Hi all,

Does anybody know why was the arithmetic protocol added to strings?

Evaluating '2' > 1 raises a DNU
Evaluating 1 < '2' answers true. Even worse, 1 < '2bla' answers true as well.

This (the successful part) happens because of the implementation mentioned in the subject (plus numeric parser's
behavior). That implementation was not part of the original protocol, as written by Dan Ingalls in 1998.  It seems to
have been added by Yoshiki in 2004. Was this done to address something in particular? To me it seems inconsistent, as in
the above examples. There are other inconsistencies as well: the arithmetic operators mostly work - they were
implemented in String by Yoshiki in 2004 as well, but e.g. 1s + '2' fails ('2' + 1s succeeds). And there is further
funny behavior:

'2' + 1 evaluates to 3
'2' + '1' evaluates to '3'
'2foo' + '1bar' evaluates to '3'


Presumably the failures could be made to work as well, but is this desirable? To me this seems as bad and arbitrary as
Javascript's automatic conversions (there both comparisons mentioned above succeed, but 1 + '2' evaluates to '12' and
'2' + 1 evaluates to '21', whereas 1 - '2' evaluates to -1 and '2' - 1 evaluates to 1. Just beautiful!).

Best,
Florin