Mosaic matrix: Difference between revisions

=={{header|JavaScript}}==

<lang javascript>(() => {

"use strict";

// ------------------ MOSAIC MATRIX ------------------

// mosaic :: Int -> [[Int]]

const mosaic = n => matrix(n)(n)(

row => col => (1 + row + col) % 2

);

// ---------------------- TEST -----------------------

// main :: IO ()

const main = () =>

// Matrices of dimensions 7 and 8.

[7, 8].map(

compose(

showMatrix(String),

mosaic

)

).join("\n\n");

// --------------------- GENERIC ---------------------

// compose (<<<) :: (b -> c) -> (a -> b) -> a -> c

const compose = (...fs) =>

// A function defined by the right-to-left

// composition of all the functions in fs.

fs.reduce(

(f, g) => x => f(g(x)),

x => x

);

// matrix Int -> Int -> (Int -> Int -> a) -> [[a]]

const matrix = nRows => nCols =>

// A matrix of a given number of columns and rows,

// in which each value is a given function of its

// (zero-based) column and row indices.

f => Array.from({

length: nRows

}, (_, iRow) => Array.from({

length: nCols

}, (__, iCol) => f(iRow)(iCol)));

// showMatrix :: (a -> String) -> [[a]] -> String

const showMatrix = fShow =>

rows => 0 < rows.length ? (() => {

const w = fShow(Math.max(...rows.flat())).length;

return rows.map(

cells => cells.map(

x => fShow(x).padStart(w, " ")

).join(" ")

).join("\n");

})() : "";

// main

return main();

})();</lang>

{{Out}}

<pre>1 0 1 0 1 0 1

0 1 0 1 0 1 0

1 0 1 0 1 0 1

0 1 0 1 0 1 0

1 0 1 0 1 0 1

0 1 0 1 0 1 0

1 0 1 0 1 0 1

1 0 1 0 1 0 1 0

0 1 0 1 0 1 0 1

1 0 1 0 1 0 1 0

0 1 0 1 0 1 0 1

1 0 1 0 1 0 1 0

0 1 0 1 0 1 0 1

1 0 1 0 1 0 1 0

0 1 0 1 0 1 0 1</pre>