(*  Title:      Pure/ML-Systems/ml_system.ML

     Author:     Makarius

 ML system and platform operations.

 *)

 signature ML_SYSTEM =

 sig

   val name: string

   val is_polyml: bool

   val is_smlnj: bool

   val platform: string

   val platform_is_cygwin: bool

   val share_common_data: unit -> unit

   val save_state: string -> unit

 end;

 structure ML_System: ML_SYSTEM =

 struct

 val SOME name = OS.Process.getEnv "ML_SYSTEM";

 val is_polyml = String.isPrefix "polyml" name;

 val is_smlnj = String.isPrefix "smlnj" name;

 val SOME platform = OS.Process.getEnv "ML_PLATFORM";

 val platform_is_cygwin = String.isSuffix "cygwin" platform;

 fun share_common_data () = ();

 fun save_state _ = raise Fail "Cannot save state -- undefined operation";

 end;