/usr/local/lib/swipl/library/tty.pl
All Application Manual Name SummaryHelp

  • swipl
    • library
      • error.pl
      • debug.pl
      • apply.pl
      • lists.pl
      • broadcast.pl -- Event service
      • predicate_options.pl
      • shlib.pl
      • option.pl
      • thread_pool.pl
      • gensym.pl
      • settings.pl -- Setting management
      • arithmetic.pl
      • 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
      • record.pl -- Access compound arguments by name
      • quasi_quotations.pl -- Define Quasi Quotation syntax
      • pure_input.pl -- Pure Input from files and streams
      • solution_sequences.pl -- Modify solution sequences
      • ordsets.pl -- Ordered set manipulation
      • random.pl -- Random numbers
      • base64.pl -- Base64 encoding and decoding
      • aggregate.pl -- Aggregation operators on backtrackable predicates
      • yall.pl -- Lambda expressions
      • 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
      • csv.pl -- Process CSV (Comma-Separated Values) data
      • pprint.pl -- Pretty Print Prolog terms
      • atom.pl -- Operations on atoms
      • 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
      • ugraphs.pl -- Graph manipulation library
      • iostream.pl -- Utilities to deal with streams
      • url.pl -- Analysing and constructing URL
      • www_browser.pl -- Open a URL in the users browser
      • prolog_pack.pl -- A package manager for Prolog
      • git.pl -- Run GIT commands
      • utf8.pl -- UTF-8 encoding/decoding on lists of character codes.
      • dialect.pl -- Support multiple Prolog dialects
      • system.pl -- System utilities
      • terms.pl -- Term manipulation
      • date.pl -- Process dates and times
      • persistency.pl -- Provide persistent dynamic predicates
      • prolog_stack.pl -- Examine the Prolog stack
      • edinburgh.pl -- Some traditional Edinburgh predicates
      • prolog_clause.pl -- Get detailed source-information about a clause
      • prolog_breakpoints.pl -- Manage Prolog break-points
      • wfs.pl -- Well Founded Semantics interface
      • prolog_code.pl -- Utilities for reasoning about code
      • sort.pl
      • dicts.pl -- Dict utilities
      • dif.pl -- The dif/2 constraint
      • varnumbers.pl -- Utilities for numbered terms
      • pio.pl -- Pure I/O
      • 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
      • 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
      • prolog_profile.pl -- Execution profiler
      • optparse.pl -- command line parsing
      • ctypes.pl -- Character code classification
      • listing.pl -- List programs and pretty print clauses
      • nb_set.pl -- Non-backtrackable sets
      • fastrw.pl -- Fast reading and writing of terms
      • prolog_codewalk.pl -- Prolog code walker
      • prolog_metainference.pl -- Infer meta-predicate properties
      • strings.pl -- String utilities
      • shell.pl -- Elementary shell commands
      • quintus.pl -- Quintus compatibility
      • make.pl -- Reload modified source files
      • tables.pl -- XSB interface to tables
      • tty.pl -- Terminal operations
        • tty_clear/0
        • tty_flash/0
        • menu/3
 menu(+Title, +Options, -Choice) is semidet
Show a menu. The display is cleared, the title is centered at the top, the options are displayed and finally the user actions are parsed and the user's choice is returned. The screen looks like this:
        --------------------------------------------
        |                                          |
        |                  Title                   |
        |                                          |
        |   1) Option One                          |
        |   2) Option Two                          |
        |   3) Quit                                |
        |                                          |
        |   Your Choice? *                         |
        |                                          |

The user selects an item by pressing the number of the item, or the first letter of the option. If more then one option match, the common prefix of the matching options is given and the user is expected to type the next character. On illegal input the screen is flashed (or a beep is given if the terminal can't flash the screen).

Text fields (the title and option texts) are either plain atoms or terms Fmt/Args. In the latter case the argument is transformed into an atom using format/3.

The specification of an option is a term PrologName:UserName. PrologName is an atom, which is returned as choice if the user selects this menu item. UserName is processed as a text field (see above) and displayed. The entries are numbered automatically.

The example above could be defined as:

get_action(Choice) :-
        menu('Title',
                [ option_1 : 'Option One'
                , option_2 : 'Option Two'
                , quit     : 'Quit'
                ], Choice).