Use BCD for calculations about epsilon

[Ecco]

This is indeed a good suggestion.

Currently Poincaré performs all its computations using IEEE754 floating point numbers. We aimed for consistency first, because there are quite a few cases (trigonometry for example) where it would need to use floating-point anyway.

That being said, we could definitely (and should) add an exact math engine.

[Zezombye]

You don't need to use floating point for anything, Casio does trigonometry with BCD. Sure, floating point is faster, but BCD is fast enough for calculations (now, if you do something that requires real-time input like a game, you'd need to use floating point, but calculations require exact math and should always use BCD).

Edit: you probably meant that, because trigonometry can't (AFAIK) give an exact decimal result, that using floating point is enough. In this case I agree, but you'd need to convert to BCD (and still use an exact math, so that sin(45) prints sqrt(2)/2 instead of 0.707).

[Ecco]

Indeed, but this issue is in fact a duplicate of #99.