/home/yuki/workspace/automata/lib/helper.rb:89:in `encode': "\xE4" on US-ASCII (Encoding::InvalidByteSequenceError)
from /home/yuki/workspace/automata/lib/helper.rb:89:in `to_json'
from /home/yuki/workspace/automata/lib/helper.rb:89:in `json'
from /home/yuki/workspace/automata/lib/helper.rb:26:in `json_response'
from /home/yuki/workspace/automata/lib/api/browse.rb:120:in `call'
from /home/yuki/workspace/automata/vendor/bundle/ruby/1.9.1/gems/rack-1.6.0/lib/rack/handler/cgi.rb:33:in `serve'
from /home/yuki/workspace/automata/vendor/bundle/ruby/1.9.1/gems/rack-1.6.0/lib/rack/handler/cgi.rb:9:in `run'
from /home/yuki/workspace/automata/public/api/browse.cgi:8:in `<main>'
たぶんvimの出力がutf-8になってないせいだと思うのですが、よくわからない