- 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(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(terms): Term manipulation
- 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
- Packages
- Reference manual
A.2 library(ansi_term): Print decorated text to ANSI consoles
This library allows for exploiting the color and attribute facilities of most modern terminals using ANSI escape sequences. This library provides the following:
- ansi_format/3 allows writing messages to the terminal with ansi attributes.
- It defines the hook prolog:message_line_element/2, which provides ansi attributes for print_message/2.
- [det]ansi_format(+ClassOrAttributes, +Format, +Args)
- Format text with ANSI attributes. This predicate behaves as
format/2 using Format
and Args, but if the
current_outputis a terminal, it adds ANSI escape sequences according to Attributes. For example, to print a text in bold cyan, do?- ansi_format([bold,fg(cyan)], 'Hello ~w', [world]).
Attributes is either a single attribute, a list thereof or a term that is mapped to concrete attributes based on the current theme (see prolog:console_color/2). The attribute names are derived from the ANSI specification. See the source for sgr_code/2 for details. Some commonly used attributes are:
- bold
- underline
fg(Color),bg(Color),hfg(Color),hbg(Color)- For
fg(Color)andbg(Color), the colour name can be’#RGB' or’#RRGGBB' fg8(Spec),bg8(Spec)- 8-bit color specification. Spec is a colour name,
h(Color)or an integer 0..255. fg(R, G, B),bg(R, G, B)- 24-bit (direct color) specification. The components are integers in the range 0..255.
Defined color constants are below.
defaultcan be used to access the default color of the terminal.- black, red, green, yellow, blue, magenta, cyan, white
ANSI sequences are sent if and only if
- The
current_outputhas the propertytty(true)(see stream_property/2). - The Prolog flag
color_termistrue.
- [semidet,multifile]prolog:console_color(+Term, -AnsiAttributes)
- Hook that allows for mapping abstract terms to concrete ANSI attributes.
This hook is used by theme files to adjust the rendering based on
user preferences and context. Defaults are defined in the file
boot/messages.pl.- See also
library(theme/dark)for an example implementation and the Term values used by the system messages.
- [semidet,multifile]prolog:message_line_element(+Stream, +Term)
- Hook implementation that deals with
ansi(+Attr, +Fmt, +Args)in message specifications. - [semidet]ansi_get_color(+Which, -RGB)
- Obtain the RGB color for an ANSI color parameter. Which
is either a color alias or an integer ANSI color id. Defined aliases are
foregroundandbackground. This predicate sends a request to the console (user_output) and reads the reply. This assumes anxtermcompatible terminal.RGB is a term rgb(Red,Green,Blue). The color components are integers in the range 0..65535.