What language defines % as mod and not remainder?
The other (“remainder”) version which takes its sign from the first argument is pretty much worthless in practice. IMO it doesn’t need any name at all. But what it definitely doesn’t need is a shorter and more convenient name than the useful modulo operator. Its ubiquity is a serious screwup in programming language design, albeit largely accidental.
In my opinion neither are used sufficiently often to justify taking up a valuable ASCII symbol (same with xor).
As one simple example, it is frequently useful to map floats into the range [0, 2π), but I have never once wanted to map positive floats into the range [0, 2π) while negative floats get mapped into (–2π, 0] by the same code.
- https://github.com/JuliaLang/julia/issues/14826
mod(-eps(), 4.0)
fld(1.0,0.2)
mod(1.0,0.1)
mod(0.95,0.01)
re: mod 2pi, typically it is most accurate to reduce to (-pi,pi) (i.e. division rounding to nearest). Also to get it accurate you need fancy range reduction algorithms, hence julia has rem2pi https://docs.julialang.org/en/stable/base/math/#Base.Math.re...
These examples don’t really have much bearing on the general usefulness of “remainder” vs. “modulo” though.
I don’t know what is available as chip instructions, I could certainly believe hardware designers made the wrong choice.
[0] http://www.lispworks.com/documentation/lw50/CLHS/Body/f_floo...
[1] http://www.lispworks.com/documentation/lw50/CLHS/Body/f_mod_...