ProgTutorial/Base.thy
changeset 328 c0cae24b9d46
parent 317 d69214e47ef9
child 346 0fea8b7a14a1
equal deleted inserted replaced
327:ce754ad78bc9 328:c0cae24b9d46
    15 (* re-definition of various ML antiquotations    *)
    15 (* re-definition of various ML antiquotations    *)
    16 (* to have a special tag for text enclosed in ML *)
    16 (* to have a special tag for text enclosed in ML *)
    17 
    17 
    18 ML {*
    18 ML {*
    19 (* FIXME ref *)
    19 (* FIXME ref *)
    20 val file_name = ref (NONE : string option)
    20 val file_name = Unsynchronized.ref (NONE : string option)
    21 
    21 
    22 fun write_file txt =
    22 fun write_file txt =
    23   case !file_name of
    23   case !file_name of
    24     NONE => () (* error "No open file" *)
    24     NONE => () (* error "No open file" *)
    25   | SOME name => 
    25   | SOME name =>