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critcl::bitmap(n) C Runtime In Tcl (CriTcl) critcl::bitmap(n)
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NAME
critcl::bitmap - CriTcl Utilities: Bitset en- and decoding
SYNOPSIS
package require Tcl 8.4
package require critcl ?3.1.11?
package require critcl::bitmap ?1.0.1?
::critcl::bitmap::def name definition ?exclusions?
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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::bitmap package.
This package provides convenience commands for advanced functionality
built on top of both critcl core and package critcl::iassoc.
C level libraries often use bit-sets to encode many flags into a single
value. Tcl bindings to such libraries now have the task of converting a
Tcl representation of such flags (like a list of strings) into such
bit-sets, and back. Note here that the C-level information has to be
something which already exists. The package does not create these
values. This is in contrast to the package critcl::enum which creates
an enumeration based on the specified symbolic names.
This package was written to make the declaration and management of such
bit-sets and their associated conversions functions easy, 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::bitmap::def name definition ?exclusions?
This command defines two C functions for the conversion of the
named bit-set into Tcl lists, and vice versa. The underlying
mapping tables are automatically initialized on first access,
and finalized on interpreter destruction.
The definition dictionary provides the mapping from the Tcl-
level symbolic names of the flags to their C expressions (often
the name of the macro specifying the actual value). Note here
that the C-level information has to be something which already
exists. The package does not create these values. This is in
contrast to the package critcl::enum which creates an
enumeration based on the specified symbolic names.
The optional exlusion list is for the flags/bit-sets for which
conversion from bit-set to flag, i.e. decoding makes no sense.
One case for such, for example, are flags representing a
combination of other flags.
The package generates multiple things (declarations and
definitions) with names derived from name, which has to be a
proper C identifier.
name_encode
The function for encoding a Tcl list of strings into the
equivalent bit-set. Its signature is
int name_encode (Tcl_Interp* interp, Tcl_Obj* flags, int* result);
The return value of the function is a Tcl error code, i.e.
TCL_OK, TCL_ERROR, etc.
name_decode
The function for decoding a bit-set into the equivalent
Tcl list of strings. Its signature is
Tcl_Obj* name_decode (Tcl_Interp* interp, int flags);
name.h A header file containing the declarations for the two
conversion 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 The name of a critcl argument type encapsulating the
encoder function for use by critcl::cproc.
name The name of a critcl result type encapsulating the
decoder function for use by critcl::cproc.
EXAMPLE
The example shown below is the specification of the event flags 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::bitmap
}
critcl::bitmap::def tcl_inotify_events {
accessed IN_ACCESS
all IN_ALL_EVENTS
attribute IN_ATTRIB
closed IN_CLOSE
closed-nowrite IN_CLOSE_NOWRITE
closed-write IN_CLOSE_WRITE
created IN_CREATE
deleted IN_DELETE
deleted-self IN_DELETE_SELF
dir-only IN_ONLYDIR
dont-follow IN_DONT_FOLLOW
modified IN_MODIFY
move IN_MOVE
moved-from IN_MOVED_FROM
moved-self IN_MOVE_SELF
moved-to IN_MOVED_TO
oneshot IN_ONESHOT
open IN_OPEN
overflow IN_Q_OVERFLOW
unmount IN_UNMOUNT
} {
all closed move oneshot
}
# Declarations: tcl_inotify_events.h
# Encoder: int tcl_inotify_events_encode (Tcl_Interp* interp, Tcl_Obj* flags, int* result);
# Decoder: Tcl_Obj* tcl_inotify_events_decode (Tcl_Interp* interp, int flags);
# crit arg-type tcl_inotify_events
# crit res-type tcl_inotify_events
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, bitmask, bitset, code
generator, compile & run, compiler, dynamic code generation, dynamic
compilation, flags, generate package, linker, on demand compilation,
on-the-fly compilation, singleton
CATEGORY
Glueing/Embedded C code
COPYRIGHT
Copyright (c) 2011-2015 Andreas Kupries
doc 1.0.1 critcl::bitmap(n)