FreeBSD Manual Pages
Tcl_Ensemble(3) Tcl Library Procedures Tcl_Ensemble(3) ______________________________________________________________________________ NAME Tcl_CreateEnsemble, Tcl_FindEnsemble, Tcl_GetEnsembleFlags, Tcl_GetEnsembleMappingDict, Tcl_GetEnsembleNamespace, Tcl_GetEnsem- bleParameterList, Tcl_GetEnsembleUnknownHandler, Tcl_GetEnsembleSubcom- mandList, Tcl_IsEnsemble, Tcl_SetEnsembleFlags, Tcl_SetEnsembleMapping- Dict, Tcl_SetEnsembleParameterList, 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 Tcl_GetEnsembleParameterList(interp, token, listObjPtr) int Tcl_SetEnsembleParameterList(interp, token, listObj) 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 result mes- sages are written. The functions whose names start with Tcl_GetEnsem- ble may have a NULL for the interp, but all other functions must not. const char *name (in) The name of the ensemble command to be created. Tcl_Namespace *namespacePtr (in) The namespace to which the ensemble command is to be bound, or NULL for the current namespace. int ensFlags (in) An OR'ed set of flag bits describing the basic con- figuration of the ensem- ble. Currently only one bit has meaning, TCL_EN- SEMBLE_PREFIX, which is present when the ensemble 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. Cur- rently only TCL_LEAVE_ERR_MSG is sup- ported. Tcl_Command token (in) A normal command token that refers to an ensem- ble command, or which you wish to use for testing as an ensemble command in Tcl_IsEnsemble. int *ensFlagsPtr (out) Pointer to a variable into which to write the current ensemble flag bits; currently only the bit TCL_ENSEMBLE_PREFIX is defined. Tcl_Obj *dictObj (in) A dictionary value to use for the subcommand to im- plementation command pre- fix 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 sub- commands in the dictio- nary or the unknown sub- command 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 parame- ters, the defined list of subcommands or the cur- rent unknown handler pre- fix. 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 collection of subcommands implemented by other Tcl commands. The first argument 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 argu- ments: the interpreter to work within, the name of the ensemble to cre- ate, 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 cmd- NameObj) does not refer to an ensemble command, the result of the func- tion is NULL and (if the TCL_LEAVE_ERR_MSG bit is set in flags) an er- ror 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. Currently, the only public flag is TCL_ENSEMBLE_PREFIX which is set when unambiguous prefixes of subcommands are permitted to be resolved 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 to- ken does not refer to an ensemble). 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 en- semble's bound namespace. Defaults to NULL. May be read and written using Tcl_GetEnsembleMappingDict and Tcl_SetEnsembleMap- pingDict 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 obtained 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 generating error messages) that come at invocation of the ensem- ble between the name of the ensemble and the subcommand argu- ment. NULL (the default) is equivalent to the empty list. May be read and written using Tcl_GetEnsembleParameterList and Tcl_SetEnsembleParameterList 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_GetEnsembleParameterList should always be treated as immutable even if it is unshared. 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 dic- tionary (see above) or (if that is also NULL) from the set of commands exported by the bound namespace. May be read and writ- ten using Tcl_GetEnsembleSubcommandList and Tcl_SetEnsembleSub- commandList 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_GetEnsem- bleSubcommandList 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 cur- rent prefix handling rule); see the namespace ensemble command for more details. 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_GetEnsembleUn- knownHandler and Tcl_SetEnsembleUnknownHandler respectively. The result of both 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_GetEnsembleUnknownHandler 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 mapping 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 re- fer to an ensemble). REFERENCE COUNT MANAGEMENT Tcl_FindEnsemble does not modify the reference count of its cmdNameObj argument; it only reads. Note however that this function may set the interpreter result; if that is the only place that is holding a refer- ence to the object, it will be deleted. The ensemble property getters (Tcl_GetEnsembleMappingDict, Tcl_GetEnsembleParameterList, Tcl_GetEnsembleSubcommandList, and Tcl_GetEnsembleUnknownHandler) do not manipulate the reference count of the values they provide out; if those are non-NULL, they will have a reference count of at least 1. Note that these functions may set the interpreter result. The ensemble property setters (Tcl_SetEnsembleMappingDict, Tcl_SetEnsembleParameterList, Tcl_SetEnsembleSubcommandList, and Tcl_SetEnsembleUnknownHandler) will increment the reference count of the new value of the property they are given if they succeed (and decrement the reference count of the old value of the property, if rel- evant). If the property setters return TCL_ERROR, the reference count of the Tcl_Obj argument is left unchanged. SEE ALSO namespace(n), Tcl_DeleteCommandFromToken(3) KEYWORDS command, ensemble Tcl 8.5 Tcl_Ensemble(3)
NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | REFERENCE COUNT MANAGEMENT | SEE ALSO | KEYWORDS
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=Tcl_SetEnsembleSubcommandList.tcl90&sektion=3&manpath=FreeBSD+Ports+14.3.quarterly>