Re: Outers, fields and locals

Thomas Leonard <[email protected]> wrote:
> EvalContext holds three arrays:
> 
>     private final Object[] myLocals;
>     private final Object[] myFields;
>     private final Slot[] myOuters;
> 
> What's the difference between these? My current guess is:
> 
> - locals is a new set of bindings created each time you invoke a
> method and includes the local variables and the method's arguments.
> - fields are the values that were in scope when the object was defined
> and which are used in the object and which aren't in safeScope.
> - outers is everything else.

Almost. IIRC, outers are module-level and top-level variables. This
reduces the amount of copying needed to create a closure; if we had
only myLocals and myFields, then myFields would usually be much
larger. The outers arrays can be shared, one per module.

(It's been most of a decade since I dealt with this code; you should
get someone who still knows it better.)

Darius