| /*
	|  * tclLink.c --
	|  *
	|  * This file implements linked variables (a C variable that is
Abstract|  * tied to a Tcl variable). The idea of linked variables was
	|  * first suggested by Andreas Stolcke and this implementation is
	|  * based heavily on a prototype implementation provided by
	|  * him.
	   *
	|  * Copyright (c) 1993 The Regents of the University of California.
	|  * All rights reserved.
	|  *
	|  * Permission is hereby granted, without written agreement and without
Copyright  * license or royalty fees, to use, copy, modify, and distribute this
	|  * software and its documentation for any purpose, provided that the
	|  * above copyright notice and the following two paragraphs appear in
	|  * all copies of this software.
	|  *
	|  * ...
	   */

Revision| static char rcsid[] = "$Header: /user6/ouster/tcl/RCS/tclLink.c,v 1.5 94/04/23
String	| 16:12:30 ouster Exp $ SPRITE (Berkeley)";

Includes| #include "tclInt.h"

	| /*
	|  * For each linked variable there is a data structure of the following
	|  * type, which describes the link and is the clientData for the trace
	|  * set on the Tcl variable.
	|  */
	|
	| typedef struct Link {
	|     Tcl_Interp *interp;	/* Interpreter containing Tcl variable. */
Decls.	|     char *addr;		/* Location of C variable. */
	|     int type;			/* Type of link (TCL_LINK_INT, etc.). */
	|     int writable;		/* Zero means Tcl variable is read-only. */
	|     union {
	|         int i;
	|         double d;
	|     } lastValue;		/* Last known value of C variable; used to
	|				 * avoid string conversions. */
	| } Link;

	| /*
	|  * Prototypes for procedures referenced only in this file:
	|  */
Proto-	|
types	| static char *			LinkTraceProc _ANSI_ARGS_((ClientData clientData,
	| 				    Tcl_Interp *interp, char *name1, char *name2,
	| 				    int flags));
	| static char *			StringValue _ANSI_ARGS_((Link *linkPtr,
	| 	  			    char *buffer));