[RB] ReEngine design discussion

[Ducasse]

Imagine you have

Object << #Box      
    slots: { #width};

[Ducasse]

And you have the following methods

foo 

    | tmp1 | 
    tmp1 := Box new.
    

foo2 

    | tmp1 |
    x := 15. 
    tmp1 := Box new.
    

Now a probable scenario is that the dev wants to remove the tmp tmp1 and use instead the instance variable already defined here box.

It is clear that renaming the tmp to box will create a shadow and break the program.

• So rename refactoring should forbid
• May be we should offer a transformation.

May be the flow is convert tmp1 to instance variable (note that if another method define a tmp named tmp1,
the transformation of tmp1 into an instance variable with the same name may create a shadow (this has to be checked)

• May be we should have a merge refactoring that can merge two instance variables.