WyvernResolver.addFile("parser", parser);
WyvernResolver.addFile("typer", typer);
TypedAST res = (TypedAST)new Wyvern().parse(new StringReader(user), "test input");
Type result = res.typecheck(Globals.getStandardEnv(), Optional.<Type>empty());
res = new DSLTransformer().transform(res);
Assert.assertEquals("Int", result.toString());
Value out = res.evaluate(Globals.getStandardEnv());
Assert.assertEquals("IntegerConstant(13)", out.toString());
}