src/Pure/ML-Systems/polyml_old_basis.ML

+(*  Title:      Pure/ML-Systems/polyml_old_basis.ML
+    ID:         $Id$
+
+Fixes for the old SML basis library (before Poly/ML 4.2.0).
+*)
+
+structure String =
+struct
+  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;
+  fun isSubstring s1 s2 =
+    String.isPrefix s1 s2 orelse
+      size s1 < size s2 andalso isSubstring s1 (String.extract (s2, 1, NONE)); 
+  open String;
+end;
+
+structure Substring =
+struct
+  open Substring;
+  val full = all;
+end;
+
+structure Posix =
+struct
+  open Posix;
+  structure IO =
+  struct
+    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;