ADDED   test/num.test
Index: test/num.test
==================================================================
--- test/num.test
+++ test/num.test
@@ -0,0 +1,33 @@
+# 2001 September 15
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this file is testing the sqlite_*_printf() interface.
+#
+# $Id: printf.test,v 1.31 2009/02/01 00:21:10 drh Exp $
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+do_test num-equal-1.1.1 {
+  sqlite4_num_compare 20 20 
+} {equal}
+do_test num-equal-1.1.2 {
+  sqlite4_num_compare 20 2e1
+} {equal}
+do_test num-equal-1.1.3 {
+  sqlite4_num_compare -00034 -3.4e1
+} {equal}
+# Is +0 > -0?
+#do_test num-equal-1.1.4 {
+#  sqlite4_num_compare +0 -0
+#} {equal}
+
+finish_test

Index: test/test_main.c
==================================================================
--- test/test_main.c
+++ test/test_main.c
@@ -4347,10 +4347,102 @@
     return TCL_ERROR;
   }
   sqlite4_test_control(SQLITE4_TESTCTRL_OPTIMIZATIONS, db, mask);
   return TCL_OK;
 }
+
+#define NUM_FORMAT "sign:%d approx:%d e:%d m:%lld"
+
+/* Append a return value representing a sqlite4_num.
+*/
+static void append_num_result( Tcl_Interp *interp, sqlite4_num A ){
+  char buf[100];
+  sprintf( buf, NUM_FORMAT, A.sign, A.approx, A.e, A.m );
+  Tcl_AppendResult(interp, buf, 0);
+}
+
+/* Convert a string either representing a sqlite4_num (listing its fields as
+** returned by append_num_result) or that can be parsed as one. Invalid
+** strings become NaN.
+*/
+static sqlite4_num test_parse_num( char *arg ){
+  sqlite4_num A;
+  int sign, approx, e;
+  if( sscanf( arg, NUM_FORMAT, &sign, &approx, &e, &A.m)==4 ){
+    A.sign = sign;
+    A.approx = approx;
+    A.e = e;
+    return A;
+  } else {
+    return sqlite4_num_from_text(arg, -1, 0);
+  }
+}
+
+/* Convert return values of sqlite4_num to strings that will be readable in
+** the tests.
+*/
+static char *describe_num_comparison( int code ){
+  switch( code ){
+    case 0: return "incomparable";
+    case 1: return "lesser";
+    case 2: return "equal";
+    case 3: return "greater";
+    default: return "error"; 
+  }
+}
+
+/* Compare two numbers A and B. Returns "incomparable", "lesser", "equal",
+** "greater", or "error".
+*/
+static int test_num_compare(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite4_num A, B;
+  int cmp;
+  if( argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+       " NUM NUM\"", 0);
+    return TCL_ERROR;
+  }
+  
+  A = test_parse_num( argv[1] );
+  B = test_parse_num( argv[2] );
+  cmp = sqlite4_num_compare(A, B);
+  Tcl_AppendResult( interp, describe_num_comparison( cmp ), 0);
+  return TCL_OK; 
+}
+
+/* Create a sqlite4_num from a string. The optional second argument specifies
+** how many bytes may be read.
+*/
+static int test_num_from_text(
+  void *NotUsed,
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int argc,              /* Number of arguments */
+  char **argv            /* Text of each argument */
+){
+  sqlite4_num A;
+  int len;
+  if( argc!=2 && argc!=3 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
+      " STRING\" or \"", argv[0], " STRING INTEGER\"", 0);
+    return TCL_ERROR;
+  }
+
+  if( argc==3 ){
+    if ( Tcl_GetInt(interp, argv[2], &len) ) return TCL_ERROR; 
+  }else{
+    len = -1;
+  }
+
+  A = sqlite4_num_from_text( argv[1], len, 0 );
+  append_num_result(interp, A);
+  return TCL_OK;
+}
 
 /*
 ** Register commands with the TCL interpreter.
 */
 int Sqlitetest1_Init(Tcl_Interp *interp){
@@ -4400,11 +4492,13 @@
      { "sqlite_delete_function",        (Tcl_CmdProc*)delete_function       },
      { "sqlite_delete_collation",       (Tcl_CmdProc*)delete_collation      },
      { "sqlite4_get_autocommit",        (Tcl_CmdProc*)get_autocommit        },
      { "sqlite4_stack_used",            (Tcl_CmdProc*)test_stack_used       },
      { "printf",                        (Tcl_CmdProc*)test_printf           },
-     { "sqlite4IoTrace",              (Tcl_CmdProc*)test_io_trace         },
+     { "sqlite4IoTrace",                (Tcl_CmdProc*)test_io_trace         },
+     { "sqlite4_num_compare",           (Tcl_CmdProc*)test_num_compare      }, 
+     { "sqlite4_num_from_text",         (Tcl_CmdProc*)test_num_from_text    }, 
   };
   static struct {
      char *zName;
      Tcl_ObjCmdProc *xProc;
      void *clientData;