PrototypeLookupAlgorithm.st
author |
Jan Vrany <jan.vrany@labware.com> |
|
Tue, 01 Jun 2021 20:19:13 +0100 |
branch | jv |
changeset 25424 |
51bd8a6b196f |
parent 13409 |
5353fa4f93f0
|
permissions |
-rw-r--r-- |
Cherry-picked `Context`
cherry-picked Context.st from a6b6dda4caff:
* 4aaf30c174e9: #DOCUMENTATION by cg, Claus Gittinger <cg@exept.de>
* c67311afcc6c: #OTHER by cg, Claus Gittinger <cg@exept.de>
* 883f79e7b2a6: #FEATURE by cg, Claus Gittinger <cg@exept.de>
* 716f3fbb09e9: Don't mark contexts with `CATCHMARK`, Jan Vrany <jan.vrany@fit.cvut.cz>
* cff24fa817b0: #REFACTORING by stefan, Stefan Vogel <sv@exept.de>
* 521f0d837330: #UI_ENHANCEMENT by cg, Claus Gittinger <cg@exept.de>
* bf1118f0fcca: #UI_ENHANCEMENT by cg, Claus Gittinger <cg@exept.de>
* e587cdd22868: #BUGFIX by cg, Claus Gittinger <cg@exept.de>
* fe9f9487a3ed: #DOCUMENTATION by cg, Claus Gittinger <cg@exept.de>
* d5b781899274: #BUGFIX by cg, Claus Gittinger <cg@exept.de>
* 8258751a7465: #FEATURE by cg, Claus Gittinger <cg@exept.de>
* 40173e082cbc: Copyright updates, Jan Vrany <jan.vrany@fit.cvut.cz>
* 6db5c28207d5: #UI_ENHANCEMENT by cg, Claus Gittinger <cg@exept.de>
* 871ea64fd5dc: #FEATURE by cg, Claus Gittinger <cg@exept.de>
* 4b544a108e4e: #DOCUMENTATION by cg, Claus Gittinger <cg@exept.de>
* 9a8d8399e566: #FEATURE by cgexept.de, Claus Gittinger <cg@exept.de>
* 170b00be0103: #BUGFIX by stefan, Stefan Vogel <sv@exept.de>
* a6c73965eae8: #FEATURE by cg, Claus Gittinger <cg@exept.de>
* ce2a0e462ff0: #FEATURE by cg, Claus Gittinger <cg@exept.de>
* 46a260a9ca92: #FEATURE by cg, Claus Gittinger <cg@exept.de>
* 46cab49167fb: #UI_ENHANCEMENT by exept, Claus Gittinger <cg@exept.de>
* 7d52dfd3997d: #DOCUMENTATION by exept, Claus Gittinger <cg@exept.de>
* c52eeea62763: Fix `Context >> argAndVarNames` in cases when debug info is not available, Jan Vrany <jan.vrany@labware.com>
* b5d6963fe4a9: Backed out changeset c52eeea62763, Jan Vrany <jan.vrany@labware.com>
* 6fd3896f8703: #FEATURE by exept, Claus Gittinger <cg@exept.de>
* b530ee616256: #REFACTORING by cg, Claus Gittinger <cg@exept.de>
* ef9b481d7498: #FEATURE by cg, Claus Gittinger <cg@exept.de>
* ea663b72bd51: #UI_ENHANCEMENT by cg, Claus Gittinger <cg@exept.de>
* 6179572a733c: #FEATURE by exept, Claus Gittinger <cg@exept.de>
* 84155b1b6622: #DOCUMENTATION by exept, Claus Gittinger <cg@exept.de>
* 37d06602d856: *** empty log message ***, Claus Gittinger <cg@exept.de>
* f927b9022fea: *** empty log message ***, Claus Gittinger <cg@exept.de>
* 427d3be62d97: #UI_ENHANCEMENT by exept, Claus Gittinger <cg@exept.de>
"{ Package: 'stx:libbasic' }"
Object subclass:#PrototypeLookupAlgorithm
instanceVariableNames:''
classVariableNames:'TheOneAndOnlyInstance'
poolDictionaries:''
category:'Kernel-Extensions'
!
!PrototypeLookupAlgorithm class methodsFor:'documentation'!
documentation
"
this is a dummy lookupAlgorithm class to demonstrate the meta-object-protoocol support.
Create a sumclass of me, redefine the lookupmethod to return a method proper.
If it returns nil, a doesNotUnderstand will be sent, as usual.
This class does nothing real - it duplicates the algorithm as found in the VM.
obsoleted by Lookup
[author:]
cg (cg@CG-PC)
[see also:]
jan Vrany's paper on Smalltalk's Meta-Object-Protocol proposal.
"
!
examples
"
this is only a test for the lookup; when installed as a class's lookupObject,
the lookup will be called from the VM for instances of that class.
|mthd|
mthd := self new
lookupMethodForSelector:#squared
directedTo:nil
for:100
withArguments:nil
from:nil.
mthd valueWithReceiver:100 arguments:#().
"
! !
!PrototypeLookupAlgorithm class methodsFor:'instance creation'!
new
TheOneAndOnlyInstance isNil ifTrue: [
TheOneAndOnlyInstance := super new.
].
^ TheOneAndOnlyInstance
! !
!PrototypeLookupAlgorithm methodsFor:'lookup'!
lookupMethodForSelector:aSelector directedTo:searchClass for:aReceiver withArguments:argArrayOrNil from:sendingContext
"invoked by the VM to ask me for a method to call.
The arguments are: the selector, receiver and arguments,
the class to start the search in (for here-, super and directed sends)
the sending context.
The returned method object will be put into the inline- and polyCache
at the call site; it might therefore be called more than once for the
same receiver-class/selector combination (once for each call site).
If I return nil, a doesNotUnderstand will be invoked."
|cls md method|
cls := searchClass.
cls isNil ifTrue:[ cls := aReceiver class ].
[ cls notNil ] whileTrue:[
md := cls methodDictionary.
method := md at:aSelector ifAbsent:nil.
method notNil ifTrue:[^ method ].
cls := cls superclass.
].
^ nil
! !
!PrototypeLookupAlgorithm class methodsFor:'documentation'!
version_CVS
^ '$Header: /cvs/stx/stx/libbasic/PrototypeLookupAlgorithm.st,v 1.5 2011-06-28 11:58:00 cg Exp $'
! !