[Oberon] Explaining Texts.

[Jörg]

Peter E.



You have a "strange" approach: On one hand you want to understand high level things like concepts and abstractions and on the other hand you go down to low level things like memory used.

In my whole career I was only interested in the nbr of bytes and internal element memory alignment rules when I wrote compilers.

In my point of view, it's not too useful to understand Texts when you know how much memory a Piece occupies. This memory thingy heavily depends on the compiler not on the language and not on the module you want to understand.

BTW: you always can find the nbr of bytes used by a type T by using  size := SYSTEM.SIZE(T);



Before going down to this detail, it is more important to understand this model:

https://en.wikipedia.org/wiki/Model–view–controller



This basic mechanism of separating data from user interface is used by Texts (data model) and TextFrames (user interface).



And you should read this documentation:

https://www.inf.ethz.ch/personal/wirth/ProjectOberon/PO.System.pdf

- Figure 2.2 gives you an view on how the kernel modules are layered.

- Chapter 5 explains Texts and its piece editor in detail.



br

Jörg



Am 26.07.18, 06:44 schrieb "oberon-bounces at lists.inf.ethz.ch im Auftrag von peter at easthope.ca" <oberon-bounces at lists.inf.ethz.ch im Auftrag von peter at easthope.ca>:



    Hi,

    

    For me, one the bigger difficulties in understanding the system is 

    from the multiple layers of abstraction. An intention in 

    https://en.wikibooks.org/wiki/Oberon#Oberon_Text  

    is to encapsulate abstractions concisely together.

     

    Understanding the relationship of an abstraction to something concrete 

    can also help.  Hence the "Memory Occupied" column in the tables.  Is 

    that information helpful or distracting or misleading?

    

    Thanks,                 ... Peter E.

    

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