Returns the raw text read by the lexer

Property definitions

nitc :: literal $ AStringFormExpr :: _raw_text
	# Returns the raw text read by the lexer
	var raw_text: String is lazy do
		var txt = content
		var behead = 1
		var betail = 1
		if txt.chars[0] == txt.chars[1] and txt.length >= 6 then
			behead = 3
			betail = 3
			if txt.chars[0] == delimiter_start and txt.chars[3] == '\n' then behead = 4 # ignore first \n in """
		end
		return txt.substring(behead, txt.length - behead - betail)
	end
src/literal.nit:204,2--215,4