text: 'use strict';
  
  const fs = require('fs');
  const [ src, dest ] = ['src', 'dest'].map(param(process.argv, arg => { throw new Error(`No ${arg} specified!`); }));
  
  fs.readFile(src, 'utf8', function(err, src) {
    if (err) throw err;
    fs.writeFile(dest, format(src), function(err) {
      if (err) throw err;
    });
  });
  
  function format(data) {
    return data
      .replace(/forall/g, '∀')
      .replace(/\->/g, '→')
      .replace(/<\-/g, '←')
      .replace(/=>/g, '⇒')
      .replace(/<=/g, '⇐')
      .replace(/::/g, '∷');
  }
  
  function param(args, onError) {
    return function(name) {
      const arg = `--${name}`;
      const index = args.indexOf(arg);
  
      if (index === -1) {
        return onError(arg);
      }
  
      const val = args[index+1];
  
      if (!val) {
        return onError(arg);
      }
  
      return val;
    }
  }
  