fibonacci function first implementation (missing autotest code) #11
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| if x < 1 || x > 45 { | ||
| // less than one is outside the domain of the mathematical function, | ||
| // and more than 45 overflows uint64 and results in infinite recursion | ||
| panic("fib() called with too small or large value!") |
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Panic will crash the program with a huge and ugly stack trace. It's never the best solution. If we want to quit the program with a fatal condition, log.Fatal is the way to go. Here, I think this should return an error that is then "bubbled up" to the caller and displayed to the user.
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| ophandler{"fac", "Calculate factorial of x", 1, func(a []float64) ([]float64, int, error) { | ||
| x := uint64(a[0]) | ||
| if float64(x) != a[0] { |
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Instead of doing this maneuver with uint64 and float to make sure the number is an integer, maybe use if math.Floor(a) != a { ... } like elsewhere in the code. This avoids the confusing type casting.
| return []float64{float64(fact)}, 1, nil | ||
| }}, | ||
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| ophandler{"fib", "Calculate fibonacci of x", 1, func(a []float64) ([]float64, int, error) { |
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Why not design fib() in a way that it can be called directly from the ophandler?
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| ophandler{"fib", "Calculate fibonacci of x", 1, func(a []float64) ([]float64, int, error) { | ||
| x := a[0] | ||
| if x-float64(uint64(x)) != 0 { |
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Maybe use the same math.Floor approach here?
| if x-float64(uint64(x)) != 0 { | ||
| return nil, 1, errors.New("fibonacci requires an integer number") | ||
| } | ||
| if x < 1. { |
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You don't need a dot at the end in Go. if x < 1 works fine :)
| if x < 1. { | ||
| return nil, 1, errors.New("fibonacci requires a positive number") | ||
| } | ||
| if x > 45. { |
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| ophandler{"fib", "Calculate fibonacci of x", 1, func(a []float64) ([]float64, int, error) { | ||
| x := a[0] | ||
| if x-float64(uint64(x)) != 0 { |
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With a bunch of ifs, we can use a switch. It's cleaner. Remember that in Go, a case is not restricted to one variable. You can do:
switch {
case any_condition:
(...)
case any_other_condition:
(...)
}
and so on.
2 participants
For your appreciation. Will update with autotest code later.