Floating-point numbers are formed of a sign (s), significand (m), exponent
(e), and radix (b):
(-1)^s * m * b^e
where 0<=m<b.
Often we want to access the s-m-e values directly, especially the
significand. Notably when doing comparison for approximate equality by
"masking out" the rounding error in the low order bits; or some multiprecise
work. In ES5 this is painful.
The sign, significand, exponent, radix are intrinsic properties of a Number
(like the length of a String) - so how about exposing them as properties of
Number? Say the sign, significand, and exponent could be read-write and the
radix read-only.
Advantages:
1) extracting the significand is easy:
x.signif
2) scaling is easy (scaleB operation):
x.exponent += N
3) the logB operation is easy:
x.exponent
Also programmers could distinguish a binary value from a decimal without
using typeof, using the 'radix' property instead. This might future-proof
against the possible coming of a Decimal type without breaking existing
code. Does it help there?
_______________________________________________
es-discuss mailing list
[email protected]
https://mail.mozilla.org/listinfo/es-discuss
