[Oorexx-devel] Ad comparators in 3.2.0 ...

[Rony G. F. <Ron...@wu...>]

Hi there,

while looking at the possibilities that sort allows for I stumbled over
a few observations which I think are omissions. Not being sure I rather
list them here, but would enter them as bugs (please note that at the
moment I cannot create ooRexx, hence I do not want to check in anything
that I cannot test):

    * "CaselessColumnComparator", "ColumnComparator" and
      "InvertingComparator" should mixinclass "Comparator" instead of
      "Object",

    * the "Descending*Comparator" classes *could* be removed, as using
      "InvertingComparator" would allow for that; if you want to keep
      them (perhaps making it easier for the programmers to sort
      descendingly), then I would suggest that
      "DescendingCaselessComparator" is mixinclassing
      "DescendingComparator" (to match "CaselessComparator" which
      mixinclasses "Comparator"),

    * in the "*ColumnComparator" I noticed that the "length" argument is
      mandatory: shouldn't that remain optional, in which case the
      remainder of the string is taken for comparison purposes? Also,
      while at it, how about enhancing it such that multiple columns
      could/can be compared?

So this would probably mean that:

    * class "ColumnComparator":
          o method "compare" */is missing/*
          o should mixinclass "Comparator"
    * class "CaselessColumnComparator":
          o should mixinclass "Comparator"
    * class "InvertingComparator":
          o in method "compare": "*/USE STRICT ARG left, right/*"  */is
            missing/*
          o should mixinclass "Comparator"

To be able to fully use the classification tree for classifying
purposes, the classes "Comparator" and "DescendingComparator" should
both have either the same parent, or "DescendingComparator" should
specialize "Comparator" or both classes should be marked with a class
that indicates "comparator" functionality. (An alternative could be to
use a package concept, where one would be able to classify by putting
classes belonging together into the same package; but then one would
need an ability to check whether a class got defined to belong to a
certain package.)

Regards,

---rony