Slugify a string, remove whitespace, convert accented letters and some signs

gistfile1.coffee

slugify = (str) ->
	str = str.replace /^\s+|\s+$/g, ''
	str = str.toLowerCase()

	# remove accents, swap ñ for n, etc
	from = "àáäâèéëêìíïîòóöôùúüûñ箩·/_,:;"
	to   = "aaaaeeeeiiiioooouuuuncrc------"

	for i, character of from.split ''
		str = str.replace new RegExp(character, 'g'), to.charAt i

	# trademark sign
	str = str.replace new RegExp('™', 'g'), 'tm'

	# remove invalid chars
	str = str.replace /[^a-z0-9 -]/g, ''

	# collapse whitespace and replace by -
	str = str.replace /\s+/g, '-'

	# collapse dashes
	str = str.replace /-+/g, '-'