Direct access to bits of mantissa?

[dcnorris]

For a plotting task (where floating-point-style errors are tolerable), I find myself needing injective mappings from rectangular grids $\{0..X\}\times\{0..Y\}\subset\mathbb{N}^2$ into $[0,1]\subset\mathbb{Q}$, such that $(0,0)\mapsto 0$ and $(X,Y)\mapsto 1$. One suitable approach would compose this mapping as the affine map,

$(x,y) \mapsto (\frac{x}{X},\frac{y}{Y})$

with a second mapping $[0,1]^2 \rightarrow [0,1]$ constructed by interleaving [finite prefixes of] the bits of $\frac{x}{X}$ and $\frac{y}{Y}$.

To this end, it would be expedient to have access to the mantissa of a floating point number, as e.g. with SWI's float_parts/4. Obviously, this is something I could implement in Rust; but is there perhaps already a way (even a 'dirty trick') to access these bits in Scryer?

I recognize we have arithmetic:number_to_rational/3, but that seems roundabout and presumably computationally expensive.

[hurufu]

I think it is possible to recover exact bit pattern (if you know size and format) just by using algebraic expressions, but I haven't thought about it much.

[triska]

Please see an issue with related discussion about this: #1343

Maybe format_//2 is enough to get sufficient precision?