JavaScript / Coffeescript : Lightweight Conversion of HTML Entities to ASCII / ASCII 2 HTML

converter.coffee

html2ascii = (asciis) ->
  asciis.map (e, i, a) ->
    String.fromCharCode HTML_ENTITIES.indexOf(e)  if -1 isnt HTML_ENTITIES.indexOf(e)
ascii2html = (asciis) ->
  asciis.map (e, i, a) ->
    String.fromCharCode +e  if HTML_ENTITIES.hasOwnProperty(e)
HTML_ENTITIES = Array(255)
HTML_ENTITIES["34"] = """
HTML_ENTITIES["38"] = "&"
HTML_ENTITIES["39"] = "'"
HTML_ENTITIES["60"] = "<"
HTML_ENTITIES["62"] = ">"
" ,¡¢,£,¤,¥,¦,§,¨,©,ª,«,¬,­,®,¯,°,±,²,³,´,µ,¶,·,¸,¹,º,»,¼,½,¾,¿,À,Á,Â,Ã,Ä,Å,Æ,Ç,È,É,Ê,Ë,Ì,Í,Î,Ï,Ð,Ñ,Ò,Ó,Ô,Õ,Ö,×,Ø,Ù,Ú,Û,Ü,Ý,Þ,ß,à,á,â,ã,ä,å,æ,ç,è,é,ê,ë,ì,í,î,ï,ð,ñ,ò,ó,ô,õ,ö,÷,ø,ù,ú,û,ü,ý,þ,ÿ".split(",").map (e, i, a) ->
  HTML_ENTITIES[160 + i] = e

ascii2html [ 160, 165, 170 ]
html2ascii [ "£", "÷" ]

gistfile1.js

//lsauer.com - lorenz lo sauer 2012
//description: quick conversion from ASCII to HTML-ENTITIES and back in javascript
//entities start at ASCII 160 to 255, and are of the form ^&[#]?[a-zA-Z]{3,20};$
var HTML_ENTITIES = Array(255);
HTML_ENTITIES['34'] = '"';
HTML_ENTITIES['38'] = '&';
HTML_ENTITIES['39'] = ''';
HTML_ENTITIES['60'] = '<';
HTML_ENTITIES['62'] = '>';
//concat and push.apply won't work for some reason?
' ,¡¢,£,¤,¥,¦,§,¨,©,ª,«,¬,­,®,¯,°,±,²,³,\
´,µ,¶,·,¸,¹,º,»,¼,½,¾,¿,À,Á,Â,Ã,Ä,Å,Æ,Ç,\
È,É,Ê,Ë,Ì,Í,Î,Ï,Ð,Ñ,Ò,Ó,Ô,Õ,Ö,×,Ø,Ù,Ú,Û,\
Ü,Ý,Þ,ß,à,á,â,ã,ä,å,æ,ç,è,é,ê,ë,ì,í,î,ï,\
ð,ñ,ò,ó,ô,õ,ö,÷,ø,ù,ú,û,ü,ý,þ,ÿ'
.split(',').map( function(e,i,a){ HTML_ENTITIES[160+i] = e;} )

//e.g. convert from ASCII to 
//pass an array of ascii numbers -> ascii integers to html symbols
function html2ascii(asciis){
	return asciis.map( function(e,i,a){ if (-1 !== HTML_ENTITIES.indexOf(e) ) return String.fromCharCode(HTML_ENTITIES.indexOf(e))} )
}
function ascii2html(asciis){
	return asciis.map( function(e,i,a){ if (HTML_ENTITIES.hasOwnProperty(e)) return String.fromCharCode(+e)} )
}
//example #1
ascii2html([160,165,170])
//>[" ", "¥", "ª"]
//example #2
html2ascii(['£','÷'])
//>["¢", "ö"]