Provided by: critcl_3.1.18.1+dfsg-3_amd64 
NAME
critcl::enum - CriTcl Utilities: String/Integer mapping
SYNOPSIS
package require Tcl 8.4
package require critcl ?3.1.11?
package require critcl::enum ?1.1?
::critcl::enum::def name definition ?mode?
_________________________________________________________________________________________________
DESCRIPTION
C Runtime In Tcl, or CriTcl , is a system for compiling C code embedded in Tcl on the fly
and either loading the resulting objects into Tcl for immediate use or packaging them for
distribution. Use CriTcl to improve performance by rewriting in C those routines that are
performance bottlenecks.
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 ?mode?
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 mode-list configures the output somewhat. The two allowed modes are +list and
tcl. All modes can be used together. The default mode is tcl. Using mode +list
implies tcl as well.
For mode tcl the new function has two arguments, a Tcl_Interp* pointer refering to
the interpreter holding the string pool, and a code of type "name_pool_names" (see
below), the symbolic name of the string to return. The result of the function is a
Tcl_Obj* pointer to the requested string constant.
For mode +list all of tcl applies, plus an additional function is generated which
takes three arguments, in order: a Tcl_Interp* pointer refering to the interpreter
holding the string pool, an int holding the size of the last argument, and an array
of type "name_pool_names" holding the codes (see below), the symbolic names of the
strings to return. The result of the function is a Tcl_Obj* pointer to a Tcl list
holding the requested string constants.
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_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_ToObjList
The mode +list function converting from integer array to Tcl list of
strings. Its signature is
Tcl_Obj* name_ToObjList (Tcl_Interp* interp, int c, 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
Copyright (c) 2011-2018 Andreas Kupries