etymology-cli/stack.js

To get the source of the words from http : //www.etymonline.com/

/**
 *
 * Stack implementation for manipulating string
 *
 */

var stack = '';

isEmpty = function() {
  return stack == '';
}

pop = function() {
  var c = top();
  stack = stack.slice(0, -1);
  return c;
}

top = function() {
  return stack.slice(-1);
}

push = function(c) {
  stack += c;
}

getpair = function(c) {
  if ((c == ')' && top() == '(') || (c == ']' && top() == '[') || (c == top() && c == '\"')) {
    pop();
    return c;
  } else if (c == '[' || c == '(' || c == '\"') {
    push(c);
  }
  if (!isEmpty()) {
    return top();
  }
  return '';
}