> +Although most rational implementations normalize or "reduce" fractions > +to their smallest representation immediately through a gcd algorithm, > +Perl allows a rational datatype to do so lazily at need, such as > +whenever the denominator would run out of precision, but avoid the > +overhead otherwise. Hence, if you are adding a bunch of C<Rat>s that > +represent, say, dollars and cents, the denominator may stay 100 the > +entire way through. The C<.nu> and C<.de> methods will return these > +unreduced values. You can use C<$rat.=norm> to normalize the fraction. > +The C<.perl> method will produce a decimal number if the denominator is > +a multiple of 10. Otherwise it will normalize and return a rational > +literal of the form -47/3. Stringifying a rational always converts > +to C<Num> and stringifies that, so the rational internal form is > +somewhat hidden from the casual user, who would generally prefer > +to see decimal notation.

Wouldn't it be better to produce a decimal number if the denominator equals of 2**n * 5**m for n,m unsigned int? Before displaying the value should be "decimal-normalized" by multiplying numerator and denominator by 2**|n-m| or 5**|n-m| depending on sign(n-m). Otherwise adding Rats representing dollars and cents which are immediately normalized could produce flapping between rational literal form and decimal number form. Aside from that the specification should be: if the denominator equals 10**n, with n unsigned integer, .perl will produce a decimal number. Otherwise 1/30 would produce a decimal number like 0.0333333..., which was probably not intended. Regards, Ron