feat: add arithmetic functions for number

src/number/arithmetic.js

@@ -0,0 +1,21 @@
+import {number, plain} from './type'
+
+export const abs = plain(Math.abs)
+export const absquare = plain(a => a*a)
+export const add = plain((a, b) => a + b)
+export const divide = plain((a, b) => a / b)
+export const cbrt = plain(a => {
+   if (a === 0) return a
+   const negate = a < 0 
+   if (negate) a = -a
+   let result = a
+   if (isFinite(a)) {
+      result = Math.exp(Math.log(x) / 3)
+      result = (a / (result * result) + (2 * result)) / 3
+   }
+   return negate ? -result : result
+})
+export const invert = plain(a => 1/a)
+export const multiply = plain((a, b) => a * b)
+export const negate = plain(a => -a)
+export const quotient = plain((a,b) => Math.floor(a/b))

src/number/type.js

@@ -0,0 +1,6 @@
+export const number = {
+   test: n => typeof n === 'number'
+}
+
+export plain = f =>
+   [Array(f.length).fill(number), {returns: number, behavior: f}]