gistfile1.js

/*ELOQUENT JAVASCRIPT*/
// forEach
function forEach(array, action) {
  for (var i = 0; i < array.length; i++)
    action(array[i]);
}

// map
function map(func, array) {
  var result = [];
  forEach(array, function (element) {
    result.push(func(element));
  });
  return result;
}

// reduce
function reduce(combine, base, array) {
  forEach(array, function (element) {
    base = combine(base, element);
  });
  return base;
}


// tag
function tag(name, content, attributes) {
  return {name: name, attributes: attributes, content: content};
}

function link(target, text) {
  return tag("a", [text], {href: target});
}

function htmlDoc(title, bodyContent) {
  return tag("html", [tag("head", [tag("title", [title])]),
                      tag("body", bodyContent)]);
}


// HTML renderer
function escapeHTML(text) {
  var replacements = [[/&/g, "&amp;"], [/"/g, "&quot;"],
                      [/</g, "&lt;"], [/>/g, "&gt;"]];
  forEach(replacements, function(replace) {
    text = text.replace(replace[0], replace[1]);
  });
  return text;
}

function renderAttributes(attributes) {
  if (attributes === null) return "";

  var result = [];
  for (var name in attributes)
    if (attributes.hasOwnProperty(name))
      result.push(" " + name + "=\"" + escapeHTML(attributes[name]) + "\"");
  return result.join("");
}

function renderHTML(element) {
  var pieces = [];

  function render(element) {
    // Text node
    if (typeof element == "string") {
      pieces.push(element);//escapeHTML(element));
    }
    // Empty tag
    else if (!element.content || element.content.length === 0) {
      pieces.push("<" + element.name +
                  renderAttributes(element.attributes) + ">");
    }
    // Tag with content
    else {
      pieces.push("<" + element.name +
                  renderAttributes(element.attributes) + ">");
      forEach(element.content, render);
      pieces.push("</" + element.name + ">");
    }
  }

  render(element);
  return pieces.join("");
}

// op object
var op = {
  "+": function(a, b){return a + b;},
  "==": function(a, b){return a == b;},
  "===": function(a, b){return a === b;},
  "!": function(a){return !a;},
  ">": function(a, b){return a > b;} 
  /* and so on */
};

// partial application
function partial(func) {
  var i;
  var knownArgs = arguments;
  return function() {
    var realArgs = [];
    for (i = 1; i < knownArgs.length; i++)
      realArgs.push(knownArgs[i]);
    for (i = 0; i < arguments.length; i++)
      realArgs.push(arguments[i]);
    return func.apply(null, realArgs);
  };
}

// return new array based on test
function filter(test, array) {
  var result = [];
  forEach(array, function (element) {
  if (test(element))
    result.push(element);
  });
  return result;
}

function any(test, array) {
    for (var i=0; i<array.length; i++) {
        var found = test(array[i]);
        if (found)
            return false;
    }
}

function every(test, array) {
    for (var i=0; i<array.length; i++) {
        var found = test(array[i]);
        if (!found)
            return found;
    }
    return true;
}

function member(array, value) {
    return any(partial(op["==="], value), array);
}