- 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(gensym): Generate unique identifiers
- 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(main): Provide entry point for scripts
- library(nb_set): Non-backtrackable set
- library(www_browser): Activating your Web-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(predicate_options): Declare option-processing of predicates
- library(prolog_jiti): Just In Time Indexing (JITI) utilities
- library(prolog_pack): A package manager for Prolog
- library(prolog_xref): Prolog cross-referencer data collection
- library(quasi_quotations): Define Quasi Quotation syntax
- library(random): Random numbers
- library(readutil): Read utilities
- library(record): Access named fields in a term
- library(registry): Manipulating the Windows registry
- library(settings): Setting management
- library(strings): String utilities
- library(simplex): Solve linear programming problems
- library(solution_sequences): Modify solution sequences
- library(tables): XSB interface to tables
- library(thread): High level thread primitives
- library(thread_pool): Resource bounded thread management
- library(ugraphs): Unweighted Graphs
- library(url): Analysing and constructing URL
- library(varnumbers): Utilities for numbered terms
- library(yall): Lambda expressions
- The SWI-Prolog library
- Reference manual
- Jan Wielemaker
- See also
library(config)distributed with XPCE provides an alternative aimed at graphical applications.
This library allows management of configuration settings for Prolog applications. Applications define settings in one or multiple files using the directive setting/4 as illustrated below:
:- use_module(library(settings)). :- setting(version, atom, '1.0', 'Current version'). :- setting(timeout, number, 20, 'Timeout in seconds').
Settings are local to a module. This implies they are defined in a two-level namespace. Managing settings per module greatly simplifies assembling large applications from multiple modules that configuration through settings. This settings management library ensures proper access, loading and saving of settings.
- [det]setting(:Name, +Type, +Default, +Comment)
- Define a setting. Name denotes the name of the setting, Type
its type. Default is the value before it is modified. Default
can refer to environment variables and can use arithmetic expressions as
defined by eval_default/4.
If a second declaration for a setting is encountered, it is ignored if Type and Default are the same. Otherwise a permission_error is raised.
Name Name of the setting (an atom) Type Type for setting. One of
anyor a type defined by must_be/2.
Default Default value for the setting. Comment Atom containing a (short) descriptive note.
- [nondet]setting(:Name, ?Value)
- True when Name is a currently defined setting with Value.
setting(Name, Value)only enumerates the settings of the current module. All settings can be enumerated using
setting(Module:Name, Value). This predicate is
detif Name is ground.
- [det]set_setting(:Name, +Value)
- Change a setting. Performs existence and type-checking for the setting.
If the effective value of the setting is changed it broadcasts the event
settings(changed(Module:Name, Old, New))
Note that modified settings are not automatically persistent. The application should call save_settings/0 to persist the changes.
- Restore the value of setting Name to its default. Broadcast a change like set_setting/2 if the current value is not the default.
- [det]set_setting_default(:Name, +Default)
- Change the default for a setting. The effect is the same as set_setting/2, but the new value is considered the default when saving and restoring a setting. It is intended to change application defaults in a particular context.
- [det]load_settings(File, +Options)
- Load local settings from File. Succeeds if File
does not exist, setting the default save-file to File. Options
- Define how to handle settings that are not defined. When
error, an error is printed and the setting is ignored. when
load, the setting is loaded anyway, waiting for a definition.
If possibly changed settings need to be persistent, the application must call save_settings/0 as part of its shutdown. In simple cases calling
- Save modified settings to File. Fails silently if the
settings file cannot be written. The save_settings/0
only attempts to save the settings file if some setting was modified
context_error(settings, no_default_file)for save_settings/0 if no default location is known.
- True if Setting is a currently defined setting
- [det]setting_property(+Setting, +Property)
- [nondet]setting_property(?Setting, ?Property)
- Query currently defined settings. Property is one of
- Type of the setting.
- Default value. If this is an expression, it is evaluated.
- Location where the setting is defined.
- List settings to
current_output. The second form only lists settings on the matching module.
- To be done
- Compute the required column widths
- convert_setting_text(+Type, +Text, -Value)
- Converts from textual form to Prolog Value. Used to convert
values obtained from the environment. Public to provide support in
user-interfaces to this library.