[Haskell-cafe] Begginer question
Maurício
briqueabraque at yahoo.com
Wed Jan 5 20:37:04 EST 2005
Hi,
When compiling this:
************
import Complex;
complex_root :: (Float, Float, Float) -> (Complex Float, Complex Float)
complex_root (a,b,c) = (x1,x2) where {
delta = b * b - 4 * a * c :: Float;
sqr_delta = if delta >= 0 then (sqrt delta) :+ 0 else 0 :+ (sqrt delta)
:: (Complex Float);
x1 = (b + sqr_delta)/(2 * a);
x2 = (b - sqr_delta)/(2 * a);
}
***********
I get this error message:
**********
Couldn't match `Float' against `Complex Float'
Expected type: Float
Inferred type: Complex Float
In the second argument of `(+)', namely `sqr_delta'
In the definition of `x1': x1 = (b + sqr_delta)
***********
Can you help me finding what is wrong? Shouldn't "b" be converted to
Complex Float and be summed to sqr_delta?
Thanks for your help,
Maurício
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