focal (3) critcl_enum.3tcl.gz

Provided by: critcl_3.1.17+dfsg-1_all bug

NAME

       critcl::enum - CriTcl Utilities: String/Integer mapping

SYNOPSIS

       package require Tcl  8.4

       package require critcl  ?3.1.11?

       package require critcl::enum  ?1.0.1?

       ::critcl::enum::def name definition

________________________________________________________________________________________________________________

DESCRIPTION

       Welcome  to the C Runtime In Tcl, CriTcl for short, a system to build C extension packages for Tcl on the
       fly, from C code embedded within Tcl scripts, for all who wish to make their code go faster.

       This document is the reference manpage for the critcl::enum package. This  package  provides  convenience
       commands for advanced functionality built on top of both critcl core and package critcl::literals.

       It  is an extended form of string pool which not only converts integer values into Tcl-level strings, but
       also handles the reverse direction, converting from strings to the associated integer values.

       It essentially provides a bi-directional mapping between a C enumeration type and a set of  strings,  one
       per  enumeration  value.  Note that the C enumeration in question is created by the definition. It is not
       possible to use the symbols of an existing enumeration type.

       This package was written to make the declaration and management of such mappings easy. It uses  a  string
       pool for one of the directions, using its ability to return shared literals and conserve memory.

       Its intended audience are mainly developers wishing to write Tcl packages with embedded C code.

       This package resides in the Core Package Layer of CriTcl.

       +----------------+
       |Applications    |
       | critcl         |
       | critcl::app    |
       +----------------+

       *================*
       |Core Packages   |
       | critcl         |
       | critcl::util   |
       *================*

       +----------------+
       |Support Packages|
       | stubs::*       |
       | md5, platform  |
       |  ...           |
       +----------------+

API

       ::critcl::enum::def name definition
              This  command  defines  two C functions for the conversion between C values and Tcl_Obj'ects, with
              named derived from name.

              The definition dictionary provides the mapping from the specified C-level symbolic  names  to  the
              strings themselves.

              The package generates multiple things (declarations and definitions) with names derived from name,
              which has to be a proper C identifier.

              name_pool_names
                     The C enumeration type containing the specified symbolic names.

              name_ToObj
                     The function converting from integer value to Tcl string.  Its signature is

                     Tcl_Obj* name_ToObj (Tcl_Interp* interp, name_names literal);

              name_GetFromObj
                     The function converting from Tcl string to integer value.  Its signature is

                     int name_GetFromObj (Tcl_Interp* interp, Tcl_Obj* obj, int flags, int* literal);

                     The flags are like for Tcl_GetIndexFromObj.

              name.h A header file containing the declarations for the converter functions,  for  use  by  other
                     parts of the system, if necessary.

                     The generated file is stored in a place where it will not interfere with the overall system
                     outside of the package,  yet  also  be  available  for  easy  inclusion  by  package  files
                     (csources).

              name   At  the  level  of critcl itself the command registers a new result-type for critcl::cproc,
                     which takes an integer result from the function and converts it to the equivalent string in
                     the pool for the script.

              name   At  the level of critcl itself the command registers a new argument-type for critcl::cproc,
                     which takes a Tcl string and converts it to the equivalent  integer  for  delivery  to  the
                     function.

EXAMPLE

       The  example shown below is the specification for a set of actions, methods, and the like, a function may
       take as argument.

              package require Tcl 8.5
              package require critcl 3.1.11

              critcl::buildrequirement {
                  package require critcl::enum
              }

              critcl::enum::def action {
                  w_create"create"
                  w_directory"directory"
                  w_events"events"
                  w_file"file"
                  w_handler"handler"
                  w_remove"remove"
              }

              # Declarations: action.h
              # Type:         action_names
              # Accessor:     Tcl_Obj* action_ToObj (Tcl_Interp* interp, int literal);
              # Accessor:     int action_GetFromObj (Tcl_Interp* interp, Tcl_Obj* o, int flags, int* literal);
              # ResultType:   action
              # ArgType:      action

AUTHORS

       Andreas Kupries

BUGS, IDEAS, FEEDBACK

       This document, and the package it describes, will undoubtedly contain bugs and  other  problems.   Please
       report  such at https://github.com/andreas-kupries/critcl.  Please also report any ideas for enhancements
       you may have for either package and/or documentation.

KEYWORDS

       C code, Embedded C Code, Tcl Interp Association, code generator, compile  &  run,  compiler,  conversion,
       dynamic  code  generation,  dynamic compilation, generate package, int to string mapping, linker, literal
       pool, on demand compilation, on-the-fly compilation, singleton, string pool, string to int mapping

CATEGORY

       Glueing/Embedded C code

       Copyright (c) 2011-2015 Andreas Kupries