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critcl::literals(n)        C Runtime In Tcl (CriTcl)       critcl::literals(n)

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NAME
       critcl::literals - CriTcl Utilities: Constant string pools

SYNOPSIS
       package require Tcl  8.4

       package require critcl  ?3.1.11?

       package require critcl::literals  ?1.1?

       ::critcl::literals::def name definition

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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::literals
       package. This package provides convenience commands for advanced
       functionality built on top of both critcl core and package
       critcl::iassoc.

       Many packages will have a fixed set of string constants occuring in one
       or places. Most of them will be coded to create a new string Tcl_Obj*
       from a C char* every time the constant is needed, as this is easy to
       to, despite the inherent waste of memory.

       This package was written to make declaration and management of string
       pools which do not waste memory as easy as the wasteful solution,
       hiding all attendant complexity from the user.

       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::literals::def name definition
              This command defines a C function with the given name which
              provides access to a pool of constant strings with a Tcl
              interpreter.

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

              The new function has two parameters, a Tcl_Interp* pointer
              refering to the interpreter holding the string pool, and a code
              of type "name_names" (see below), the symbolic name of the
              literal to return. Tcl result of the function is a Tcl_Obj*
              pointer to the requested string constant.

              The underlying string pool is automatically initialized on first
              access, and finalized on interpreter destruction.

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

              name   The function providing access to the string pool.  Its
                     signature is

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

              name_names
                     A C enumeration type containing the symbolic names of the
                     strings provided by the pool.

              name.h A header file containing the declarations for the
                     accessor function and enumeration type, 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   New in version 1.1: 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.

EXAMPLE
       The example shown below is the specification of the string pool pulled
       from the draft work on a Tcl binding to Linux's inotify APIs.

              package require Tcl 8.5
              package require critcl 3.1.11

              critcl::buildrequirement {
                  package require critcl::literals
              }

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

              # Declarations: tcl_inotify_strings.h
              # Type:         tcl_inotify_strings_names
              # Accessor:     Tcl_Obj* tcl_inotify_strings (Tcl_Interp*               interp,
              #                                             tcl_inotify_strings_names literal);
              # ResultType:   tcl_inotify_strings

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, dynamic code generation, dynamic compilation,
       generate package, linker, literal pool, on demand compilation, on-the-
       fly compilation, singleton, string pool

CATEGORY
       Glueing/Embedded C code

COPYRIGHT
       Copyright (c) 2011-2015 Andreas Kupries

doc                                   1.1                  critcl::literals(n)