Hello, PJS (Parrot JavaScript) allows a number to be NaN. The result of comparing an NaN to any value is false (thus all of NaN == NaN, NaN < NaN, NaN > NaN, NaN <= NaN, NaN >= NaN evaluate to false).
There is only the vtable function C<cmp> that a PMC can implement to define ordering. Parrot assumes that for any PMC that wants ordering, each two values of that PMC are ==, < or >, which is not the case for NaNs. Would it not be better if there were different vtable functions for <, <=, > and >= (which can call the C<cmp> vtable function as default)? And here is another issue I encountered with my workaround for my previous problem. Ok, Parrot does not want me to generate an NaN by doing 0.0/0.0, but that does not prevent me from storing NaNs in them (which come from PjsNumber PMCs). But when $N0 is NaN, comparing $N0 <= $N0 gives inconsistent results. For the default runcore, it evaluates to 0 (which is the expected result), but for the jitted core, it evaluates to 1. Is is my fault to store NaNs in N registers, or can I assume that this is a JIT bug? Thanks in advance. Mehmet Soyturk
