Convert decimal numbers to Two's Complement binary representation.

vhdl-sux.js

const fs = require('fs');

const dec2bin = (dec) => {
  return (dec >>> 0).toString(2);
}


fs.readFile('lab2-x.txt', 'utf8', (err,data) => {
  // split text into numbers
  const a = data.split(' ');
  // split numbers into integer portion and fraction portion
  const splitNumbers = a.map(a => a.split('.'));
  // store max values for W and F
  let maxW = 0, maxF = 0;
  // iterate through each number
  splitNumbers.forEach(number => {
    const integer = number[0];
    const fraction = number[1];
    // get abs value of integer
    const abs = Math.abs(integer);
    // if greater than max, store integer as max integer
    if (abs > maxW) {
      maxW = abs;
    }
    // initialize power as 0
    let pow = 0;
    // if there's a fraction portion
    if (fraction) {
      // parse fraction part of string as fraction number
      let frac2 = parseInt(fraction)/Math.pow(10, fraction.length);
      // run binary fraction converter
      while(frac2 > 0) {
        pow--; // decrement power every time
        // subtract lower powers of 2 (if possible) until we reach 0.
        const subtractor = Math.pow(2,pow);
        if (frac2 >= subtractor) {
          frac2 -= subtractor;
        }
      }
    }

    // if power is lower than before, store as largest # of powers of 2 needed
    if (pow < maxF) {
      maxF = pow;
    }
  });
  // get number of digits for maxW (get log, add 1 for sign)
  // get number of digits for maxF
  console.log(Math.ceil(Math.log2(maxW))+1, Math.abs(maxF));
  const W = Math.ceil(Math.log2(maxW))+1;
  const F = Math.abs(maxF);

  // get binary 
  const bin = a.map(num => {
    const isNegative = num < 0;
    let int = (Math.round(num*Math.pow(2, F)));
    if (!isNegative) {
      return "0".repeat(10-dec2bin(int).length) + dec2bin(int);
    } else {
      return dec2bin(int).substr(31-9,10);
    }
  });

  for (let i = 0; i < 5; i++) {
    console.log(a[i], bin[i]);
  }
});