example.js

import { mutate } from './mutate';
import { example as generate } from './generate';
import { crossover } from './crossover';
import { createPopulation } from './population';
import { createMathFitness } from './fitness';
import { createParser } from './parser';
import { evaluate } from './parser';
import { select2 } from './selection';
import { toString } from './utils';
import { createEvolver } from './evolve';

export const numericSolver = definition => {
  const fitness = createMathFitness({
    definition,
    minDataset: -10,
    maxDataset: 10,
    evaluate
  });

  const population = createPopulation({
    depth: 5,
    size: 200,
    fitness,
    generate
  });

  const [bestProgram, bestFitness] = createEvolver({
    mutate: mutate(generate),
    crossover: crossover(20),
    generate: generate,
    population,
    stopWhen: (counter, bestFitness) => counter === 2000 || bestFitness === 0,
    onIteration: (counter, fitness) =>
      console.log(`Iteration ${counter} : ${fitness}`),
    select: select2(50, 20, fitness)
  })();

  return [bestProgram, bestFitness];
};

const [bestProgram] = numericSolver(x => 3 * x * x + 2 * x + 2);
console.log(bestProgram);