shared_source/c_tcl_base_7_5_w_mods/tclresolve.c

/* $Header$ */

/*
 * tclResolve.c --
 *
 *      Contains hooks for customized command/variable name resolution
 *      schemes.  These hooks allow extensions like [incr Tcl] to add
 *      their own name resolution rules to the Tcl language.  Rules can
 *      be applied to a particular namespace, to the interpreter as a
 *      whole, or both.
 *
 * Copyright (c) 1998 Lucent Technologies, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclresolve.c,v 1.1.1.1 2001/06/13 04:45:45 dtashley Exp $
 */

#include "tclInt.h"

/*
 * Declarations for procedures local to this file:
 */

static void             BumpCmdRefEpochs _ANSI_ARGS_((Namespace *nsPtr));


/*
 *----------------------------------------------------------------------
 *
 * Tcl_AddInterpResolvers --
 *
 *      Adds a set of command/variable resolution procedures to an
 *      interpreter.  These procedures are consulted when commands
 *      are resolved in Tcl_FindCommand, and when variables are
 *      resolved in TclLookupVar and LookupCompiledLocal.  Each
 *      namespace may also have its own set of resolution procedures
 *      which take precedence over those for the interpreter.
 *
 *      When a name is resolved, it is handled as follows.  First,
 *      the name is passed to the resolution procedures for the
 *      namespace.  If not resolved, the name is passed to each of
 *      the resolution procedures added to the interpreter.  Finally,
 *      if still not resolved, the name is handled using the default
 *      Tcl rules for name resolution.
 *
 * Results:
 *      Returns pointers to the current name resolution procedures
 *      in the cmdProcPtr, varProcPtr and compiledVarProcPtr
 *      arguments.
 *
 * Side effects:
 *      If a compiledVarProc is specified, this procedure bumps the
 *      compileEpoch for the interpreter, forcing all code to be
 *      recompiled.  If a cmdProc is specified, this procedure bumps
 *      the cmdRefEpoch in all namespaces, forcing commands to be
 *      resolved again using the new rules.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_AddInterpResolvers(interp, name, cmdProc, varProc, compiledVarProc)

    Tcl_Interp *interp;                 /* Interpreter whose name resolution
                                         * rules are being modified. */
    char *name;                         /* Name of this resolution scheme. */
    Tcl_ResolveCmdProc *cmdProc;        /* New procedure for command
                                         * resolution */
    Tcl_ResolveVarProc *varProc;        /* Procedure for variable resolution
                                         * at runtime */
    Tcl_ResolveCompiledVarProc *compiledVarProc;
                                        /* Procedure for variable resolution
                                         * at compile time. */
{
    Interp *iPtr = (Interp*)interp;
    ResolverScheme *resPtr;

    /*
     *  Since we're adding a new name resolution scheme, we must force
     *  all code to be recompiled to use the new scheme.  If there
     *  are new compiled variable resolution rules, bump the compiler
     *  epoch to invalidate compiled code.  If there are new command
     *  resolution rules, bump the cmdRefEpoch in all namespaces.
     */
    if (compiledVarProc) {
        iPtr->compileEpoch++;
    }
    if (cmdProc) {
        BumpCmdRefEpochs(iPtr->globalNsPtr);
    }

    /*
     *  Look for an existing scheme with the given name.  If found,
     *  then replace its rules.
     */
    for (resPtr = iPtr->resolverPtr; resPtr != NULL; resPtr = resPtr->nextPtr) {
        if (*name == *resPtr->name && strcmp(name, resPtr->name) == 0) {
            resPtr->cmdResProc = cmdProc;
            resPtr->varResProc = varProc;
            resPtr->compiledVarResProc = compiledVarProc;
            return;
        }
    }

    /*
     *  Otherwise, this is a new scheme.  Add it to the FRONT
     *  of the linked list, so that it overrides existing schemes.
     */
    resPtr = (ResolverScheme *) ckalloc(sizeof(ResolverScheme));
    resPtr->name = (char*)ckalloc((unsigned)(strlen(name)+1));
    strcpy(resPtr->name, name);
    resPtr->cmdResProc = cmdProc;
    resPtr->varResProc = varProc;
    resPtr->compiledVarResProc = compiledVarProc;
    resPtr->nextPtr = iPtr->resolverPtr;
    iPtr->resolverPtr = resPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetInterpResolvers --
 *
 *      Looks for a set of command/variable resolution procedures with
 *      the given name in an interpreter.  These procedures are
 *      registered by calling Tcl_AddInterpResolvers.
 *
 * Results:
 *      If the name is recognized, this procedure returns non-zero,
 *      along with pointers to the name resolution procedures in
 *      the Tcl_ResolverInfo structure.  If the name is not recognized,
 *      this procedure returns zero.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetInterpResolvers(interp, name, resInfoPtr)

    Tcl_Interp *interp;                 /* Interpreter whose name resolution
                                         * rules are being queried. */
    char *name;                         /* Look for a scheme with this name. */
    Tcl_ResolverInfo *resInfoPtr;       /* Returns pointers to the procedures,
                                         * if found */
{
    Interp *iPtr = (Interp*)interp;
    ResolverScheme *resPtr;

    /*
     *  Look for an existing scheme with the given name.  If found,
     *  then return pointers to its procedures.
     */
    for (resPtr = iPtr->resolverPtr; resPtr != NULL; resPtr = resPtr->nextPtr) {
        if (*name == *resPtr->name && strcmp(name, resPtr->name) == 0) {
            resInfoPtr->cmdResProc = resPtr->cmdResProc;
            resInfoPtr->varResProc = resPtr->varResProc;
            resInfoPtr->compiledVarResProc = resPtr->compiledVarResProc;
            return 1;
        }
    }

    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_RemoveInterpResolvers --
 *
 *      Removes a set of command/variable resolution procedures
 *      previously added by Tcl_AddInterpResolvers.  The next time
 *      a command/variable name is resolved, these procedures
 *      won't be consulted.
 *
 * Results:
 *      Returns non-zero if the name was recognized and the
 *      resolution scheme was deleted.  Returns zero otherwise.
 *
 * Side effects:
 *      If a scheme with a compiledVarProc was deleted, this procedure
 *      bumps the compileEpoch for the interpreter, forcing all code
 *      to be recompiled.  If a scheme with a cmdProc was deleted,
 *      this procedure bumps the cmdRefEpoch in all namespaces,
 *      forcing commands to be resolved again using the new rules.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_RemoveInterpResolvers(interp, name)

    Tcl_Interp *interp;                 /* Interpreter whose name resolution
                                         * rules are being modified. */
    char *name;                         /* Name of the scheme to be removed. */
{
    Interp *iPtr = (Interp*)interp;
    ResolverScheme **prevPtrPtr, *resPtr;

    /*
     *  Look for an existing scheme with the given name.
     */
    prevPtrPtr = &iPtr->resolverPtr;
    for (resPtr = iPtr->resolverPtr; resPtr != NULL; resPtr = resPtr->nextPtr) {
        if (*name == *resPtr->name && strcmp(name, resPtr->name) == 0) {
            break;
        }
        prevPtrPtr = &resPtr->nextPtr;
    }

    /*
     *  If we found the scheme, delete it.
     */
    if (resPtr) {
        /*
         *  If we're deleting a scheme with compiled variable resolution
         *  rules, bump the compiler epoch to invalidate compiled code.
         *  If we're deleting a scheme with command resolution rules,
         *  bump the cmdRefEpoch in all namespaces.
         */
        if (resPtr->compiledVarResProc) {
            iPtr->compileEpoch++;
        }
        if (resPtr->cmdResProc) {
            BumpCmdRefEpochs(iPtr->globalNsPtr);
        }

        *prevPtrPtr = resPtr->nextPtr;
        ckfree(resPtr->name);
        ckfree((char *) resPtr);

        return 1;
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * BumpCmdRefEpochs --
 *
 *      This procedure is used to bump the cmdRefEpoch counters in
 *      the specified namespace and all of its child namespaces.
 *      It is used whenever name resolution schemes are added/removed
 *      from an interpreter, to invalidate all command references.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      Bumps the cmdRefEpoch in the specified namespace and its
 *      children, recursively.
 *
 *----------------------------------------------------------------------
 */

static void
BumpCmdRefEpochs(nsPtr)
    Namespace *nsPtr;                   /* Namespace being modified. */
{
    Tcl_HashEntry *entry;
    Tcl_HashSearch search;
    Namespace *childNsPtr;

    nsPtr->cmdRefEpoch++;

    for (entry = Tcl_FirstHashEntry(&nsPtr->childTable, &search);
            entry != NULL;
            entry = Tcl_NextHashEntry(&search)) {

        childNsPtr = (Namespace *) Tcl_GetHashValue(entry);
        BumpCmdRefEpochs(childNsPtr);
    }
}


/*
 *----------------------------------------------------------------------
 *
 * Tcl_SetNamespaceResolvers --
 *
 *      Sets the command/variable resolution procedures for a namespace,
 *      thereby changing the way that command/variable names are
 *      interpreted.  This allows extension writers to support different
 *      name resolution schemes, such as those for object-oriented
 *      packages.
 *
 *      Command resolution is handled by a procedure of the following
 *      type:
 *
 *        typedef int (Tcl_ResolveCmdProc) _ANSI_ARGS_((
 *              Tcl_Interp* interp, char* name, Tcl_Namespace *context,
 *              int flags, Tcl_Command *rPtr));
 *          
 *      Whenever a command is executed or Tcl_FindCommand is invoked
 *      within the namespace, this procedure is called to resolve the
 *      command name.  If this procedure is able to resolve the name,
 *      it should return the status code TCL_OK, along with the
 *      corresponding Tcl_Command in the rPtr argument.  Otherwise,
 *      the procedure can return TCL_CONTINUE, and the command will
 *      be treated under the usual name resolution rules.  Or, it can
 *      return TCL_ERROR, and the command will be considered invalid.
 *
 *      Variable resolution is handled by two procedures.  The first
 *      is called whenever a variable needs to be resolved at compile
 *      time:
 *
 *        typedef int (Tcl_ResolveCompiledVarProc) _ANSI_ARGS_((
 *              Tcl_Interp* interp, char* name, Tcl_Namespace *context,
 *              Tcl_ResolvedVarInfo *rPtr));
 *
 *      If this procedure is able to resolve the name, it should return
 *      the status code TCL_OK, along with variable resolution info in
 *      the rPtr argument; this info will be used to set up compiled
 *      locals in the call frame at runtime.  The procedure may also
 *      return TCL_CONTINUE, and the variable will be treated under
 *      the usual name resolution rules.  Or, it can return TCL_ERROR,
 *      and the variable will be considered invalid.
 *
 *      Another procedure is used whenever a variable needs to be
 *      resolved at runtime but it is not recognized as a compiled local.
 *      (For example, the variable may be requested via
 *      Tcl_FindNamespaceVar.) This procedure has the following type:
 *
 *        typedef int (Tcl_ResolveVarProc) _ANSI_ARGS_((
 *              Tcl_Interp* interp, char* name, Tcl_Namespace *context,
 *              int flags, Tcl_Var *rPtr));
 *
 *      This procedure is quite similar to the compile-time version.
 *      It returns the same status codes, but if variable resolution
 *      succeeds, this procedure returns a Tcl_Var directly via the
 *      rPtr argument.
 *
 * Results:
 *      Nothing.
 *
 * Side effects:
 *      Bumps the command epoch counter for the namespace, invalidating
 *      all command references in that namespace.  Also bumps the
 *      resolver epoch counter for the namespace, forcing all code
 *      in the namespace to be recompiled.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_SetNamespaceResolvers(namespacePtr, cmdProc, varProc, compiledVarProc)
    Tcl_Namespace *namespacePtr;        /* Namespace whose resolution rules
                                         * are being modified. */
    Tcl_ResolveCmdProc *cmdProc;        /* Procedure for command resolution */
    Tcl_ResolveVarProc *varProc;        /* Procedure for variable resolution
                                         * at runtime */
    Tcl_ResolveCompiledVarProc *compiledVarProc;
                                        /* Procedure for variable resolution
                                         * at compile time. */
{
    Namespace *nsPtr = (Namespace*)namespacePtr;

    /*
     *  Plug in the new command resolver, and bump the epoch counters
     *  so that all code will have to be recompiled and all commands
     *  will have to be resolved again using the new policy.
     */
    nsPtr->cmdResProc = cmdProc;
    nsPtr->varResProc = varProc;
    nsPtr->compiledVarResProc = compiledVarProc;

    nsPtr->cmdRefEpoch++;
    nsPtr->resolverEpoch++;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_GetNamespaceResolvers --
 *
 *      Returns the current command/variable resolution procedures
 *      for a namespace.  By default, these procedures are NULL.
 *      New procedures can be installed by calling
 *      Tcl_SetNamespaceResolvers, to provide new name resolution
 *      rules.
 *
 * Results:
 *      Returns non-zero if any name resolution procedures have been
 *      assigned to this namespace; also returns pointers to the
 *      procedures in the Tcl_ResolverInfo structure.  Returns zero
 *      otherwise.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_GetNamespaceResolvers(namespacePtr, resInfoPtr)

    Tcl_Namespace *namespacePtr;        /* Namespace whose resolution rules
                                         * are being modified. */
    Tcl_ResolverInfo *resInfoPtr;       /* Returns: pointers for all
                                         * name resolution procedures
                                         * assigned to this namespace. */
{
    Namespace *nsPtr = (Namespace*)namespacePtr;

    resInfoPtr->cmdResProc = nsPtr->cmdResProc;
    resInfoPtr->varResProc = nsPtr->varResProc;
    resInfoPtr->compiledVarResProc = nsPtr->compiledVarResProc;

    if (nsPtr->cmdResProc != NULL ||
        nsPtr->varResProc != NULL ||
        nsPtr->compiledVarResProc != NULL) {
        return 1;
    }
    return 0;
}


/* $History: tclresolve.c $
 * 
 * *****************  Version 1  *****************
 * User: Dtashley     Date: 1/02/01    Time: 1:04a
 * Created in $/IjuScripter, IjuConsole/Source/Tcl Base
 * Initial check-in.
 */ 

/* End of TCLRESOLVE.C */
1	/* $Header$ */
2
3	/*
4	* tclResolve.c --
5	*
6	* Contains hooks for customized command/variable name resolution
7	* schemes. These hooks allow extensions like [incr Tcl] to add
8	* their own name resolution rules to the Tcl language. Rules can
9	* be applied to a particular namespace, to the interpreter as a
10	* whole, or both.
11	*
12	* Copyright (c) 1998 Lucent Technologies, Inc.
13	*
14	* See the file "license.terms" for information on usage and redistribution
15	* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
16	*
17	* RCS: @(#) $Id: tclresolve.c,v 1.1.1.1 2001/06/13 04:45:45 dtashley Exp $
18	*/
19
20	#include "tclInt.h"
21
22	/*
23	* Declarations for procedures local to this file:
24	*/
25
26	static void BumpCmdRefEpochs _ANSI_ARGS_((Namespace *nsPtr));
27
28
29	/*
30	*----------------------------------------------------------------------
31	*
32	* Tcl_AddInterpResolvers --
33	*
34	* Adds a set of command/variable resolution procedures to an
35	* interpreter. These procedures are consulted when commands
36	* are resolved in Tcl_FindCommand, and when variables are
37	* resolved in TclLookupVar and LookupCompiledLocal. Each
38	* namespace may also have its own set of resolution procedures
39	* which take precedence over those for the interpreter.
40	*
41	* When a name is resolved, it is handled as follows. First,
42	* the name is passed to the resolution procedures for the
43	* namespace. If not resolved, the name is passed to each of
44	* the resolution procedures added to the interpreter. Finally,
45	* if still not resolved, the name is handled using the default
46	* Tcl rules for name resolution.
47	*
48	* Results:
49	* Returns pointers to the current name resolution procedures
50	* in the cmdProcPtr, varProcPtr and compiledVarProcPtr
51	* arguments.
52	*
53	* Side effects:
54	* If a compiledVarProc is specified, this procedure bumps the
55	* compileEpoch for the interpreter, forcing all code to be
56	* recompiled. If a cmdProc is specified, this procedure bumps
57	* the cmdRefEpoch in all namespaces, forcing commands to be
58	* resolved again using the new rules.
59	*
60	*----------------------------------------------------------------------
61	*/
62
63	void
64	Tcl_AddInterpResolvers(interp, name, cmdProc, varProc, compiledVarProc)
65
66	Tcl_Interp interp; / Interpreter whose name resolution
67	* rules are being modified. */
68	char name; / Name of this resolution scheme. */
69	Tcl_ResolveCmdProc cmdProc; / New procedure for command
70	* resolution */
71	Tcl_ResolveVarProc varProc; / Procedure for variable resolution
72	* at runtime */
73	Tcl_ResolveCompiledVarProc *compiledVarProc;
74	/* Procedure for variable resolution
75	* at compile time. */
76	{
77	Interp iPtr = (Interp)interp;
78	ResolverScheme *resPtr;
79
80	/*
81	* Since we're adding a new name resolution scheme, we must force
82	* all code to be recompiled to use the new scheme. If there
83	* are new compiled variable resolution rules, bump the compiler
84	* epoch to invalidate compiled code. If there are new command
85	* resolution rules, bump the cmdRefEpoch in all namespaces.
86	*/
87	if (compiledVarProc) {
88	iPtr->compileEpoch++;
89	}
90	if (cmdProc) {
91	BumpCmdRefEpochs(iPtr->globalNsPtr);
92	}
93
94	/*
95	* Look for an existing scheme with the given name. If found,
96	* then replace its rules.
97	*/
98	for (resPtr = iPtr->resolverPtr; resPtr != NULL; resPtr = resPtr->nextPtr) {
99	if (name == resPtr->name && strcmp(name, resPtr->name) == 0) {
100	resPtr->cmdResProc = cmdProc;
101	resPtr->varResProc = varProc;
102	resPtr->compiledVarResProc = compiledVarProc;
103	return;
104	}
105	}
106
107	/*
108	* Otherwise, this is a new scheme. Add it to the FRONT
109	* of the linked list, so that it overrides existing schemes.
110	*/
111	resPtr = (ResolverScheme *) ckalloc(sizeof(ResolverScheme));
112	resPtr->name = (char*)ckalloc((unsigned)(strlen(name)+1));
113	strcpy(resPtr->name, name);
114	resPtr->cmdResProc = cmdProc;
115	resPtr->varResProc = varProc;
116	resPtr->compiledVarResProc = compiledVarProc;
117	resPtr->nextPtr = iPtr->resolverPtr;
118	iPtr->resolverPtr = resPtr;
119	}
120
121	/*
122	*----------------------------------------------------------------------
123	*
124	* Tcl_GetInterpResolvers --
125	*
126	* Looks for a set of command/variable resolution procedures with
127	* the given name in an interpreter. These procedures are
128	* registered by calling Tcl_AddInterpResolvers.
129	*
130	* Results:
131	* If the name is recognized, this procedure returns non-zero,
132	* along with pointers to the name resolution procedures in
133	* the Tcl_ResolverInfo structure. If the name is not recognized,
134	* this procedure returns zero.
135	*
136	* Side effects:
137	* None.
138	*
139	*----------------------------------------------------------------------
140	*/
141
142	int
143	Tcl_GetInterpResolvers(interp, name, resInfoPtr)
144
145	Tcl_Interp interp; / Interpreter whose name resolution
146	* rules are being queried. */
147	char name; / Look for a scheme with this name. */
148	Tcl_ResolverInfo resInfoPtr; / Returns pointers to the procedures,
149	* if found */
150	{
151	Interp iPtr = (Interp)interp;
152	ResolverScheme *resPtr;
153
154	/*
155	* Look for an existing scheme with the given name. If found,
156	* then return pointers to its procedures.
157	*/
158	for (resPtr = iPtr->resolverPtr; resPtr != NULL; resPtr = resPtr->nextPtr) {
159	if (name == resPtr->name && strcmp(name, resPtr->name) == 0) {
160	resInfoPtr->cmdResProc = resPtr->cmdResProc;
161	resInfoPtr->varResProc = resPtr->varResProc;
162	resInfoPtr->compiledVarResProc = resPtr->compiledVarResProc;
163	return 1;
164	}
165	}
166
167	return 0;
168	}
169
170	/*
171	*----------------------------------------------------------------------
172	*
173	* Tcl_RemoveInterpResolvers --
174	*
175	* Removes a set of command/variable resolution procedures
176	* previously added by Tcl_AddInterpResolvers. The next time
177	* a command/variable name is resolved, these procedures
178	* won't be consulted.
179	*
180	* Results:
181	* Returns non-zero if the name was recognized and the
182	* resolution scheme was deleted. Returns zero otherwise.
183	*
184	* Side effects:
185	* If a scheme with a compiledVarProc was deleted, this procedure
186	* bumps the compileEpoch for the interpreter, forcing all code
187	* to be recompiled. If a scheme with a cmdProc was deleted,
188	* this procedure bumps the cmdRefEpoch in all namespaces,
189	* forcing commands to be resolved again using the new rules.
190	*
191	*----------------------------------------------------------------------
192	*/
193
194	int
195	Tcl_RemoveInterpResolvers(interp, name)
196
197	Tcl_Interp interp; / Interpreter whose name resolution
198	* rules are being modified. */
199	char name; / Name of the scheme to be removed. */
200	{
201	Interp iPtr = (Interp)interp;
202	ResolverScheme *prevPtrPtr, resPtr;
203
204	/*
205	* Look for an existing scheme with the given name.
206	*/
207	prevPtrPtr = &iPtr->resolverPtr;
208	for (resPtr = iPtr->resolverPtr; resPtr != NULL; resPtr = resPtr->nextPtr) {
209	if (name == resPtr->name && strcmp(name, resPtr->name) == 0) {
210	break;
211	}
212	prevPtrPtr = &resPtr->nextPtr;
213	}
214
215	/*
216	* If we found the scheme, delete it.
217	*/
218	if (resPtr) {
219	/*
220	* If we're deleting a scheme with compiled variable resolution
221	* rules, bump the compiler epoch to invalidate compiled code.
222	* If we're deleting a scheme with command resolution rules,
223	* bump the cmdRefEpoch in all namespaces.
224	*/
225	if (resPtr->compiledVarResProc) {
226	iPtr->compileEpoch++;
227	}
228	if (resPtr->cmdResProc) {
229	BumpCmdRefEpochs(iPtr->globalNsPtr);
230	}
231
232	*prevPtrPtr = resPtr->nextPtr;
233	ckfree(resPtr->name);
234	ckfree((char *) resPtr);
235
236	return 1;
237	}
238	return 0;
239	}
240
241	/*
242	*----------------------------------------------------------------------
243	*
244	* BumpCmdRefEpochs --
245	*
246	* This procedure is used to bump the cmdRefEpoch counters in
247	* the specified namespace and all of its child namespaces.
248	* It is used whenever name resolution schemes are added/removed
249	* from an interpreter, to invalidate all command references.
250	*
251	* Results:
252	* None.
253	*
254	* Side effects:
255	* Bumps the cmdRefEpoch in the specified namespace and its
256	* children, recursively.
257	*
258	*----------------------------------------------------------------------
259	*/
260
261	static void
262	BumpCmdRefEpochs(nsPtr)
263	Namespace nsPtr; / Namespace being modified. */
264	{
265	Tcl_HashEntry *entry;
266	Tcl_HashSearch search;
267	Namespace *childNsPtr;
268
269	nsPtr->cmdRefEpoch++;
270
271	for (entry = Tcl_FirstHashEntry(&nsPtr->childTable, &search);
272	entry != NULL;
273	entry = Tcl_NextHashEntry(&search)) {
274
275	childNsPtr = (Namespace *) Tcl_GetHashValue(entry);
276	BumpCmdRefEpochs(childNsPtr);
277	}
278	}
279
280
281	/*
282	*----------------------------------------------------------------------
283	*
284	* Tcl_SetNamespaceResolvers --
285	*
286	* Sets the command/variable resolution procedures for a namespace,
287	* thereby changing the way that command/variable names are
288	* interpreted. This allows extension writers to support different
289	* name resolution schemes, such as those for object-oriented
290	* packages.
291	*
292	* Command resolution is handled by a procedure of the following
293	* type:
294	*
295	* typedef int (Tcl_ResolveCmdProc) _ANSI_ARGS_((
296	* Tcl_Interp* interp, char* name, Tcl_Namespace *context,
297	* int flags, Tcl_Command *rPtr));
298	*
299	* Whenever a command is executed or Tcl_FindCommand is invoked
300	* within the namespace, this procedure is called to resolve the
301	* command name. If this procedure is able to resolve the name,
302	* it should return the status code TCL_OK, along with the
303	* corresponding Tcl_Command in the rPtr argument. Otherwise,
304	* the procedure can return TCL_CONTINUE, and the command will
305	* be treated under the usual name resolution rules. Or, it can
306	* return TCL_ERROR, and the command will be considered invalid.
307	*
308	* Variable resolution is handled by two procedures. The first
309	* is called whenever a variable needs to be resolved at compile
310	* time:
311	*
312	* typedef int (Tcl_ResolveCompiledVarProc) _ANSI_ARGS_((
313	* Tcl_Interp* interp, char* name, Tcl_Namespace *context,
314	* Tcl_ResolvedVarInfo *rPtr));
315	*
316	* If this procedure is able to resolve the name, it should return
317	* the status code TCL_OK, along with variable resolution info in
318	* the rPtr argument; this info will be used to set up compiled
319	* locals in the call frame at runtime. The procedure may also
320	* return TCL_CONTINUE, and the variable will be treated under
321	* the usual name resolution rules. Or, it can return TCL_ERROR,
322	* and the variable will be considered invalid.
323	*
324	* Another procedure is used whenever a variable needs to be
325	* resolved at runtime but it is not recognized as a compiled local.
326	* (For example, the variable may be requested via
327	* Tcl_FindNamespaceVar.) This procedure has the following type:
328	*
329	* typedef int (Tcl_ResolveVarProc) _ANSI_ARGS_((
330	* Tcl_Interp* interp, char* name, Tcl_Namespace *context,
331	* int flags, Tcl_Var *rPtr));
332	*
333	* This procedure is quite similar to the compile-time version.
334	* It returns the same status codes, but if variable resolution
335	* succeeds, this procedure returns a Tcl_Var directly via the
336	* rPtr argument.
337	*
338	* Results:
339	* Nothing.
340	*
341	* Side effects:
342	* Bumps the command epoch counter for the namespace, invalidating
343	* all command references in that namespace. Also bumps the
344	* resolver epoch counter for the namespace, forcing all code
345	* in the namespace to be recompiled.
346	*
347	*----------------------------------------------------------------------
348	*/
349
350	void
351	Tcl_SetNamespaceResolvers(namespacePtr, cmdProc, varProc, compiledVarProc)
352	Tcl_Namespace namespacePtr; / Namespace whose resolution rules
353	* are being modified. */
354	Tcl_ResolveCmdProc cmdProc; / Procedure for command resolution */
355	Tcl_ResolveVarProc varProc; / Procedure for variable resolution
356	* at runtime */
357	Tcl_ResolveCompiledVarProc *compiledVarProc;
358	/* Procedure for variable resolution
359	* at compile time. */
360	{
361	Namespace nsPtr = (Namespace)namespacePtr;
362
363	/*
364	* Plug in the new command resolver, and bump the epoch counters
365	* so that all code will have to be recompiled and all commands
366	* will have to be resolved again using the new policy.
367	*/
368	nsPtr->cmdResProc = cmdProc;
369	nsPtr->varResProc = varProc;
370	nsPtr->compiledVarResProc = compiledVarProc;
371
372	nsPtr->cmdRefEpoch++;
373	nsPtr->resolverEpoch++;
374	}
375
376	/*
377	*----------------------------------------------------------------------
378	*
379	* Tcl_GetNamespaceResolvers --
380	*
381	* Returns the current command/variable resolution procedures
382	* for a namespace. By default, these procedures are NULL.
383	* New procedures can be installed by calling
384	* Tcl_SetNamespaceResolvers, to provide new name resolution
385	* rules.
386	*
387	* Results:
388	* Returns non-zero if any name resolution procedures have been
389	* assigned to this namespace; also returns pointers to the
390	* procedures in the Tcl_ResolverInfo structure. Returns zero
391	* otherwise.
392	*
393	* Side effects:
394	* None.
395	*
396	*----------------------------------------------------------------------
397	*/
398
399	int
400	Tcl_GetNamespaceResolvers(namespacePtr, resInfoPtr)
401
402	Tcl_Namespace namespacePtr; / Namespace whose resolution rules
403	* are being modified. */
404	Tcl_ResolverInfo resInfoPtr; / Returns: pointers for all
405	* name resolution procedures
406	* assigned to this namespace. */
407	{
408	Namespace nsPtr = (Namespace)namespacePtr;
409
410	resInfoPtr->cmdResProc = nsPtr->cmdResProc;
411	resInfoPtr->varResProc = nsPtr->varResProc;
412	resInfoPtr->compiledVarResProc = nsPtr->compiledVarResProc;
413
414	if (nsPtr->cmdResProc != NULL \|\|
415	nsPtr->varResProc != NULL \|\|
416	nsPtr->compiledVarResProc != NULL) {
417	return 1;
418	}
419	return 0;
420	}
421
422
423	/* $History: tclresolve.c $
424	*
425	* *************** Version 1 ***************
426	* User: Dtashley Date: 1/02/01 Time: 1:04a
427	* Created in $/IjuScripter, IjuConsole/Source/Tcl Base
428	* Initial check-in.
429	*/
430
431	/* End of TCLRESOLVE.C */