path: root/doc/info.n

'\"
'\" Copyright (c) 1993 The Regents of the University of California.
'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
'\" Copyright (c) 1993-1997 Bell Labs Innovations for Lucent Technologies
'\" Copyright (c) 1998-2000 Ajuba Solutions
'\" Copyright (c) 2007-2012 Donal K. Fellows
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\"
.TH info n 8.4 Tcl "Tcl Built-In Commands"
.so man.macros
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
info \- Information about the state of the Tcl interpreter
.SH SYNOPSIS
\fBinfo \fIoption \fR?\fIarg arg ...\fR?
.BE
.SH DESCRIPTION
.PP
Available commands:
.TP
\fBinfo args \fIprocname\fR
.
Returns the names of the parameters to the procedure named \fIprocname\fR.
.TP
\fBinfo body \fIprocname\fR
.
Returns the body of the procedure named \fIprocname\fR.
.TP
\fBinfo class\fI subcommand class\fR ?\fIarg ...\fR
.
Returns information about the class named \fIclass\fR.
See \fBCLASS INTROSPECTION\fR below.
.TP
\fBinfo cmdcount\fR
.
Returns the total number of commands evaluated in this interpreter.
.TP
\fBinfo cmdtype \fIcommandName\fR
.VS TIP426
Returns a the type of the command named \fIcommandName\fR.
Built-in types are:
.RS
.IP \fBalias\fR
\fIcommandName\fR was created by \fBinterp alias\fR.
In a safe interpreter an alias is only visible if both the alias and the
target are visible.
.IP \fBcoroutine\fR
\fIcommandName\fR was created by \fBcoroutine\fR.
.IP \fBensemble\fR
\fIcommandName\fR was created by \fBnamespace ensemble\fR.
.IP \fBimport\fR
\fIcommandName\fR was created by \fBnamespace import\fR.
.IP \fBnative\fR
\fIcommandName\fR was created by the \fBTcl_CreateObjProc\fR
interface directly without further registration of the type of command.
.IP \fBobject\fR
\fIcommandName\fR is the public command that represents an
instance of \fBoo::object\fR or one of its subclasses.
.IP \fBprivateObject\fR
\fIcommandName\fR is the private command, \fBmy\fR by default,
that represents an instance of \fBoo::object\fR or one of its subclasses.
.IP \fBproc\fR
\fIcommandName\fR was created by \fBproc\fR.
.IP \fBinterp\fR
\fIcommandName\fR was created by \fBinterp create\fR.
.IP \fBzlibStream\fR
\fIcommandName\fR was created by \fBzlib stream\fR.
.PP
Other types may be also registered as well.  See \fBTcl_RegisterCommandTypeName\fR.
.RE
.VE TIP426
.TP
\fBinfo commands \fR?\fIpattern\fR?
.
Returns the names of all commands visible in the current namespace.  If
\fIpattern\fR is given, returns only those names that match according to
\fBstring match\fR.  Only the last component of \fIpattern\fR is a pattern.
Other components identify a namespace.  See \fBNAMESPACE RESOLUTION\fR in the
\fBnamespace\fR(n) documentation.
.TP
\fBinfo complete \fIcommand\fR
.
Returns 1 if \fIcommand\fR is a complete command, and \fB0\fR otherwise.
Typically used in line-oriented input environments
to allow users to type in commands that span multiple lines.
.TP
\fBinfo coroutine\fR
.
Returns the name of the current \fBcoroutine\fR, or the empty
string if there is no current coroutine or the current coroutine
has been deleted.
.TP
\fBinfo default \fIprocname parameter varname\fR
.
If the parameter \fIparameter\fR for the procedure named \fIprocname\fR has a
default value, stores that value in \fIvarname\fR and returns \fB1\fR.
Otherwise, returns \fB0\fR.
.TP
\fBinfo errorstack \fR?\fIinterp\fR?
.
Returns a description of the active command at each level for the
last error in the current interpreter, or in the interpreter named
\fIinterp\fR if given.
.RS
.PP
The description is a dictionary of tokens and parameters. Tokens are
currently either \fBCALL\fR, \fBUP\fR, or \fBINNER\fR, but other values may be
introduced in the future. \fBCALL\fR indicates a command call, and its
parameter is the corresponding \fBinfo level\fR \fB0\fR. \fBUP\fR indicates a
shift in variable frames generated by \fBuplevel\fR or similar, and applies to
the previous \fBCALL\fR item. Its parameter is the level offset. \fBINNER\fR
identifies the
.QW "inner context" ,
which is the innermost atomic command or bytecode instruction that raised the
error, along with its arguments when available. While \fBCALL\fR and \fBUP\fR
provide a trail of the call path, \fBINNER\fR provides details of the offending
operation in the innermost procedure call, even to sub-expression
granularity.
.PP
This information is also present in the \fB\-errorstack\fR entry of the
options dictionary returned by 3-argument \fBcatch\fR; \fBinfo errorstack\fR
is a convenient way of retrieving it for uncaught errors at top-level in an
interactive \fBinterpreter\fR.
.RE
.TP
\fBinfo exists \fIvarName\fR
.
Returns \fB1\fR if a variable named \fIvarName\fR is visible and has been
defined, and \fB0\fR otherwise.
.TP
\fBinfo frame\fR ?\fIdepth\fR?
.
Returns the depth of the call to \fBinfo frame\fR itself.  Otherwise, returns a
dictionary describing the active command at the \fIdepth\fR, which counts all
commands visible to \fBinfo level\fR, plus commands that don't create a new
level, such as \fBeval\fR, \fBsource\fR, or \fIuplevel\fR. The frame depth is
always greater than the current level.
.RS
.PP
If \fIdepth\fR is greater than \fB0\fR it is the frame at that depth.  Otherwise
it is the number of frames up from the current frame.
.PP
As with \fBinfo level\fR and error traces, for nested commands like
.QW "foo [bar [x]]" ,
only
.QW x
is seen by \fBinfo frame\fR invoked within
.QW x .
.PP
The dictionary may contain the following keys:
.TP
\fBtype\fR
.
Always present.  Possible values are \fBsource\fR, \fBproc\fR,
\fBeval\fR, and \fBprecompiled\fR.
.RS
.TP
\fBsource\fR\0\0\0\0\0\0\0\0
.
A script loaded via the \fBsource\fR
command.
.TP
\fBproc\fR\0\0\0\0\0\0\0\0
.
The body of a procedure that could not be traced back to a
line in a particular script.
.TP
\fBeval\fR\0\0\0\0\0\0\0\0
.
The body of a script provided to \fBeval\fR or \fBuplevel\fR.
.TP
\fBprecompiled\fR\0\0\0\0\0\0\0\0
.
A pre-compiled script (loadable by the package
\fBtbcload\fR), and no further information is available.
.RE
.TP
\fBline\fR
.
The line number of of the command inside its script.  Not available for
\fBprecompiled\fR commands.  When the type is \fBsource\fR, the line number is
relative to the beginning of the file, whereas for the last two types it is
relative to the start of the script.
.TP
\fBfile\fR
.
For type \fBsource\fR, provides the normalized path of the file that contains
the command.
.TP
\fBcmd\fR
.
The command before substitutions were performed.
.TP
\fBproc\fR
.
For type \fBprod\fR, the name of the procedure containing the command.
.TP
\fBlambda\fR
.
For a command in a script evaluated as the body of an unnamed routine via the
\fBapply\fR command, the definition of that routine.
.TP
\fBlevel\fR
.
For a frame that corresponds to a level, (to be determined).
.PP
When a command can be traced to its literal definition in some script, e.g.
procedures nested in statically defined procedures, and literal eval scripts in
files or statically defined procedures, its type is \fBsource\fR and its
location is the absolute line number in the script.  Otherwise, its type is
\fBproc\fR and its location is its line number within the body of the
procedure.
.PP
In contrast, procedure definitions and \fBeval\fR within a dynamically
\fBeval\fRuated environment count line numbers relative to the start of
their script, even if they would be able to count relative to the
start of the outer dynamic script. That type of number usually makes
more sense.
.PP
A different way of describing this behaviour is that file-based
locations are tracked as deeply as possible, and where this is not
possible the lines are counted based on the smallest possible
\fBeval\fR or procedure body, as that scope is usually easier to find
than any dynamic outer scope.
.PP
The syntactic form \fB{*}\fR is handled like \fBeval\fR. I.e. if it
is given a literal list argument the system tracks the line number
within the list words as well, and otherwise all line numbers are
counted relative to the start of each word (smallest scope)
.RE
.TP
\fBinfo functions \fR?\fIpattern\fR?
.
If \fIpattern\fR is not given, returns a list of all the math
functions currently defined.
If \fIpattern\fR is given, returns only those names that match
\fIpattern\fR according to \fBstring match\fR.
.TP
\fBinfo globals \fR?\fIpattern\fR?
.
If \fIpattern\fR is not given, returns a list of all the names
of currently-defined global variables.
Global variables are variables in the global namespace.
If \fIpattern\fR is given, only those names matching \fIpattern\fR
are returned.  Matching is determined using the same rules as for
\fBstring match\fR.
.TP
\fBinfo hostname\fR
.
Returns the name of the current host.

This name is not guaranteed to be the fully-qualified domain
name of the host.  Where machines have several different names, as is
common on systems with both TCP/IP (DNS) and NetBIOS-based networking
installed, it is the name that is suitable for TCP/IP networking that
is returned.
.TP
\fBinfo level\fR ?\fIlevel\fR?
.
If \fInumber\fR is not given, the level this routine was called from.
Otherwise returns the complete command active at the given level.  If
\fInumber\fR is greater than \fB0\fR, it is the desired level.  Otherwise, it
is \fInumber\fR levels up from the current level.  A complete command is the
words in the command, with all subsitutions performed, meaning that it is a
list.  See \fBuplevel\fR for more information on levels.
.TP
\fBinfo library\fR
.
Returns the value of \fBtcl_library\fR, which is the name of the library
directory in which the scripts distributed with Tcl scripts are stored.
.TP
\fBinfo loaded \fR?\fIinterp\fR? ?\fIpackage\fR?
.
Returns the name of each file loaded in \fIinterp\fR va \fBload\fR as part of
\fIpackage\fR .  If \fIpackage\fR is not given, returns a list where each item
is the name of the loaded file and the name of the package for which the file
was loaded.  For a statically-loaded package the name of the file is the empty
string.  For \fIinterp\fR, the empty string is the current interpreter.
.TP
\fBinfo locals \fR?\fIpattern\fR?
.
If \fIpattern\fR is given, returns the name of each local variable matching
\fIpattern\fR according to \fBstring match\fR.  Otherwise, returns the name of
each local variable.  A variables defined with the \fBglobal\fR, \fBupvar\fR or
\fBvariable\fR is not local.

.TP
\fBinfo nameofexecutable\fR
.
Returns the absolute pathname of the program for the current interpreter.  If
such a file can not be identified an empty string is returned.
.TP
\fBinfo object\fI subcommand object\fR ?\fIarg ...\fR
.
Returns information about the object named \fIobject\fR. \fIsubcommand\fR is
described \fBOBJECT INTROSPECTION\fR below.
.TP
\fBinfo patchlevel\fR
.
Returns the value of the global variable \fBtcl_patchLevel\fR, in which the
exact version of the Tcl library initially stored.
.TP
\fBinfo procs \fR?\fIpattern\fR?
.
Returns the names of all visible procedures. If \fIpattern\fR is given, returns
only those names that match according to \fBstring match\fR.  Only the final
component in \fIpattern\fR is actually considered a pattern.  Any qualifying
components simply select a namespace.  See \fBNAMESPACE RESOLUTION\fR in the
\fBnamespace\fR(n) documentation.
.TP
\fBinfo script\fR ?\fIfilename\fR?
.
Returns the pathname of the innermost script currently being evaluated, or the
empty string if no pathname can be determined.  If \fIfilename\fR is given,
sets the return value of any future calls to \fBinfo script\fR for the duration
of the innermost active script.  This is useful in virtual file system
applications.
.TP
\fBinfo sharedlibextension\fR
.
Returns the extension used on this platform for names of shared libraries, e.g.
\fB.so\fR under Solaris.  Returns the empty string if shared libraries are not
supported on this platform.
.TP
\fBinfo tclversion\fR
.
Returns the value of the global variable \fBtcl_version\fR, in which the
major and minor version of the Tcl library are stored.
.TP
\fBinfo vars\fR ?\fIpattern\fR?
.
If \fIpattern\fR is not given, returns the names of all visible variables.  If
\fIpattern\fR is given, returns only those names that match according to
\fBstring match\fR.  Only the last component of \fIpattern\fR is a pattern.
Other components identify a namespace.  See \fBNAMESPACE RESOLUTION\fR in the
\fBnamespace\fR(n) documentation.  When \fIpattern\fR is a qualified name,
results are fully qualified.

A variable that has declared but not yet defined is included in the results.
.SS "CLASS INTROSPECTION"
.PP
The following \fIsubcommand\fR values are supported by \fBinfo class\fR:
.TP
\fBinfo class call\fI class method\fR
.
Returns a description of the method implementations that are used to provide a
stereotypical instance of \fIclass\fR's implementation of \fImethod\fR
(stereotypical instances being objects instantiated by a class without having
any object-specific definitions added). This consists of a list of lists of
four elements, where each sublist consists of a word that describes the
general type of method implementation (being one of \fBmethod\fR for an
ordinary method, \fBfilter\fR for an applied filter,
.VS TIP500
\fBprivate\fR for a private method,
.VE TIP500
and \fBunknown\fR for a
method that is invoked as part of unknown method handling), a word giving the
name of the particular method invoked (which is always the same as
\fImethod\fR for the \fBmethod\fR type, and
.QW \fBunknown\fR
for the \fBunknown\fR type), a word giving the fully qualified name of the
class that defined the method, and a word describing the type of method
implementation (see \fBinfo class methodtype\fR).
.RS
.PP
Note that there is no inspection of whether the method implementations
actually use \fBnext\fR to transfer control along the call chain,
.VS TIP500
and the call chains that this command files do not actually contain private
methods.
.VE TIP500
.RE
.TP
\fBinfo class constructor\fI class\fR
.
This subcommand returns a description of the definition of the constructor of
class \fIclass\fR. The definition is described as a two element list; the first
element is the list of arguments to the constructor in a form suitable for
passing to another call to \fBproc\fR or a method definition, and the second
element is the body of the constructor. If no constructor is present, this
returns the empty list.
.TP
\fBinfo class definition\fI class method\fR
.
This subcommand returns a description of the definition of the method named
\fImethod\fR of class \fIclass\fR. The definition is described as a two element
list; the first element is the list of arguments to the method in a form
suitable for passing to another call to \fBproc\fR or a method definition, and
the second element is the body of the method.
.TP
\fBinfo class definitionnamespace\fI class\fR ?\fIkind\fR?
.VS TIP524
This subcommand returns the definition namespace for \fIkind\fR definitions of
the class \fIclass\fR; the definition namespace only affects the instances of
\fIclass\fR, not \fIclass\fR itself. The \fIkind\fR can be either
\fB\-class\fR to return the definition namespace used for \fBoo::define\fR, or
\fB\-instance\fR to return the definition namespace used for
\fBoo::objdefine\fR; the \fB\-class\fR kind is default (though this is only
actually useful on classes that are subclasses of \fBoo::class\fR).
.RS
.PP
If \fIclass\fR does not provide a definition namespace of the given kind,
this command returns the empty string. In those circumstances, the
\fBoo::define\fR and \fBoo::objdefine\fR commands look up which definition
namespace to use using the class inheritance hierarchy.
.RE
.VE TIP524
.TP
\fBinfo class destructor\fI class\fR
.
This subcommand returns the body of the destructor of class \fIclass\fR. If no
destructor is present, this returns the empty string.
.TP
\fBinfo class filters\fI class\fR
.
This subcommand returns the list of filter methods set on the class.
.TP
\fBinfo class forward\fI class method\fR
.
This subcommand returns the argument list for the method forwarding called
\fImethod\fR that is set on the class called \fIclass\fR.
.TP
\fBinfo class instances\fI class\fR ?\fIpattern\fR?
.
This subcommand returns a list of instances of class \fIclass\fR. If the
optional \fIpattern\fR argument is present, it constrains the list of returned
instances to those that match it according to the rules of \fBstring match\fR.
.TP
\fBinfo class methods\fI class\fR ?\fIoptions...\fR?
.
This subcommand returns a list of all public (i.e. exported) methods of the
class called \fIclass\fR. Any of the following \fIoption\fRs may be
given, controlling exactly which method names are returned:
.RS
.TP
\fB\-all\fR
.
If the \fB\-all\fR flag is given,
.VS TIP500
and the \fB\-scope\fR flag is not given,
.VE TIP500
the list of methods will include those
methods defined not just by the class, but also by the class's superclasses
and mixins.
.TP
\fB\-private\fR
.
If the \fB\-private\fR flag is given,
.VS TIP500
and the \fB\-scope\fR flag is not given,
.VE TIP500
the list of methods will also include
the non-exported methods of the class (and superclasses and
mixins, if \fB\-all\fR is also given).
.VS TIP500
Note that this naming is an unfortunate clash with true private methods; this
option name is retained for backward compatibility.
.VE TIP500
.TP
\fB\-scope\fI scope\fR
.VS TIP500
Returns a list of all methods on \fIclass\fR that have the given visibility
\fIscope\fR.  When this option is supplied, both the \fB\-all\fR and
\fB\-private\fR options are ignored. The valid values for \fIscope\fR are:
.RS
.IP \fBpublic\fR 3
Only methods with \fIpublic\fR scope (i.e., callable from anywhere by any instance
of this class) are to be returned.
.IP \fBunexported\fR 3
Only methods with \fIunexported\fR scope (i.e., only callable via \fBmy\fR) are to
be returned.
.IP \fBprivate\fR 3
Only methods with \fIprivate\fR scope (i.e., only callable from within this class's
methods) are to be returned.
.RE
.VE TIP500
.RE
.TP
\fBinfo class methodtype\fI class method\fR
.
This subcommand returns a description of the type of implementation used for
the method named \fImethod\fR of class \fIclass\fR. When the result is
\fBmethod\fR, further information can be discovered with \fBinfo class
definition\fR, and when the result is \fBforward\fR, further information can
be discovered with \fBinfo class forward\fR.
.TP
\fBinfo class mixins\fI class\fR
.
This subcommand returns a list of all classes that have been mixed into the
class named \fIclass\fR.
.TP
\fBinfo class subclasses\fI class\fR ?\fIpattern\fR?
.
This subcommand returns a list of direct subclasses of class \fIclass\fR. If
the optional \fIpattern\fR argument is present, it constrains the list of
returned classes to those that match it according to the rules of
\fBstring match\fR.
.TP
\fBinfo class superclasses\fI class\fR
.
This subcommand returns a list of direct superclasses of class \fIclass\fR in
inheritance precedence order.
.TP
\fBinfo class variables\fI class\fR ?\fB\-private\fR?
.
This subcommand returns a list of all variables that have been declared for
the class named \fIclass\fR (i.e. that are automatically present in the
class's methods, constructor and destructor).
.VS TIP500
If the \fB\-private\fR option is given, this lists the private variables
declared instead.
.VE TIP500
.SS "OBJECT INTROSPECTION"
.PP
The following \fIsubcommand\fR values are supported by \fBinfo object\fR:
.TP
\fBinfo object call\fI object method\fR
.
Returns a description of the method implementations that are used to provide
\fIobject\fR's implementation of \fImethod\fR.  This consists of a list of
lists of four elements, where each sublist consists of a word that describes
the general type of method implementation (being one of \fBmethod\fR for an
ordinary method, \fBfilter\fR for an applied filter,
.VS TIP500
\fBprivate\fR for a private method,
.VE TIP500
and \fBunknown\fR for a
method that is invoked as part of unknown method handling), a word giving the
name of the particular method invoked (which is always the same as
\fImethod\fR for the \fBmethod\fR type, and
.QW \fBunknown\fR
for the \fBunknown\fR type), a word giving what defined the method (the fully
qualified name of the class, or the literal string \fBobject\fR if the method
implementation is on an instance), and a word describing the type of method
implementation (see \fBinfo object methodtype\fR).
.RS
.PP
Note that there is no inspection of whether the method implementations
actually use \fBnext\fR to transfer control along the call chain,
.VS TIP500
and the call chains that this command files do not actually contain private
methods.
.VE TIP500
.RE
.TP
\fBinfo object class\fI object\fR ?\fIclassName\fR?
.
If \fIclassName\fR is not given, this subcommand returns class of the
\fIobject\fR object. If \fIclassName\fR is present, this subcommand returns a
boolean value indicating whether the \fIobject\fR is of that class.
.TP
\fBinfo object creationid\fI object\fR
.VS TIP500
Returns the unique creation identifier for the \fIobject\fR object. This
creation identifier is unique to the object (within a Tcl interpreter) and
cannot be controlled at object creation time or altered afterwards.
.RS
.PP
\fIImplementation note:\fR the creation identifier is used to generate unique
identifiers associated with the object, especially for private variables.
.RE
.VE TIP500
.TP
\fBinfo object definition\fI object method\fR
.
This subcommand returns a description of the definition of the method named
\fImethod\fR of object \fIobject\fR. The definition is described as a two
element list; the first element is the list of arguments to the method in a
form suitable for passing to another call to \fBproc\fR or a method definition,
and the second element is the body of the method.
.TP
\fBinfo object filters\fI object\fR
.
This subcommand returns the list of filter methods set on the object.
.TP
\fBinfo object forward\fI object method\fR
.
This subcommand returns the argument list for the method forwarding called
\fImethod\fR that is set on the object called \fIobject\fR.
.TP
\fBinfo object isa\fI category object\fR ?\fIarg\fR?
.
This subcommand tests whether an object belongs to a particular category,
returning a boolean value that indicates whether the \fIobject\fR argument
meets the criteria for the category. The supported categories are:
.RS
.TP
\fBinfo object isa class\fI object\fR
.
This returns whether \fIobject\fR is a class (i.e. an instance of
\fBoo::class\fR or one of its subclasses).
.TP
\fBinfo object isa metaclass\fI object\fR
.
This returns whether \fIobject\fR is a class that can manufacture classes
(i.e. is \fBoo::class\fR or a subclass of it).
.TP
\fBinfo object isa mixin\fI object class\fR
.
This returns whether \fIclass\fR is directly mixed into \fIobject\fR.
.TP
\fBinfo object isa object\fI object\fR
.
This returns whether \fIobject\fR really is an object.
.TP
\fBinfo object isa typeof\fI object class\fR
.
This returns whether \fIclass\fR is the type of \fIobject\fR (i.e. whether
\fIobject\fR is an instance of \fIclass\fR or one of its subclasses, whether
direct or indirect).
.RE
.TP
\fBinfo object methods\fI object\fR ?\fIoption...\fR?
.
This subcommand returns a list of all public (i.e. exported) methods of the
object called \fIobject\fR. Any of the following \fIoption\fRs may be
given, controlling exactly which method names are returned:
.RS
.TP
\fB\-all\fR
.
If the \fB\-all\fR flag is given,
.VS TIP500
and the \fB\-scope\fR flag is not given,
.VE TIP500
the list of methods will include those
methods defined not just by the object, but also by the object's class and
mixins, plus the superclasses of those classes.
.TP
\fB\-private\fR
.
If the \fB\-private\fR flag is given,
.VS TIP500
and the \fB\-scope\fR flag is not given,
.VE TIP500
the list of methods will also include
the non-exported methods of the object (and classes, if
\fB\-all\fR is also given).
.VS TIP500
Note that this naming is an unfortunate clash with true private methods; this
option name is retained for backward compatibility.
.VE TIP500
.TP
\fB\-scope\fI scope\fR
.VS TIP500
Returns a list of all methods on \fIobject\fR that have the given visibility
\fIscope\fR.  When this option is supplied, both the \fB\-all\fR and
\fB\-private\fR options are ignored. The valid values for \fIscope\fR are:
.RS
.IP \fBpublic\fR 3
Only methods with \fIpublic\fR scope (i.e., callable from anywhere) are to be
returned.
.IP \fBunexported\fR 3
Only methods with \fIunexported\fR scope (i.e., only callable via \fBmy\fR) are to
be returned.
.IP \fBprivate\fR 3
Only methods with \fIprivate\fR scope (i.e., only callable from within this object's
instance methods) are to be returned.
.RE
.VE TIP500
.RE
.TP
\fBinfo object methodtype\fI object method\fR
.
This subcommand returns a description of the type of implementation used for
the method named \fImethod\fR of object \fIobject\fR. When the result is
\fBmethod\fR, further information can be discovered with \fBinfo object
definition\fR, and when the result is \fBforward\fR, further information can
be discovered with \fBinfo object forward\fR.
.TP
\fBinfo object mixins\fI object\fR
.
This subcommand returns a list of all classes that have been mixed into the
object named \fIobject\fR.
.TP
\fBinfo object namespace\fI object\fR
.
This subcommand returns the name of the internal namespace of the object named
\fIobject\fR.
.TP
\fBinfo object variables\fI object\fRR ?\fB\-private\fR?
.
This subcommand returns a list of all variables that have been declared for
the object named \fIobject\fR (i.e. that are automatically present in the
object's methods).
.VS TIP500
If the \fB\-private\fR option is given, this lists the private variables
declared instead.
.VE TIP500
.TP
\fBinfo object vars\fI object\fR ?\fIpattern\fR?
.
This subcommand returns a list of all variables in the private namespace of
the object named \fIobject\fR. If the optional \fIpattern\fR argument is
given, it is a filter (in the syntax of a \fBstring match\fR glob pattern)
that constrains the list of variables returned. Note that this is different
from the list returned by \fBinfo object variables\fR; that can include
variables that are currently unset, whereas this can include variables that
are not automatically included by any of \fIobject\fR's methods (or those of
its class, superclasses or mixins).
.SH EXAMPLES
.PP
This command prints out a procedure suitable for saving in a Tcl
script:
.PP
.CS
proc printProc {procName} {
    set result [list proc $procName]
    set formals {}
    foreach var [\fBinfo args\fR $procName] {
        if {[\fBinfo default\fR $procName $var def]} {
            lappend formals [list $var $def]
        } else {
            # Still need the list-quoting because variable
            # names may properly contain spaces.
            lappend formals [list $var]
        }
    }
    puts [lappend result $formals [\fBinfo body\fR $procName]]
}
.CE
.SS "EXAMPLES WITH OBJECTS"
.PP
Every object necessarily knows what its class is; this information is
trivially extractable through introspection:
.PP
.CS
oo::class create c
c create o
puts [\fBinfo object class\fR o]
                     \fI\(-> prints "::c"\fR
puts [\fBinfo object class\fR c]
                     \fI\(-> prints "::oo::class"\fR
.CE
.PP
The introspection capabilities can be used to discover what class implements a
method and get how it is defined. This procedure illustrates how:
.PP
.CS
proc getDef {obj method} {
    foreach inf [\fBinfo object call\fR $obj $method] {
        lassign $inf calltype name locus methodtype

        # Assume no forwards or filters, and hence no $calltype
        # or $methodtype checks...

        if {$locus eq "object"} {
            return [\fBinfo object definition\fR $obj $name]
        } else {
            return [\fBinfo class definition\fR $locus $name]
        }
    }
    error "no definition for $method"
}
.CE
.PP
This is an alternate way of looking up the definition; it is implemented by
manually scanning the list of methods up the inheritance tree. This code
assumes that only single inheritance is in use, and that there is no complex
use of mixed-in classes (in such cases, using \fBinfo object call\fR as above
is the simplest way of doing this by far):
.PP
.CS
proc getDef {obj method} {
    if {$method in [\fBinfo object methods\fR $obj]} {
        # Assume no forwards
        return [\fBinfo object definition\fR $obj $method]
    }

    set cls [\fBinfo object class\fR $obj]

    while {$method ni [\fBinfo class methods\fR $cls]} {
        # Assume the simple case
        set cls [lindex [\fBinfo class superclass\fR $cls] 0]
        if {$cls eq ""} {
            error "no definition for $method"
        }
    }

    # Assume no forwards
    return [\fBinfo class definition\fR $cls $method]
}
.CE
.SH "SEE ALSO"
global(n), oo::class(n), oo::define(n), oo::object(n), proc(n), self(n),
tcl_library(n), tcl_patchLevel(n), tcl_version(n)
.SH KEYWORDS
command, information, interpreter, introspection, level, namespace,
object, procedure, variable
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