[Home] [By Thread] [By Date] [Recent Entries]


7/8/02 9:50:18 AM, Joe English <jenglish@f...> wrote:

>Static type analysis may be necessary in the presence of overloaded
>operators, but I don't believe overloaded operators themselves are
>a priori necessary.  Perl for example uses '<' for numeric comparisons
>and 'lt' for string comparisons.

And note that the choice of '<' or 'lt' is a choice of comparison metric (numerical order vs 
lexicographic order), not a choice of operand type; it has absolutely nothing to do with how the 
operands are represented as bits.  In Perl, it's possible to treat a value as a number for some 
purposes and as a string for others.  Any "casting" takes place behind the scenes, in the innards of 
the interpreter.  The Perl programmer thinks "compare these two values according to this metric," not 
"cast these values to this type and compare them."  Note that in Perl, strings that don't begin with 
digits are treated as zero for purposes of numeric comparison.




Site Map | Privacy Policy | Terms of Use | Trademarks
Free Stylus Studio XML Training:
W3C Member