src/Pure/ML-Systems/polyml-old-basis.ML

 Fixes for the old SML basis library (before Poly/ML 4.2.0).
 *)
 
 structure String =
 struct
-  open String;
   fun isSuffix s1 s2 =
     let val n1 = size s1 and n2 = size s2
     in if n1 = n2 then s1 = s2 else n1 <= n2 andalso String.substring (s2, n2 - n1, n1) = s1 end;
+  open String;
 end;
 
 structure Substring =
 struct
   open Substring;

     open IO;
     val mkTextReader = mkReader;
     val mkTextWriter = mkWriter;
   end;
 end;
+
+structure TextIO =
+struct
+  open TextIO;
+  fun inputLine is =
+    let val s = TextIO.inputLine is
+    in if s = "" then NONE else SOME s end;
+end;