[Gcl-devel] MERGE

[Paul F. Dietz]

> 
All of these are fixed by the make-sequence patch I just uploaded,
>  except the last, which I don't understand.
> 
> (merge 'null (list 1 2 3) (list 4 5 6) #'<)
>  
> Why should this be an error?  'null is a subtype of 'list, and as the

The standard also says:

 An error of type type-error should be signaled if result-type
 specifies the number of elements and the sum of the lengths
 of sequence-1 and sequence-2 is different from that number. 

NULL specifies the number of elements (zero).

Now, if you take 'specifies' to mean 'constrains', then
the compound CONS types should also be checked:

  (merge '(cons * (cons * *)) ...) ==> error if the result
     has fewer than two elements

This is getting into some seriously baroque language lawyering,
so don't put a high priority on this.

        Paul