testInfer s = let e = fromJust . parseExpr . lexer $ s
              in  evalState (inferType testEnv e) 0
testInfer s = let e = fromJust . parseExpr . lexer $ s
              in  evalState (inferType testEnv e) 0
testInfer s = let e = fromJust . parseExpr . lexer $ s
              in  evalState (inferType testEnv e) 0