val 0.4.2

An arbitrary precision calculator language
Documentation 
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use super::*;

builtin! {
  Log2 {
    name: "log2",
    arity: BuiltinArity::Exact(1),
    call(payload) {
      let number = payload.arguments[0].number(payload.span)?;

      if number.is_zero() || number.is_negative() {
        return Err(Error::new(
          payload.span,
          "Cannot take logarithm of zero or negative number",
        ));
      }

      Ok(Value::Number(number.log2(payload.config)))
    }
  }
}