The help module provides support to create both on-line and off-line documentation on Prolog programs. Documentation must be defined by the hook predicate help_info/4. Documentation on a per module basis is provided if a help_info(module,Module,TitleString,DescriptionString) definition is given for Module. In that case the system also checks for Module:help_info/4 definitions.
The module supports production of the help information on standard output, (which can be converted into html format), and there also is an interface to a graphical user interface based on library(tcltk).
This section lists the hook predicates which an application can define for the help module.
Provides help information for Class and Key (both must be atoms). Usage and Expl are Prolog strings. Typically the Usage string is a short summary, and Expl is a longer explanation. Class is typically pred, hook, flag, command, option, etc. Note that each module can have its own help_info predicates. You can also define user:help_info/4 declarations on the special class module. In that case, if a full documentation on a module is requested the Usage string is used as the title and the Expl string as an introduction to the module. There can also be Module:help_info/4 declarations on the special class `class'. If a full listing on a class in Module is requested, then Usage and Expl are used as the title and introduction to that section.
This section lists the predicates defined by the help module.
Lists all help information.
Use help/0 to see for which modules help is available. Use help/1 for an overview which classes are available for a given module. Use help(Module,Class) to see for which keys help is available.
Use help_module(M) for a full listing of the help information available on module M. Without M uses module user.
Use help_class(C,M) for a full listing of the help information available for class C in module M. Without M module user is assumed.
Use help_key(K,C,M) for a full listing of the help information available for key K in class C in module M. If C (and M) are not given, then use variable for C (and M).
Interface of the help system and a graphical user interface based on library(tcltk). Menu must be a menu already existing for Tcl/Tk interpreter Interp. The various help messages are added as cascaded menu entries in Menu. Cf. also the help/1 predicate and the help_info/4 hook predicate.