Converting from ln2 to ln3

Introduction

Although ln3 is the succesor to LrgNum (ln2), programs written using ln2 cannot be directly compiled using ln3.  ln3 was redesigned and rewritten from the ground up.   This offered the oportunity to remove or change those things from ln2 that didn't work well, or were clunky, or just plain ugly. 

Different header files

All of the header files for ln3 are in a subdirectory called lnv3.  The name of the main header file is lnv3.h.  So, in place of:

#include <ln.h>

you would use:

#include <lnv3/lnv3.h>

There is no header equivalent to the ln2 header lnC.h.  In many cases, there is no longer a need for this header.  Some of the functions in this header, however, are no longer available.  Please see the Table of lnC Equivalents for details.

Different type name

The name of the large intereger type in ln3 is ln.  In ln2, it is LargeNumber.   This started because in the early days of ln3, I needed to use both ln2 and ln3 in the same program.  Once this requirement had passed, I simply saw no reason to change the name.

The difference in type names is really not an issue, however.  Creating a typdef will take care of converting most of your code:

#include <lnv3/lnv3.h> typedef ln LargeNumber;

Fewer Methods

The ln class is much leaner than the LargeNumber class.  Many of the methods that were members of the LargeNumber class have been move to nttl.  Others have just been removed, due to lack of interest.  See the method equivalence table for details.

No direct access to the internal representation

In ln2, the user could directly access the digit array (ln_point), the size, and the sign.  This is no longer possible.  The internal representation has been made private.   Access has been given to the same information, however, through a set of accessor functions.  See the ln3 method documentation for details.

Small LargeNumber Statics

The LargeNumber class contained a set of static LargeNumbers pre-initialized with small scalars (the numbers 1 through 11, if I remember right).   I think that the thought here was that it was more efficient (or possibly more convieneint) to use these than to do an int-to-LargeNumber conversion.  Whatever.   They've been removed.  The ln3 operators provide for efficient mixed-type operations.

Others

I'm sure that there are many other conversion issues that I simply cannot remember right now.  Please contact the author with any that you may encounter.