CODEWITHSUNDEEP
eiffel
Pipo
Pipo

Reputation: 5083

Alias and multiple names for attributes

Defining various names for a same feature seems possible in Eiffel, what for the attributes?

Is it possible to name an attribute like:

background, bk: COLOR
foreground, fg: COLOR

If not why?

Upvotes: 0

Views: 179

Answers (1)

Jocelyn
Jocelyn

Reputation: 703

In Eiffel background, bk: COLOR

is the same as

background: COLOR
bk: COLOR

(same convention for local variables, arguments, ...)

To have a kind of alias on an attribute, you may do

background: COLOR assign set_background
bk: COLOR assign set_background
   do
      Result := background
   end
set_background (c: COLOR)
   do
       background := c
   end

Side note: for function and procedure ... even if it looks an alias

foo, bar: STRING 
  do 
    Result := "abc" 
  end

In fact, bar is not an alias for foo, they are two different features. In descendant, you can rename, redefine one or the other independently.

There is no notion of such alias name in Eiffel. The only concept of alias is used to have operator such as plus alias "+" (s: READABLE_STRING_GENERAL): like Current in class STRING_32 . Or also in HASH_TABLE item alias "[]"

Upvotes: 2

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