Web ECMAScript

Web ECMAScript

This page is for documenting the differences between the ES5 draft and the requirements for ECMAScript implementations in web browsers.

Identifiers

(this is very rough)

Identifiers containing escape sequences are not equivalent to fully unescaped identifiers in the case that, after fully unescaping identifier, it is a ReservedWord. In particular it is possible to create Identifiers that unescape to a reserved word so long as at least one character is fully escaped. Subsequent use of such identifiers must also have at least one character escaped (otherwise the reserved word will be used instead) but it need not be the same character(s) as that originally used to create the identifier.

15.5.4 Properties of the String Prototype Object

Several extra methods are found on String.prototype for wrapping text in HTML elements (these are all generic; the this value need not be a String object):

Algorithm ToHTMLTag(tag_name, content, attribute_name, attribute_value):

1. if attribute_name is undefined return "<" + tag_name + ">" + content + "</" + tag_name + ">"
2. otherwise return "<" + tag_name + " " + attribute_name + "=\"" + attribute_value + "\">" + content + "</" + tag_name + ">"

String.prototype.anchor(name)

1. Let content be ToString(this)
2. Let n be ToString(name)
3. Return ToHTMLTag("a", content, "name", n)

String.prototype.big()

1. Let content be ToString(this)
2. Return ToHTMLTag("big", content)

String.prototype.blink()

1. Let content be ToString(this)
2. Return ToHTMLTag("blink", content)

String.prototype.bold()

1. Let content be ToString(this)
2. Return ToHTMLTag("b", content)

String.prototype.fixed()

1. Let content be ToString(this)
2. Return ToHTMLTag("tt", content)

String.prototype.fontcolor(color)

1. Let content be ToString(this)
2. Let attribute_value be ToString(color)
3. Return ToHTMLTag("font", content, "color", attribute_value)

String.prototype.fontsize(size)

1. Let content be ToString(this)
2. Let attribute_value be ToString(size)
3. Return ToHTMLTag("font", content, "size", attribute_value)

String.prototype.italics()

1. Let content be ToString(this)
2. Return ToHTMLTag("i", content)

String.prototype.link(href)

1. Let content be ToString(this)
2. Let attribute_value be ToString(href)
3. Return ToHTMLTag("a", content, "href", attribute_value)

String.prototype.small()

1. Let content be ToString(this)
2. Return ToHTMLTag("small", content)

String.prototype.strike()

1. Let content be ToString(this)
2. Return ToHTMLTag("strike", content)

String.prototype.sub()

1. Let content be ToString(this)
2. Return ToHTMLTag("sub", content)

String.prototype.sup()

1. Let content be ToString(this)
2. Return ToHTMLTag("sup", content)

Global scope

ES3.1 claims the global scope "this" is the same as the global object, which is not always true in HTML5.

Stuff that needs a home

Enumeration of objects is in insertion order (but host property order compared to user defined property order does not seem to be significant)