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Tcl_Ensemble(3) Tcl Library Procedures Tcl_Ensemble(3) ________________________________________________________________________________ NAME Tcl_CreateEnsemble, Tcl_FindEnsemble, Tcl_GetEnsembleFlags, Tcl_GetEnsem- bleMappingDict, Tcl_GetEnsembleNamespace, Tcl_GetEnsembleParameterList, Tcl_GetEnsembleUnknownHandler, Tcl_GetEnsembleSubcommandList, Tcl_IsEnsem- ble, Tcl_SetEnsembleFlags, Tcl_SetEnsembleMappingDict, Tcl_SetEnsemblePara- meterList, Tcl_SetEnsembleSubcommandList, Tcl_SetEnsembleUnknownHandler - manipulate ensemble commands SYNOPSIS #include <tcl.h> Tcl_Command Tcl_CreateEnsemble(interp, name, namespacePtr, ensFlags) Tcl_Command Tcl_FindEnsemble(interp, cmdNameObj, flags) int Tcl_IsEnsemble(token) int Tcl_GetEnsembleFlags(interp, token, ensFlagsPtr) int Tcl_SetEnsembleFlags(interp, token, ensFlags) int Tcl_GetEnsembleMappingDict(interp, token, dictObjPtr) int Tcl_SetEnsembleMappingDict(interp, token, dictObj) int 2 Tcl_GetEnsembleParameterList(interp, token, listObjPtr) 2 int 2 Tcl_SetEnsembleParameterList(interp, token, listObj) 2 int Tcl_GetEnsembleSubcommandList(interp, token, listObjPtr) int Tcl_SetEnsembleSubcommandList(interp, token, listObj) int Tcl_GetEnsembleUnknownHandler(interp, token, listObjPtr) int Tcl_SetEnsembleUnknownHandler(interp, token, listObj) int Tcl_GetEnsembleNamespace(interp, token, namespacePtrPtr) ARGUMENTS Tcl_Interp *interp (in/out) The interpreter in which the ensemble is to be created or found. Also where error re- sult messages are written. The functions whose names start with Tcl_GetEnsemble may have a NULL for the in- terp, but all other functions must not. const char *name (in) The name of the ensemble com- mand to be created. Tcl_Namespace *namespacePtr (in) The namespace to which the ensemble command is to be bound, or NULL for the cur- rent namespace. int ensFlags (in) An OR'ed set of flag bits de- scribing the basic configura- tion of the ensemble. Cur- rently only one bit has mean- ing, TCL_ENSEMBLE_PREFIX, which is present when the en- semble command should also match unambiguous prefixes of subcommands. Tcl_Obj *cmdNameObj (in) A value holding the name of the ensemble command to look up. int flags (in) An OR'ed set of flag bits controlling the behavior of Tcl_FindEnsemble. Currently only TCL_LEAVE_ERR_MSG is supported. Tcl_Command token (in) A normal command token that refers to an ensemble com- mand, or which you wish to use for testing as an ensem- ble command in Tcl_IsEnsem- ble. int *ensFlagsPtr (out) Pointer to a variable into which to write the current ensemble flag bits; currently only the bit TCL_ENSEM- BLE_PREFIX is defined. Tcl_Obj *dictObj (in) A dictionary value to use for the subcommand to implementa- tion command prefix mapping dictionary in the ensemble. May be NULL if the mapping dictionary is to be removed. Tcl_Obj **dictObjPtr (out) Pointer to a variable into which to write the current ensemble mapping dictionary. Tcl_Obj *listObj (in) A list value to use for the list of formal pre-subcommand parameters, the defined list of subcommands in the dictio- nary or the unknown subcom- mand handler command prefix. May be NULL if the subcommand list or unknown handler are to be removed. Tcl_Obj **listObjPtr (out) Pointer to a variable into which to write the current list of formal pre-subcommand parameters, the defined list of subcommands or the current unknown handler prefix. Tcl_Namespace **namespacePtrPtr (out) Pointer to a variable into which to write the handle of the namespace to which the ensemble is bound. ________________________________________________________________________________ DESCRIPTION An ensemble is a command, bound to some namespace, which consists of a col- lection of subcommands implemented by other Tcl commands. The first argu- ment to the ensemble command is always interpreted as a selector that states what subcommand to execute. Ensembles are created using Tcl_CreateEnsemble, which takes four arguments: the interpreter to work within, the name of the ensemble to create, the namespace within the interpreter to bind the ensemble to, and the default set of ensemble flags. The result of the function is the command token for the ensemble, which may be used to further configure the ensemble using the API described below in ENSEMBLE PROPERTIES. Given the name of an ensemble command, the token for that command may be retrieved using Tcl_FindEnsemble. If the given command name (in cmdNameObj) does not refer to an ensemble command, the result of the function is NULL and (if the TCL_LEAVE_ERR_MSG bit is set in flags) an error message is left in the interpreter result. A command token may be checked to see if it refers to an ensemble using Tcl_IsEnsemble. This returns 1 if the token refers to an ensemble, or 0 otherwise. ENSEMBLE PROPERTIES Every ensemble has four read-write properties and a read-only property. The properties are: flags (read-write) The set of flags for the ensemble, expressed as a bit-field. Cur- rently, the only public flag is TCL_ENSEMBLE_PREFIX which is set when unambiguous prefixes of subcommands are permitted to be re- solved to implementations as well as exact matches. The flags may be read and written using Tcl_GetEnsembleFlags and Tcl_SetEnsembleFlags respectively. The result of both of those functions is a Tcl result code (TCL_OK, or TCL_ERROR if the token does not refer to an ensem- ble). mapping dictionary (read-write) A dictionary containing a mapping from subcommand names to lists of words to use as a command prefix (replacing the first two words of the command which are the ensemble command itself and the subcommand name), or NULL if every subcommand is to be mapped to the command with the same unqualified name in the ensemble's bound namespace. Defaults to NULL. May be read and written using Tcl_GetEnsembleMap- pingDict and Tcl_SetEnsembleMappingDict respectively. The result of both of those functions is a Tcl result code (TCL_OK, or TCL_ERROR if the token does not refer to an ensemble) and the dictionary ob- tained from Tcl_GetEnsembleMappingDict should always be treated as immutable even if it is unshared. All command names in prefixes set via Tcl_SetEnsembleMappingDict must be fully qualified. formal pre-subcommand parameter list (read-write) A list of formal parameter names (the names only being used when 2 generating error messages) that come at invocation of the ensemble 2 between the name of the ensemble and the subcommand argument. NULL 2 (the default) is equivalent to the empty list. May be read and writ- 2 ten using Tcl_GetEnsembleParameterList and Tcl_SetEnsembleParame- 2 terList respectively. The result of both of those functions is a Tcl 2 result code (TCL_OK, or TCL_ERROR if the token does not refer to an 2 ensemble) and the dictionary obtained from Tcl_GetEnsembleParame- 2 terList should always be treated as immutable even if it is un- 2 shared. subcommand list (read-write) A list of all the subcommand names for the ensemble, or NULL if this is to be derived from either the keys of the mapping dictionary (see above) or (if that is also NULL) from the set of commands exported by the bound namespace. May be read and written using Tcl_GetEnsem- bleSubcommandList and Tcl_SetEnsembleSubcommandList respectively. The result of both of those functions is a Tcl result code (TCL_OK, or TCL_ERROR if the token does not refer to an ensemble) and the list obtained from Tcl_GetEnsembleSubcommandList should always be treated as immutable even if it is unshared. unknown subcommand handler command prefix (read-write) A list of words to prepend on the front of any subcommand when the subcommand is unknown to the ensemble (according to the current pre- fix handling rule); see the namespace ensemble command for more de- tails. If NULL, the default behavior - generate a suitable error message - will be used when an unknown subcommand is encountered. May be read and written using Tcl_GetEnsembleUnknownHandler and Tcl_SetEnsembleUnknownHandler respectively. The result of both func- tions is a Tcl result code (TCL_OK, or TCL_ERROR if the token does not refer to an ensemble) and the list obtained from Tcl_GetEnsem- bleUnknownHandler should always be treated as immutable even if it is unshared. bound namespace (read-only) The namespace to which the ensemble is bound; when the namespace is deleted, so too will the ensemble, and this namespace is also the namespace whose list of exported commands is used if both the map- ping dictionary and the subcommand list properties are NULL. May be read using Tcl_GetEnsembleNamespace which returns a Tcl result code (TCL_OK, or TCL_ERROR if the token does not refer to an ensemble). SEE ALSO namespace(n), Tcl_DeleteCommandFromToken(3) KEYWORDS command, ensemble Tcl 8.5 Tcl_Ensemble(3)
NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | SEE ALSO | KEYWORDS
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