[Oberon] Message Objects in Oberon

[eas lab]

J€rg Straube wrote:

]The beauty of Oberon OS is, that you can extend it.
]Eg in Native Oberon there was an extension of the Text files called "folds".
]With folds it was possible to make different versions of the same source code
](eg a Windows or Linux version of Display.Mod or a German and English version
]of the compiler), choose and enable the needed version before compilation.

] (A little bit comparable to C's #ifdef)
]At compile time of TextFrames.Mod this folds extension was not known.
]By using messages and handlers you can e.g. extend Texts and TextFrames
]without touching the binaries of those modules.

That's fantastic, but why do you say "was"? Is it available?

After I'd read our description of "OO" and <handlers> in our NativeOberon
Texts, I didn't have a project to exercise on; so I lapsed back into a
TurboPascal-3/ALGOL mentality. And now when I see apparent OO code of Oberon,
I can't recognise the structure/meaning.

The functional/concatenative/piping style impresses me greatly these days. eg.
Show me the 1st Texts.Mod , but not from V4
-> locate Texts.Mod | grep -v V4| head -1  ==
/mnt/h17/p11v/ETHforum/ALO140417/40417/Texts.Mod

I'd like to analyse/experiment-with Scheme.Mod
but I must first be able to IMMEDIATELY <recognise the structure>, like we
can for PseudoCode.

Chris Burrows wrote:-
]Read the book titled "Object-Oriented Programming in Oberon-2" by Hanspeter
]M€ssenb€ck. You should find the answer to your question there. Chapter 6
]"Dynamic Binding" is particularly relevant.
]
]He is currently the Head of the Institut f€r Systemsoftware at Johannes
]Kepler Universit€t. His book can be download from their website:
]
]http://ssw.jku.at/Research/Books/

Thanks: that looks excellent.

== Chris Glur.