Tcl_SetAssocData(3) Tcl Library Procedures Tcl_SetAssocData(3)
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NAME
Tcl_GetAssocData, Tcl_SetAssocData, Tcl_DeleteAssocData - manage associations of string keys and user
specified data with Tcl interpreters.
SYNOPSIS
#include <tcl.h>
ClientData
Tcl_GetAssocData(interp, key, delProcPtr)
Tcl_SetAssocData(interp, key, delProc, clientData)
Tcl_DeleteAssocData(interp, key)
ARGUMENTS
Tcl_Interp *interp (in) Interpreter in which to execute the specified command. |
CONST |
char *key (in) | |
Key for association with which to store data or from
which to delete or retrieve data. Typically the mod-ule module
ule prefix for a package.
Tcl_InterpDeleteProc *delProc (in) Procedure to call when interp is deleted.
Tcl_InterpDeleteProc **delProcPtr (in) Pointer to location in which to store address of cur-rent current
rent deletion procedure for association. Ignored if
NULL.
ClientData clientData (in) Arbitrary one-word value associated with the given key
in this interpreter. This data is owned by the
caller.
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DESCRIPTION
These procedures allow extensions to associate their own data with a Tcl interpreter. An association
consists of a string key, typically the name of the extension, and a one-word value, which is typi-cally typically
cally a pointer to a data structure holding data specific to the extension. Tcl makes no interpreta-tion interpretation
tion of either the key or the value for an association.
Storage management is facilitated by storing with each association a procedure to call when the
interpreter is deleted. This procedure can dispose of the storage occupied by the client's data in
any way it sees fit.
Tcl_SetAssocData creates an association between a string key and a user specified datum in the given
interpreter. If there is already an association with the given key, Tcl_SetAssocData overwrites it
with the new information. It is up to callers to organize their use of names to avoid conflicts, for
example, by using package names as the keys. If the deleteProc argument is non-NULL it specifies the
address of a procedure to invoke if the interpreter is deleted before the association is deleted.
DeleteProc should have arguments and result that match the type Tcl_InterpDeleteProc:
typedef void Tcl_InterpDeleteProc(
ClientData clientData,
Tcl_Interp *interp);
When deleteProc is invoked the clientData and interp arguments will be the same as the corresponding
arguments passed to Tcl_SetAssocData. The deletion procedure will not be invoked if the association
is deleted before the interpreter is deleted.
Tcl_GetAssocData returns the datum stored in the association with the specified key in the given
interpreter, and if the delProcPtr field is non-NULL, the address indicated by it gets the address of
the delete procedure stored with this association. If no association with the specified key exists in
the given interpreter Tcl_GetAssocData returns NULL.
Tcl_DeleteAssocData deletes an association with a specified key in the given interpreter. Then it
calls the deletion procedure.
KEYWORDS
association, data, deletion procedure, interpreter, key
Tcl 7.5 Tcl_SetAssocData(3)
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