Tcl_GetClassAsObject man page on Alpinelinux

Man page or keyword search:  
man Server   18016 pages
apropos Keyword Search (all sections)
Output format
Alpinelinux logo
[printable version]

Tcl_Class(3)		    TclOO Library Functions		  Tcl_Class(3)

______________________________________________________________________________

NAME
       Tcl_ClassGetMetadata,   Tcl_ClassSetMetadata,   Tcl_CopyObjectInstance,
       Tcl_GetClassAsObject,	Tcl_GetObjectAsClass,	 Tcl_GetObjectCommand,
       Tcl_GetObjectFromObj,	 Tcl_GetObjectName,    Tcl_GetObjectNamespace,
       Tcl_NewObjectInstance,	 Tcl_ObjectDeleted,	Tcl_ObjectGetMetadata,
       Tcl_ObjectGetMethodNameMapper,	Tcl_ObjectSetMetadata,	Tcl_ObjectSet‐
       MethodNameMapper - manipulate objects and classes

SYNOPSIS
       #include <tclOO.h>

       Tcl_Object
       Tcl_GetObjectFromObj(interp, objPtr)

       Tcl_Object
       Tcl_GetClassAsObject(class)

       Tcl_Class
       Tcl_GetObjectAsClass(object)

       Tcl_Obj *
       Tcl_GetObjectName(interp, object)

       Tcl_Command
       Tcl_GetObjectCommand(object)

       Tcl_Namespace *
       Tcl_GetObjectNamespace(object)

       Tcl_Object
       Tcl_NewObjectInstance(interp, class, name, nsName, objc, objv, skip)

       Tcl_Object
       Tcl_CopyObjectInstance(interp, object, name, nsName)

       int
       Tcl_ObjectDeleted(object)

       ClientData
       Tcl_ObjectGetMetadata(object, metaTypePtr)

       Tcl_ObjectSetMetadata(object, metaTypePtr, metadata)

       ClientData
       Tcl_ClassGetMetadata(class, metaTypePtr)

       Tcl_ClassSetMetadata(class, metaTypePtr, metadata)

       Tcl_ObjectMapMethodNameProc
       Tcl_ObjectGetMethodNameMapper(object)

       Tcl_ObjectSetMethodNameMapper(object, methodNameMapper)

ARGUMENTS
       Tcl_Interp *interp (in/out)	 Interpreter providing the context for
					 looking up or creating an object, and
					 into whose result error messages will
					 be written on failure.

       Tcl_Obj *objPtr (in)		 The name of the object to look up.

       Tcl_Object object (in)		 Reference  to	the  object to operate
					 upon.

       Tcl_Class class (in)		 Reference to  the  class  to  operate
					 upon.

       const char *name (in)		 The  name of the object to create, or
					 NULL if a new unused name  is	to  be
					 automatically selected.

       const char *nsName (in)		 The  name  of the namespace to create
					 for the object's private use, or NULL
					 if  a	new unused name is to be auto‐
					 matically selected.

       int objc (in)			 The number of elements	 in  the  objv
					 array.

       Tcl_Obj *const *objv (in)	 The  arguments to the command to cre‐
					 ate the instance of the class.

       int skip (in)			 The number of arguments at the	 start
					 of the argument array, objv, that are
					 not arguments to any constructors.

       Tcl_ObjectMetadataType *metaTypePtr (in)
					 The type of metadata being  set  with
					 Tcl_ClassSetMetadata	or   retrieved
					 with Tcl_ClassGetMetadata.

       ClientData metadata (in)		 An item of metadata to attach to  the
					 class, or NULL to remove the metadata
					 associated    with    a    particular
					 metaTypePtr.

       Tcl_ObjectMapMethodNameProc methodNameMapper (in)
					 A  pointer  to	 a function to call to
					 adjust the  mapping  of  objects  and
					 method	 names	to implementations, or
					 NULL  when   no   such	  mapping   is
					 required.
_________________________________________________________________

DESCRIPTION
       Objects	are  typed  entities that have a set of operations ("methods")
       associated with them. Classes are objects that can manufacture objects.
       Each  class  can	 be viewed as an object itself; the object view can be
       retrieved using Tcl_GetClassAsObject which always  returns  the	object
       when applied to a non-destroyed class, and an object can be viewed as a
       class with the aid of the Tcl_GetObjectAsClass  (which  either  returns
       the  class,  or	NULL  if  the object is not a class). An object may be
       looked up using the Tcl_GetObjectFromObj function, which either returns
       an  object or NULL (with an error message in the interpreter result) if
       the object cannot be found. The correct way to look up a class by  name
       is  to look up the object with that name, and then to use Tcl_GetObjec‐
       tAsClass.

       Every object has its own command and namespace associated with it.  The
       command	may  be retrieved using the Tcl_GetObjectCommand function, the
       name of the object (and hence the name of the command) with  Tcl_GetOb‐
       jectName,  and  the namespace may be retrieved using the Tcl_GetObject‐
       Namespace  function.  Note  that	 the  Tcl_Obj  reference  returned  by
       Tcl_GetObjectName is a shared reference.

       Instances  of  classes  are  created using Tcl_NewObjectInstance, which
       takes creates an object from any class (and which is internally	called
       by  both	 the  create and new methods of the oo::class class). It takes
       parameters that optionally give the name of the object and namespace to
       create,	and  which  describe the arguments to pass to the class's con‐
       structor (if any). The result of the function will be either  a	refer‐
       ence  to the newly created object, or NULL if the creation failed (when
       an error message will be left in the interpreter result). In  addition,
       objects	may  be copied by using Tcl_CopyObjectInstance which creates a
       copy of an object without running any constructors.

OBJECT AND CLASS METADATA
       Every object and every class may have  arbitrary	 amounts  of  metadata
       attached to it, which the object or class attaches no meaning to beyond
       what is described in a Tcl_ObjectMetadataType structure instance. Meta‐
       data  to be attached is described by the type of the metadata (given in
       the metaTypePtr argument) and an arbitrary pointer (the metadata	 argu‐
       ment) that are given to Tcl_ObjectSetMetadata and Tcl_ClassSetMetadata,
       and a particular piece of metadata can  be  retrieved  given  its  type
       using  Tcl_ObjectGetMetadata  and Tcl_ClassGetMetadata. If the metadata
       parameter to either Tcl_ObjectSetMetadata  or  Tcl_ClassSetMetadata  is
       NULL,  the  metadata  is removed if it was attached, and the results of
       Tcl_ObjectGetMetadata and Tcl_ClassGetMetadata are NULL	if  the	 given
       type  of	 metadata  was	not attached. It is not an error to request or
       remove a piece of metadata that was not attached.

   TCL_OBJECTMETADATATYPE STRUCTURE
       The contents of the Tcl_ObjectMetadataType structure are as follows:

	      typedef const struct {
		  int version;
		  const char *name;
		  Tcl_ObjectMetadataDeleteProc *deleteProc;
		  Tcl_CloneProc *cloneProc;
	      } Tcl_ObjectMetadataType;

       The version field allows for future expansion  of  the  structure,  and
       should always be declared equal to TCL_OO_METADATA_VERSION_CURRENT. The
       name field provides a human-readable name for the type, and is reserved
       for debugging.

       The   deleteProc	  field	 gives	a  function  of	 type  Tcl_ObjectMeta‐
       dataDeleteProc that is used to delete a particular piece	 of  metadata,
       and  is	called	when the attached metadata is replaced or removed; the
       field must not be NULL.

       The cloneProc field gives a function that is used to copy  a  piece  of
       metadata	 (used	when  a copy of an object is created using Tcl_CopyOb‐
       jectInstance); if NULL, the metadata will be just directly copied.

   TCL_OBJECTMETADATADELETEPROC FUNCTION SIGNATURE
       Functions matching this signature are used to delete  metadata  associ‐
       ated with a class or object.

	      typedef void Tcl_ObjectMetadataDeleteProc(
		      ClientData metadata);

       The metadata argument gives the address of the metadata to be deleted.

   TCL_CLONEPROC FUNCTION SIGNATURE
       Functions matching this signature are used to create copies of metadata
       associated with a class or object.

	      typedef int Tcl_CloneProc(
		      Tcl_Interp *interp,
		      ClientData srcMetadata,
		      ClientData *dstMetadataPtr);

       The interp argument gives a place to write an error  message  when  the
       attempt	to clone the object is to fail, in which case the clone proce‐
       dure must also return TCL_ERROR; it  should  return  TCL_OK  otherwise.
       The  srcMetadata	 argument  gives  the  address	of  the metadata to be
       cloned, and the cloned metadata should be  written  into	 the  variable
       pointed	to by dstMetadataPtr; a NULL should be written if the metadata
       is to not be cloned but the overall object copy operation is  still  to
       succeed.

OBJECT METHOD NAME MAPPING
       It  is  possible	 to  control,  on a per-object basis, what methods are
       invoked when a particular method is invoked. Normally this is  done  by
       looking	up the method name in the object and then in the class hierar‐
       chy, but fine control of exactly what the value	used  to  perform  the
       look  up	 is  afforded  through the ability to set a method name mapper
       callback via Tcl_ObjectSetMethodNameMapper (and its introspection coun‐
       terpart,	 Tcl_ObjectGetMethodNameMapper, which returns the current map‐
       per). The current mapper (if any) is invoked immediately before looking
       up what chain of method implementations is to be used.

   TCL_OBJECTMAPMETHODNAMEPROC FUNCTION SIGNATURE
       The Tcl_ObjectMapMethodNameProc callback is defined as follows:

	      typedef int Tcl_ObjectMapMethodNameProc(
		      Tcl_Interp *interp,
		      Tcl_Object object,
		      Tcl_Class *startClsPtr,
		      Tcl_Obj *methodNameObj);

       If the result is TCL_OK, the remapping is assumed to have been done. If
       the result is TCL_ERROR, an error message will have been left in interp
       and the method call will fail. If the result is TCL_BREAK, the standard
       method name lookup rules will be used; the  behavior  of	 other	result
       codes is currently undefined. The object parameter says which object is
       being processed. The startClsPtr parameter points to  a	variable  that
       contains the first class to provide a definition in the method chain to
       process, or NULL if the whole chain is to be  processed	(the  argument
       itself  is  never  NULL); this variable may be updated by the callback.
       The methodNameObj parameter gives an  unshared  object  containing  the
       name  of the method being invoked, as provided by the user; this object
       may be updated by the callback.

SEE ALSO
       Method(3), oo::class(n), oo::copy(n), oo::define(n), oo::object(n)

KEYWORDS
       class, constructor, object

TclOO				      0.1			  Tcl_Class(3)
[top]

List of man pages available for Alpinelinux

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net