Tcl Source Code

I'm not sure whether this is a documentation bug, an implementation one. The documentation states "Filters are not invoked when processing an invocation of the unknown method because of a failure to locate a method implementation, or when invoking either constructors or destructors."

However, the sample below shows filters are called for unknown and for destructors (though apparently not for constructors).

(tcl) 76 % oo::class create C {
method m {} {puts m}
method f {args} {puts f; next {*}$args}
filter f
method unknown {meth args} {puts unknown}
}
::C
(tcl) 77 % C create o
::o
(tcl) 78 % o m
f
m
(tcl) 79 % o n
f
unknown
(tcl) 80 % 
(tcl) 80 % o destroy
f

By the way, [info object call o n] also reflects this.

Corrected the documentation to say that filters are called for unknown method processing. Simpler than changing the current implementation.

And now I've looked again, the filter is <i>not</i> being called for the destructor. It's being called for the <tt>destroy</tt> method, which is a conventional method (that happens to kill the current object).

Filters definitely shouldn't be called in the destructor chain. That would be an outright bug.
<p>
If they're called in the unknown chain, I might leave that in and alter the docs.

Side note: <tt>info object call</tt> uses the identical datastructure to the actual call mechanism; it generates a call chain and introspects it instead of generating it and calling along it. (<tt>self call</tt> looks at the current call chain.) It should be enough to just look at the chain without calling it; it still exercises the same builder code.