23 Apr
2004
23 Apr
'04
8:42 a.m.
On Fri, Apr 23, 2004 at 03:32:54AM +0200, Sebastian Sylvan wrote:
First you need to parse the expression into a Haskell data type. For this I would recommend Parsec (see Haskell.org). The Haskell data type would be something like
data Expr = AtomD Double | AtomI Integer | Add Expr Expr | Mul Expr Expr | Sub Expr Expr | ....
There is no need to introduce a datatype - for one parameter functions you can parse text directly to a (Double -> Double) function. Of course if you want to do more things with your functions than just evaluation (like printing, symbolic differentiation), introducing a datatype is a good idea. Best regards, Tom -- .signature: Too many levels of symbolic links