Subj : Math / Operator Overloading
To   : netscape.public.mozilla.jseng
From : Christopher Mason <cmason@cmason.com>
Date : Tue Apr 01 2003 12:08 pm


I have an application which uses Rhino to interpret bits of javascript
code that perform calculations.  This is all fine and good and it
works.  The problem is that numbers in the calculations are stored as
BigDecimals for precision reasons (they involve financial transactions
that often hinge on fractions of pennies).  This means I have to write
ugly javascript like

   a.plus(b.multiply(c))

instead of nice, pretty javascript like

   a + b * c

Java somewhat complicates this by not having any numerical operations
in the Number class.  This is bad because it locks in the choice of
BigDecimal for all time, because no "builtin" numerical types support
the first statement above except for BigDecimal/BigInteger.

I'm wondering how hard it would be for me to extend Rhino to implement
a kind of operator overloading such that javascript statements like

    a + b * c

might be translated into sets of /java/ calls to BigDecimal equivalent
to

    a.plus(b.multiply(c))

Is this even worth trying to pursue or will it be impossibly difficult? 
Can someone point me at source code files where math is implemented in
Rhino?  Am I nuts?  Any other ideas?

-c

.