nanomath/src/generic/utils.js

import {ReturnsAs} from './helpers.js'
import {ResolutionError} from '#core/helpers.js'
import {Passthru, match} from '#core/TypePatterns.js'
import {boolnum} from '#number/helpers.js'

// Most types are real. Have to make sure to redefine on all non-real types
export const isReal = match(Passthru, boolnum(() => true))
export const isZero = match(Passthru, (math, [T]) => {
   if (!T) { // called with no arguments
      throw new ResolutionError('isZero() requires one argument')
   }
   const z = math.zero(T)
   const eq = math.equal.resolve([T, T])
   return ReturnsAs(eq, x => eq(z, x))
})