[espadrine]

The same goes in Common Lisp, but for very different reasons:

  * (= (+ 0.1 0.2) 0.3)
  T

In Common Lisp, there is a small epsilon used in floating-point equality: single-float-epsilon. When two numbers are within that delta, they are considered equal.

Meanwhile, in Rakudo, 0.1 is a Rat: a rational number where the numerator and denominator are computed.

You can actually get the same underlying behavior in Common Lisp:

  (= (+ 1/10 2/10) 3/10)

Sadly, not many recent languages have defaults as nice as those. Another example is Julia:

  julia> 1//10 + 2//10 == 3//10
  true

IMO, numerical computations should be correct by default, and fast in opt-in.