Tcl_CreateEnsemble, Tcl_FindEnsemble, Tcl_GetEnsembleFlags,
Tcl_GetEnsembleMappingDict, Tcl_GetEnsembleNamespace,
Tcl_GetEnsembleParameterList, Tcl_GetEnsembleUnknownHandler,
Tcl_GetEnsembleSubcommandList, Tcl_IsEnsemble, Tcl_SetEnsembleFlags,
Tcl_SetEnsembleMappingDict, Tcl_SetEnsembleParameterList,
Tcl_SetEnsembleSubcommandList, Tcl_SetEnsembleUnknownHandler - manipulate
ensemble commands
#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)
- Tcl_Interp *interp (in/out)
- The interpreter in which the ensemble is to be created or found. Also
where error result messages are written. The functions whose names start
with Tcl_GetEnsemble 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 ORed set of flag bits describing the basic configuration of the
ensemble. Currently only one bit has meaning, TCL_ENSEMBLE_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 ORed 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 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 implementation 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 dictionary or the unknown subcommand
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.
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 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.
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 token 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 ensemble's bound namespace. Defaults to NULL. May be read and
written using Tcl_GetEnsembleMappingDict 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 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 ensemble between
the name of the ensemble and the subcommand argument. 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 obtained
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 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_GetEnsembleSubcommandList 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 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_GetEnsembleUnknownHandler 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 refer to an
ensemble).