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let data = [2, 4, 6, 8];
mean(data); // => 5.0

// common way
const mean = function (xs) {
  let n = xs.length;
  return xs.reduce((m, x) => m + x / n, 0);
};

// using ES6 default parameters and IIFE to emulate

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Алгоритм Хаффмана: реализация на «функциональном» JavaScript

И. Ю. Травкин [email protected] Май, 2018

Ввведение

Просто захотелось.

Общая информация

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let raw = `M,0.455,0.365,0.095,0.514,0.2245,0.101,0.15,15
M,0.35,0.265,0.09,0.2255,0.0995,0.0485,0.07,7
...
F,0.53,0.42,0.135,0.677,0.2565,0.1415,0.21,9`;

let parsed = raw.split("\n").map(line => line.split(",").map((v, i) => i > 0 ? parseFloat(v): v == "M" ? 1 : -1));

let X = parsed.map(row => row.slice(0, row.length - 1));
let y = parsed.map(row => row[row.length - 1]);

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// Console API

const print = o => console.log(JSON.stringify(o));

const printm = A => console.log(A.map(row => row.join("\t")).join("\n"));

// Matrix API

//1
const trans = A => A[0].map((_, j) => A.map(row => row[j]));

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//   _______________________________________
//   | let-in в ML        | a la let-in в JS |
//   |--------------------|------------------|
//   |  let               |  ((              |
//   |    val a = 1       |    a = 1,        |
//   |    val b = 2       |    b = 2         |
//   |  in                |  ) =>            |
//   |    a + b           |    a + b         |
//   |  end               |  )();            |
//   |____________________|__________________|

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// Without memoization

const U = f => f(f);
const Z_ = t => (f => f(n => t(t)(f)(n)));
const Z = U(Z_);

// With memoization

const U_mem = f => f(f, {});

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Transcript show: 'Hello, World!'; cr.