# A modified lexer that feed tokens before and after the real tokens.
class InjectedLexer
	super Lexer

	# The tokens to use before the real tokens (in order).
	var injected_before = new List[Token]

	# The tokens to use after the real tokens (in order).
	# The real EOF token is produced after these tokens.
	var injected_after = new List[Token]
	private var is_finished = false

	redef fun get_token
	do
		if not injected_before.is_empty then
			var tok = injected_before.shift
			return tok
		end
		if not is_finished then
			var next = super
			if not next isa EOF then return next
			injected_after.push(next)
			is_finished = true
		end

		var tok = injected_after.shift
		return tok
	end
end