2 files changed, 36 insertions, 18 deletions

diff --git a/src/main.cpp b/src/main.cpp
index 1499285..061ebbb 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -284,6 +284,7 @@ void fractest()
     println("%1").arg( a );

     b = "0.987";

     println("%1 + %2 = %3").arg( a ).arg( b ).arg( a + b );

+    println("%1 - %2 = %3").arg( a ).arg( b ).arg( a - b );

 }

 

 int main( int , char *[] )

diff --git a/src/number.cpp b/src/number.cpp
index 49e8a60..9fd3865 100644
--- a/src/number.cpp
+++ b/src/number.cpp
@@ -332,6 +332,13 @@ Bu::String Number::toString() const
 

 int Number::digit( int iIdx ) const

 {

+    if( iIdx < 0 )

+    {

+        if( iIdx <= -iScale )

+            return 0;

+        else

+            return aFrac[-1-iIdx];

+    }

     if( iIdx >= aInt.getSize() )

         return 0;

     return aInt[iIdx];

@@ -350,21 +357,26 @@ Number Number::add( const Number &rhs, bool bSub ) const
     if( bPositive == (bSub?!rhs.bPositive:rhs.bPositive))

     {

         ret.bPositive = bPositive;

-        for( int j = 0; j < iPlaces || iCarry > 0; j++ )

+        for( int j = 1-iScale; j < iPlaces || iCarry > 0; j++ )

         {

             int iRes = iCarry + digit( j ) + rhs.digit( j );

-//            Bu::println(" Place: %1 + %2 + (%3) = %4").

+//            Bu::println(" [%5] Place: %1 + %2 + (%3) = %4").

 //                arg( digit(j) ).arg( rhs.digit( j ) ).arg( iCarry )

-//                .arg( iRes );

-            if( iRes == 0 )

+//                .arg( iRes ).arg( j );

+            if( j < 0 )

+                ret.aFrac.set( -1-j, (iRes%iRadix) );

+            else

             {

-                iZeros++;

-                continue;

+                if( iRes == 0 )

+                {

+                    iZeros++;

+                    continue;

+                }

+                for(; iZeros > 0; iZeros-- )

+                    ret.aInt.append( 0 );

+                

+                ret.aInt.append( (iRes%iRadix) );

             }

-            for(; iZeros > 0; iZeros-- )

-                ret.aInt.append( 0 );

-            

-            ret.aInt.append( (iRes%iRadix) );

             if( iRes < iRadix )

                 iCarry = 0;

             else

@@ -378,21 +390,26 @@ Number Number::add( const Number &rhs, bool bSub ) const
         ret.bPositive = bPositive;

         int iRes;

         int iComp = (iRadix-1);

-        for( int j = 0; j < iPlaces; j++ )

+        for( int j = 1-iScale; j < iPlaces; j++ )

         {

             iRes = digit( j ) + (iComp-rhs.digit( j )) + iCarry;

 //            Bu::println(" Place: %1 + %2 + (%3) = %4").

 //                arg( digit(j) ).arg( 9-rhs.digit( j ) ).arg( iCarry )

 //                .arg( iRes );

-            if( iRes == 0 )

+            if( j < 0 )

+                ret.aFrac.set( -1-j, (iRes%iRadix) );

+            else

             {

-                iZeros++;

-                continue;

-            }

-            for(; iZeros > 0; iZeros-- )

-                ret.aInt.append( 0 );

+                if( iRes == 0 )

+                {

+                    iZeros++;

+                    continue;

+                }

+                for(; iZeros > 0; iZeros-- )

+                    ret.aInt.append( 0 );

 

-            ret.aInt.append( (iRes%iRadix) );

+                ret.aInt.append( (iRes%iRadix) );

+            }

             if( iRes < iRadix )

                 iCarry = 0;

             else