.pl -- Prolog code walker
- listing.pl -- List programs and pretty print clauses
- prolog_metainference.pl -- Infer meta-predicate properties
- prolog_profile.pl -- Execution profiler
- prolog_coverage.pl -- Coverage analysis tool
- prolog_autoload.pl -- Autoload all dependencies
- check.pl -- Consistency checking
- varnumbers.pl -- Utilities for numbered terms
- system.pl -- System utilities
- quintus.pl -- Quintus compatibility
- shell.pl -- Elementary shell commands
- rwlocks.pl -- Read/write locks
- oset.pl -- Ordered set manipulation
- prolog_stack.pl -- Examine the Prolog stack
- prolog_debug.pl -- User level debugging tools
- optparse.pl -- command line parsing
- threadutil.pl -- Interactive thread utilities
- prolog_history.pl -- Per-directory persistent commandline history
- prolog_config.pl -- Provide configuration information
- make.pl -- Reload modified source files
- ansi_term.pl -- Print decorated text to ANSI consoles
- prolog_versions.pl -- Demand specific (Prolog) versions
- base32.pl -- Base32 encoding and decoding
- strings.pl -- String utilities
- edit.pl -- Editor interface
- heaps.pl -- heaps/priority queues
- win_menu.pl -- Console window menu
- tty.pl -- Terminal operations
- prolog_wrap.pl -- Wrapping predicates
- sort.pl
- wfs.pl -- Well Founded Semantics interface
- zip.pl -- Access resource ZIP archives
- coinduction.pl -- Co-Logic Programming
- streams.pl -- Manage Prolog streams
- help.pl -- Text based manual
- codesio.pl -- I/O on Lists of Character Codes
- when.pl -- Conditional coroutining
- prolog_trace.pl -- Print access to predicates
- exceptions.pl -- Exception classification
- increval.pl -- Incremental dynamic predicate modification
- tables.pl -- XSB interface to tables
- fastrw.pl -- Fast reading and writing of terms
- intercept.pl -- Intercept and signal interface
- qsave.pl -- Save current program as a state or executable
- files.pl
- explain.pl -- Describe Prolog Terms
- prolog_jiti.pl -- Just In Time Indexing (JITI) utilities
- library
- trace(:Pred) is det
- trace(:Pred, +PortSpec) is det
- Print passes through ports of specified predicates. Pred is a,
possible partial, specification of a predicate as it is also used be
spy/1 and similar predicates. Where a full predicate specification
is of the shape
Module:Name/Arity
(or `//Arity for non-terminals), both the module and arity may be omitted in which case Pred refers to all matching predicates. PortSpec is either a single port (call
,exit
,fail
orredo
), preceded with+
or-
or a list of these. The predicate modifies the current trace specification and then installs a suitable wrapper for the predicate using wrap_predicate/4. For example:?- trace(append). % lists:append/2: [all] % lists:append/3: [all] % append/1: [all] true. ?- append([a,b], [c], L). T [10] Call: lists:append([a, b], [c], _18032) T [19] Call: lists:append([b], [c], _19410) T [28] Call: lists:append([], [c], _20400) T [28 +0.1ms] Exit: lists:append([], [c], [c]) T [19 +0.2ms] Exit: lists:append([b], [c], [b, c]) T [10 +0.5ms] Exit: lists:append([a, b], [c], [a, b, c]) L = [a, b, c]. ?- trace(append, -all). % lists:append/2: Not tracing % lists:append/3: Not tracing % append/1: Not tracing
The text between [] indicates the call depth (first number) and for all ports except the
call
port the wall time since the start (call port) in milliseconds. Note that the instrumentation and print time is included in the time. In the example above the actual time is about 0.00001ms on todays hardware.In addition, conditions may be specified. In this case the the specification takes the shape
trace(:Head, Port(Condition))
. For example:?- trace(current_prolog_flag(Flag, Value), call(var(Flag))). ?- list_tracing. % Trace points (see trace/1,2) on: % system:current_prolog_flag(A,_): [call(var(A))]
This specification will only print the goal if the registered condition succeeds. Note that we can use the condition for its side effect and then fail to avoid printing the event. Clearing the trace event on all relevant ports removes the condition. There is currently no way to modify the condition without clearing the trace point first.