Morzés feladat fájlbeolvasása

const fs = require( 'fs' ), rn = '\r\n'
var file = fs.readFileSync( 'morzeabc.txt', 'utf-8' ),
    DeCode = new Map(), betű, morzejel
file.split( rn )
    .splice( 1 )
    .forEach( ξ => {
        [ betű, morzejel ] = ξ.split( '\t' )
        DeCode.set( morzejel, betű )
    })
file = fs.readFileSync( 'morze.txt', 'utf-8' )
console .log(
    file.split( rn )
        .map( ξ => ξ
            .split(';')
            .map( ξ => ξ
                .split( ' '.repeat(7) )
                .map( ξ => ξ
                    .split( ' '.repeat(3) )
                    .map  ( ξ => DeCode.get( ξ ) )
                    .join ( '' )
                )
                .join( ' ' )
            )
            .join(': ')
        )
)