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author | William Joye <wjoye@cfa.harvard.edu> | 2016-10-18 17:31:11 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2016-10-18 17:31:11 (GMT) |
commit | 066971b1e6e77991d9161bb0216a63ba94ea04f9 (patch) | |
tree | 6de02f79b7a4bb08a329581aa67b444fb9001bfd /tcl8.6/doc/object.n | |
parent | ba065c2de121da1c1dfddd0aa587d10e7e150f05 (diff) | |
parent | 9966985d896629eede849a84f18e406d1164a16c (diff) | |
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Merge commit '9966985d896629eede849a84f18e406d1164a16c' as 'tcl8.6'
Diffstat (limited to 'tcl8.6/doc/object.n')
-rw-r--r-- | tcl8.6/doc/object.n | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/tcl8.6/doc/object.n b/tcl8.6/doc/object.n new file mode 100644 index 0000000..df657a9 --- /dev/null +++ b/tcl8.6/doc/object.n @@ -0,0 +1,128 @@ +'\" +'\" Copyright (c) 2007-2008 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 object n 0.1 TclOO "TclOO Commands" +.so man.macros +.BS +'\" Note: do not modify the .SH NAME line immediately below! +.SH NAME +oo::object \- root class of the class hierarchy +.SH SYNOPSIS +.nf +package require TclOO + +\fBoo::object\fI method \fR?\fIarg ...\fR? +.fi +.SH "CLASS HIERARCHY" +.nf +\fBoo::object\fR +.fi +.BE +.SH DESCRIPTION +.PP +The \fBoo::object\fR class is the root class of the object hierarchy; every +object is an instance of this class. Since classes are themselves objects, +they are instances of this class too. Objects are always referred to by their +name, and may be \fBrename\fRd while maintaining their identity. +.PP +Instances of objects may be made with either the \fBcreate\fR or \fBnew\fR +methods of the \fBoo::object\fR object itself, or by invoking those methods on +any of the subclass objects; see \fBoo::class\fR for more details. The +configuration of individual objects (i.e., instance-specific methods, mixed-in +classes, etc.) may be controlled with the \fBoo::objdefine\fR command. +.PP +Each object has a unique namespace associated with it, the instance namespace. +This namespace holds all the instance variables of the object, and will be the +current namespace whenever a method of the object is invoked (including a +method of the class of the object). When the object is destroyed, its instance +namespace is deleted. The instance namespace contains the object's \fBmy\fR +command, which may be used to invoke non-exported methods of the object or to +create a reference to the object for the purpose of invocation which persists +across renamings of the object. +.SS CONSTRUCTOR +The \fBoo::object\fR class does not define an explicit constructor. +.SS DESTRUCTOR +The \fBoo::object\fR class does not define an explicit destructor. +.SS "EXPORTED METHODS" +The \fBoo::object\fR class supports the following exported methods: +.TP +\fIobj \fBdestroy\fR +. +This method destroys the object, \fIobj\fR, that it is invoked upon, invoking +any destructors on the object's class in the process. It is equivalent to +using \fBrename\fR to delete the object command. The result of this method is +always the empty string. +.SS "NON-EXPORTED METHODS" +.PP +The \fBoo::object\fR class supports the following non-exported methods: +.TP +\fIobj \fBeval\fR ?\fIarg ...\fR? +. +This method concatenates the arguments, \fIarg\fR, as if with \fBconcat\fR, +and then evaluates the resulting script in the namespace that is uniquely +associated with \fIobj\fR, returning the result of the evaluation. +.TP +\fIobj \fBunknown ?\fImethodName\fR? ?\fIarg ...\fR? +. +This method is called when an attempt to invoke the method \fImethodName\fR on +object \fIobj\fR fails. The arguments that the user supplied to the method are +given as \fIarg\fR arguments. +.VS +If \fImethodName\fR is absent, the object was invoked with no method name at +all (or any other arguments). +.VE +The default implementation (i.e., the one defined by the \fBoo::object\fR +class) generates a suitable error, detailing what methods the object supports +given whether the object was invoked by its public name or through the +\fBmy\fR command. +.TP +\fIobj \fBvariable \fR?\fIvarName ...\fR? +. +This method arranges for each variable called \fIvarName\fR to be linked from +the object \fIobj\fR's unique namespace into the caller's context. Thus, if it +is invoked from inside a procedure then the namespace variable in the object +is linked to the local variable in the procedure. Each \fIvarName\fR argument +must not have any namespace separators in it. The result is the empty string. +.TP +\fIobj \fBvarname \fIvarName\fR +. +This method returns the globally qualified name of the variable \fIvarName\fR +in the unique namespace for the object \fIobj\fR. +.TP +\fIobj \fB<cloned> \fIsourceObjectName\fR +.VS +This method is used by the \fBoo::object\fR command to copy the state of one +object to another. It is responsible for copying the procedures and variables +of the namespace of the source object (\fIsourceObjectName\fR) to the current +object. It does not copy any other types of commands or any traces on the +variables; that can be added if desired by overriding this method in a +subclass. +.VE +.SH EXAMPLES +.PP +This example demonstrates basic use of an object. +.PP +.CS +set obj [\fBoo::object\fR new] +$obj foo \fI\(-> error "unknown method foo"\fR +oo::objdefine $obj method foo {} { + my \fBvariable\fR count + puts "bar[incr count]" +} +$obj foo \fI\(-> prints "bar1"\fR +$obj foo \fI\(-> prints "bar2"\fR +$obj variable count \fI\(-> error "unknown method variable"\fR +$obj \fBdestroy\fR +$obj foo \fI\(-> error "unknown command obj"\fR +.CE +.SH "SEE ALSO" +my(n), oo::class(n) +.SH KEYWORDS +base class, class, object, root class +.\" Local variables: +.\" mode: nroff +.\" fill-column: 78 +.\" End: |