Re: Vocabulary matter: Component vs Element vs Item

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Fri, 26 Jul 2013 20:42:21 +0200, Yannick Duchêne (Hibou57)  
<yannick_duchene@yahoo.fr> a écrit:

> Would be nice if there were some explanation somewhere, about how the RM  
> choose to assign their signification to Item and Element. Whether the  
> thing is named from the point of view of whom send or whom receive the  
> thing, is probably important too. You hardly follow a convention if you  
> don't understand it :-D

What about this one, which is fortunately compatible with choice made for  
the Ada standard containers:

  * Component, Element and Item, are all constituents of
    some kind of aggregate.
  * A Component is a big Element, an Element is a more
    rudimentary thing than a Component.
  * A component may be made of Elements. An Element is
    not said to be made of Components (there may be rare
    exceptions). An Element may still be made of Elements.
  * An Item is not a kind of thing, but a status.
  * An Item is an Element or Component of particular attention
    or which receive some kind of focus at some or time.
  * The type of an Item is either that of an Element or
    a Component.

It's compatible with:

  * XML wordings
  * wording used to talk about menus and UIs
  * Ada standard containers naming convention
  * UML wording
  * Current and obsolete meaning of Item
  * Close meanings of Element and Component

Above all, this would explain why for Ada containers, an Item argument is  
of an Element_Type: it's an Element, which receive a particular attention  
at some point.

So I was wrong with my idea of defining an Item_Type first and then a  
subtype of it named Element_Type. There is just an Element_Type, whose  
instances may be generically named either Element or Item.



-- 
“Syntactic sugar causes cancer of the semi-colons.” [1]
“Structured Programming supports the law of the excluded muddle.” [1]
[1]: Epigrams on Programming — Alan J. — P. Yale University