(* after type-checking, id must be declared; do not guard lookup *)
T.TEMP (Symbol.look' env id)
| trans_exp env vartypes (A.ConstExp c) = T.CONST(c)
+ | trans_exp env vartypes (A.StringExp s) = T.STRING(Stringref.new s)
| trans_exp env vartypes (A.OpExp(oper, [e1, e2])) =
T.BINOP(trans_oper oper, trans_exp env vartypes e1, trans_exp env vartypes e2)
| trans_exp env vartypes (A.OpExp(oper, [e])) =