Re: Java and Python have just discovered "record" type finally after 40 years.

[Niklas Holsti <niklas.holsti@tidorum.invalid>]

On 2023-05-14 9:46, J-P. Rosen wrote:
> Le 13/05/2023 à 18:53, Niklas Holsti a écrit :
>>> What about COBOL and LISP?
>>
>>
>> As I understand it (but I don't claim to be expert), the early COBOL 
>> languages could describe the structure of file records, and of 
>> working-storage objects, as nested sequences of components and 
>> sub-records, but each such description defined a _single_ "record" 
>> object, not a "record" data-type that could have many instances. So if 
>> you wanted to have two record objects with the same structure, you had 
>> to duplicate the whole record description.
> AFAIR, COBOL didn't have types, but you could define a variable LIKE 
> another one.


So I also remembered, but (before writing the above) I looked through 
some COBOL syntaxes on the net and could not find LIKE as part of the 
data division syntax.

However, after more searching, I see that at least current Microfocus 
RM-COBOL supports a "SAME AS" definition that has that effect. I don't 
know when that feature was introduced. I did not find it in the current 
IBM COBOL description.

In Microfocus RM-COBOL, the LIKE word can be used as a boolean relation 
that compares the content of a variable to a pattern, like a regexp 
match. I did not find this kind of relation in IBM COBOL.

Another way to clone a COBOL record structure is to put the record 
structure description in a separate source-code file, and COPY that file 
(like C "include") into the declaration of any object that should have 
that structure. But ugh. And it could make a mess of the "level 
numbers", where the RM-COBOL SAME AS definition adjusts those automatically.