redef fun accept_flow_visitor(v)
	do
		self.before_flow_context = v.current_flow_context
		super
		self.after_flow_context = v.current_flow_context
	end

	redef fun accept_flow_visitor(v)
	do
		for e in n_expr do
			if not v.current_flow_context.is_unreachable then
				v.enter_visit(e)
			else if not v.current_flow_context.is_already_unreachable then
				v.current_flow_context.is_already_unreachable = true
				v.toolcontext.error(e.hot_location, "Error: unreachable statement.")
			end
		end
	end

	redef fun accept_flow_visitor(v)
	do
		super
		v.make_unreachable_flow
	end

	redef fun accept_flow_visitor(v)
	do
		var after_expr = v.visit_expr(self.n_expr)

		v.current_flow_context = after_expr.when_true
		v.enter_visit(self.n_then)
		var after_then = v.current_flow_context

		v.current_flow_context = after_expr.when_false
		v.enter_visit(self.n_else)
		var after_else = v.current_flow_context

		v.make_merge_flow(after_then, after_else)
	end

	redef fun accept_flow_visitor(v)
	do
		var after_expr = v.visit_expr(self.n_expr)

		v.current_flow_context = after_expr.when_true
		v.enter_visit(self.n_then)
		var after_then = v.current_flow_context

		v.current_flow_context = after_expr.when_false
		v.enter_visit(self.n_else)
		var after_else = v.current_flow_context

		v.make_merge_flow(after_then, after_else)
	end

	redef fun accept_flow_visitor(v)
	do
		var after_expr = v.visit_expr(self.n_expr)

		v.current_flow_context = after_expr.when_false
		v.enter_visit(n_else)
		# the after context of n_else is a dead end, so we do not care

		v.current_flow_context = after_expr.when_true
	end

	redef fun accept_flow_visitor(v)
	do
		var after_expr = v.visit_expr(self.n_expr)
		v.current_flow_context = after_expr
	end

	redef fun accept_flow_visitor(v)
	do
		var after_expr = v.visit_expr(self.n_expr)
		v.current_flow_context = after_expr
	end

	redef fun accept_flow_visitor(v)
	do
		super
		self.after_flow_context = v.make_sub_flow
	end

	redef fun accept_flow_visitor(v)
	do
		super
		v.make_unreachable_flow
	end

	redef fun accept_flow_visitor(v)
	do
		super
		v.merge_breaks(self.break_mark)
	end

	redef fun accept_flow_visitor(v)
	do
		var after_expr = v.visit_expr(self.n_expr)

		v.make_true_false_flow(after_expr.when_false, after_expr.when_true)
	end

	redef fun accept_flow_visitor(v)
	do
		super
		v.make_sub_true_false_flow
	end

	redef fun accept_flow_visitor(v)
	do
		super
		self.after_flow_context = v.make_sub_flow
	end

	redef fun accept_flow_visitor(v)
	do
		super
	end

	redef fun accept_flow_visitor(v)
	do
		super
		v.make_unreachable_flow
	end

	redef fun accept_flow_visitor(v)
	do
		# FlowContext before the block
		var before_block = v.make_sub_flow

		# Visit the bloc, then merge the breaks
		v.enter_visit(self.n_block)
		v.merge_breaks(self.break_mark)
		var after_block =  v.current_flow_context

		# Visit the catch if there is one
		if self.n_catch != null then
			var before_catch = v.make_sub_flow
			v.make_merge_flow(before_block, after_block)
			v.enter_visit(self.n_catch)
			var after_catch = v.current_flow_context
			v.make_merge_flow(before_catch, after_catch)
		end
	end

	redef fun accept_flow_visitor(v)
	do
		var before_loop = v.make_sub_flow

		var after_expr = v.visit_expr(self.n_expr)

		v.current_flow_context = after_expr.when_true
		v.enter_visit(self.n_block)
		var after_block = v.current_flow_context

		before_loop.add_loop(after_block)
		v.merge_continues_to(before_loop, self.continue_mark)

		v.current_flow_context = after_expr.when_false
		v.merge_breaks(self.break_mark)
	end

	redef fun accept_flow_visitor(v)
	do
		var before_loop = v.make_sub_flow

		v.enter_visit(self.n_block)

		var after_block = v.current_flow_context

		before_loop.add_loop(after_block)
		v.merge_continues_to(before_loop, self.continue_mark)

		v.make_unreachable_flow
		v.merge_breaks(self.break_mark)
	end

	redef fun accept_flow_visitor(v)
	do
		for g in n_groups do
			v.enter_visit(g.n_expr)
		end

		var before_loop = v.make_sub_flow

		v.enter_visit(self.n_block)

		var after_block = v.current_flow_context

		before_loop.add_loop(after_block)
		v.merge_continues_to(before_loop, self.continue_mark)

		v.make_merge_flow(v.current_flow_context, before_loop)
		v.merge_breaks(self.break_mark)
	end

	redef fun accept_flow_visitor(v)
	do
		var after_expr = v.visit_expr(self.n_expr)

		v.current_flow_context = after_expr.when_false
		var after_expr2 = v.visit_expr(self.n_expr2)

		var merge_true = v.make_merge_flow(after_expr.when_true, after_expr2.when_true)
		merge_true.name = "OR TRUE"

		v.make_true_false_flow(merge_true, after_expr2.when_false)
	end

	redef fun accept_flow_visitor(v)
	do
		var after_expr = v.visit_expr(self.n_expr)

		v.current_flow_context = after_expr.when_true
		var after_expr2 = v.visit_expr(self.n_expr2)

		var merge_true = v.make_merge_flow(after_expr.when_false, after_expr2.when_true)
		merge_true.name = "OR TRUE"

		v.make_true_false_flow(merge_true, after_expr2.when_false)
	end

	redef fun accept_flow_visitor(v)
	do
		var after_expr = v.visit_expr(self.n_expr)

		v.current_flow_context = after_expr.when_true
		var after_expr2 = v.visit_expr(self.n_expr2)

		var merge_false = v.make_merge_flow(after_expr.when_false, after_expr2.when_false)
		merge_false.name = "AND FALSE"

		v.make_true_false_flow(after_expr2.when_true, merge_false)
	end

	redef fun accept_flow_visitor(v)
	do
		super
		v.make_sub_true_false_flow
	end

	redef fun accept_flow_visitor(v)
	do
		super
		v.make_sub_true_false_flow
	end