Simplify pow function

This commit is contained in:
Laurenz 2023-04-01 23:26:58 +02:00
parent 7ef687ec53
commit e1ecb8cabe
2 changed files with 29 additions and 16 deletions

View File

@ -90,28 +90,24 @@ pub fn pow(
/// The exponent of the power. Must be non-negative. /// The exponent of the power. Must be non-negative.
exponent: Spanned<Num>, exponent: Spanned<Num>,
) -> Value { ) -> Value {
let exponent_value = match exponent.v { let Spanned { v: exp, span } = exponent;
Num::Int(i) if i > u32::MAX as i64 => { match exp {
bail!(exponent.span, "exponent too large"); _ if exp.float() == 0.0 && base.float() == 0.0 => {
bail!(args.span, "zero to the power of zero is undefined")
} }
Num::Int(i) => exponent.v, Num::Int(i) if i32::try_from(i).is_err() => {
Num::Float(f) if f.is_normal() || f == 0 as f64 => exponent.v, bail!(span, "exponent is too large")
_ => {
bail!(
exponent.span,
"exponent must be normal (non-NaN, non-infinite, non-subnormal)"
);
} }
Num::Float(f) if !f.is_normal() && f != 0.0 => {
bail!(span, "exponent may not be NaN, infinite, or subnormal")
}
_ => {}
}; };
if exponent_value.float() == 0 as f64 && base.float() == 0 as f64 { match (base, exp) {
return bail!(exponent.span, "zero to the power of zero is undefined");
}
match (base, exponent_value) {
(Num::Int(a), Num::Int(b)) if b >= 0 => Value::Int(a.pow(b as u32)), (Num::Int(a), Num::Int(b)) if b >= 0 => Value::Int(a.pow(b as u32)),
(a, Num::Int(b)) => Value::Float(a.float().powi(b as i32)), (a, Num::Int(b)) => Value::Float(a.float().powi(b as i32)),
(a, b) => Value::Float(f64::powf(a.float(), b.float())), (a, b) => Value::Float(a.float().powf(b.float())),
} }
} }

View File

@ -76,6 +76,23 @@
#test(calc.max(-3, 11), 11) #test(calc.max(-3, 11), 11)
#test(calc.min("hi"), "hi") #test(calc.min("hi"), "hi")
---
// Test the `calc` function.
#test(calc.pow(10, 0), 1)
#test(calc.pow(2, 4), 16)
---
// Error: 10-16 zero to the power of zero is undefined
#calc.pow(0, 0)
---
// Error: 14-31 exponent is too large
#calc.pow(2, 10000000000000000)
---
// Error: 14-36 exponent may not be NaN, infinite, or subnormal
#calc.pow(2, calc.pow(2.0, 10000.0))
--- ---
// Error: 10-12 expected at least one value // Error: 10-12 expected at least one value
#calc.min() #calc.min()