Re: A question about certain language features
foo[1..0] is already a legal (null) slice, using it to mean length(foo) will
break existing code. Perhaps a better scheme would be using -1 for the end
of the sequence. This is also fairly intuitive:
foo[1..3] means the first thru third elements conting from the beginning,
and
foo[-3..-1] would mean the third thru first elements counting from the end.
also something like foo[2..-2] would be legal (this would return the
sequence minus the first and last element)
Internally a negative slice would be converted like this:
foo[-3..-1] becomes foo[length(foo)+1-3,length(foo)=1-1] which can be
simplifed in this case to foo[length(foo)-2..length(foo)]
Of course, the same negative indexing should apply to subscripts, where it
is even more intuitive:
foo[4] is the fouth element form the beginning, foo[-4] is the fourth
element from the end.
-- Mike Nelson
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