Re: Classdef embryonic support

[Michael Goffioul]

On Sat, Jan 12, 2013 at 11:34 AM, Ben Abbott <address@hidden> wrote:

On Jan 6, 2013, at 10:35 PM, Michael Goffioul wrote:

> On Tue, Jan 1, 2013 at 8:09 PM, Michael Goffioul <address@hidden> wrote:
> Hi,
>
> Just a heads up to let people know I've spent some time during my christmas holiday to start working again on the classdef branch. I've just pushed some changes to implement initial support for handle-class and value-class semantic. Don't expect too much out of it, but maybe some of you are interested in giving it a try. For instance, I'd be more than happy if someone would write unit tests for the classdef support.
>
> Did anybody have a chance to give it a try? Although far from finished, it's already somehow usable (you can define classes, methods, properties, use inheritance and make superclass calls; it also supports handle and value semantics).
>
> Michael.

The classef branch now builds on MacOS X! :-)

I'm new to classdef, so I borrowed an example from the Mathworks site, made some modifications, and added some tests (see the attached payment.m)

However, I'm not sure how to go about adding tests to the sources.  Perhaps syntax like below be added to the test feature?

%!classdef payment
%!   properties
%!     rate;
%!     term;
%!     principle;
%!   end
%!   methods
%!     function obj = payment (r, t, p)
%!       obj.rate = r;
%!       obj.term = t;
%!       obj.principle = p;
%!     end
%!     function amt = amount (obj)
%!       i = obj.rate / (12 * 100);
%!       amt = (obj.principle * i) / (1 - (1 + i)^(-obj.term));
%!     end
%!   end
%!endclassdef

For now, tests can be added to a classdef m-file, but I don't see how that would be committed.

See how tests are designed for the old-style class in test/classes/.

 

In any event, the current implementation allows methods to be called as obj.method(arg1,arg2, ...), but not as method (obj, arg1, arg2, ...).

Also Matlab has three universal (?) methods, "properties", "methods", "events".

        properties(obj): Returns a column oriented cellstring array of the public properties for the object.
        methods(obj): Returns a column oriented cellstring array of the public methods for the object.
        events(obj): Returns a column oriented cellstring array of the public events for the object.

For example ...

        methods ('char')

Methods for class char:

abs                evalc              isnan              mrdivide           real               sum
all                evalin             issorted           mtimes             regexp             superiorfloat
and                exist              javaArray          ne                 regexpi            times
anonymousFunction  fftw               java_array         newdepfun          regexprep          transpose
any                find               ldivide            nnz                regexptranslate    tril
bsxfun             fix                le                 nonzeros           rem                triu
ceil               floor              linsolve           not                reshape            uminus
colon              full               lt                 nzmax              round              unicode2native
conj               ge                 max                or                 sign               uplus
ctranspose         gt                 min                permute            sort               xlate
diag               hregister          minus              plus               sortrowsc          xor
display            imag               mldivide           power              sparse
eq                 isfinite           mod                prod               sparsfun
eval               isinf              mpower             rdivide            str2func

There is no core function for properties() or events() for Octave, but there is a methods.m function.

methods ('char')
error: [java] java.lang.ClassNotFoundException: char
error: called from:
error:   /Users/bpabbott/Development/mercurial/classdef/sources/scripts/general/methods.m at line 45, column 16

I don't know if there are any serious compatibility concerns, but I thought  I'd mention what I found while tinkering with classdef.

Thanks for giving it a try, Ben. I'm fully aware of the limitations and all these are on my (huge) TODO list. At the moment, what is supported is:

- classdef file parsing

- handle/value class semantic

- class inheritance

- property/method access with dot-notation

- property/method access restriction (public, protected, private, cell array of classes)

- property accessors

- array of objects(not complete, though)

Michael.