I had a need the other day for dealing with some really big
numbers.  Unfortunately, the machine I was using did not have
[mpexpr] installed.  Woe is me.  Until I came up with the following
fast and very dirty workaround.  Works on Unix systems and Windows
systems with Cygwin:

 proc mpexpr { args } {
  return [ exec echo $args | bc -l ]
 }

 % mpexpr 12342342354564636*94852304570297207525
 1170699616126044020647089347918085900

Is it a cheat?  Well, yeah, it's a cheat.  But it was darn handy!

[CMcC] I've written [bignum], a quick critcl wrapper for libgmp, giving arbitrary precision ints and floats.


[Sarnold] I have written a little library for multiple precision arithmetics, in pure Tcl : see [MPA].
It should be cross-platform, although I have tested it only on Windows with ActiveTcl.

[DKF]: Time to learn a bit more [exec] magic:
  proc mpexpr args {
     exec bc -l <<[join $args]
  }

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[Category Mathematics]