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One pitfall that I ran into when trying out Nim for scientific computing is that Nim follows more a computer science convention than mathematics convention for

One pitfall that I ran into when trying out Nim for scientific computing is that Nim follows more a computer science convention than mathematics convention for exponentiation and negation operators. That is in Nim -2^3=(-2)^3 unlike more scientific computing oriented languages where -2^3=-(2^3). To someone like myself who mainly does scientific work this was quite unexpected and it causes a surprising amount of mental overhead to avoid mistakes. I did like Nim quite a bit otherwise, but essentially found that I was missing some important numerical libraries so did not continue using it.

jb1991 5y ago
To be honest, regardless of the behavior of the language, I would be wrapping things in parentheses to make it explicit anyway.
leephillips 5y ago
Although Nim using weird order of operations is unfortunate, your example is not well chosen. Replace the exponent 3 with an even integer and your point will be clear.
- leephillips 5y ago
  Maybe not that weird, although not the most common syntax. In Nim 0 - 2^2 evaluates to -4, while -2^2 evaluates to +4. So in -2, the - is treated as a unary minus and binds tightly to the 2. It would be bad if Nim were doing + or - before ^, or before *. I have a feeling some other languages treat the unary minus the same way, but don’t know of any examples off hand.
  - cycomanic 5y ago
    Yes when I asked a question about this on their gitter channel, people brought up several languages I think bc is one of them for example. I understand the reasoning I still find it extremely unintuitive personally.
tzs 5y ago
I don't think that is a mathematics convention vs computer science convention thing. Most languages, whether aimed at mathematics or computer science, have exponentiation at higher precedence than unary minus. (JavaScript does not, but it also does not allow unary minus directly in front of the base of an exponentiation so you have to add parenthesis no matter which interpretation you want). The main places you find it the other way are spreadsheets and shells. Is there an explanation from the Nim authors as to why they made such an odd choice?
- cycomanic 5y ago
  IIRC the argument is that unitary negation is the operator with the highest presedence and one should be consistent across logical and mathematical operations. I think this is a not a completely unreasonable stance to take (and several other languages take the same), but it is unintuitive for someone who does significant scientific computing.

jb1991 5y ago

To be honest, regardless of the behavior of the language, I would be wrapping things in parentheses to make it explicit anyway.

leephillips 5y ago

Although Nim using weird order of operations is unfortunate, your example is not well chosen. Replace the exponent 3 with an even integer and your point will be clear.

leephillips 5y ago
Maybe not that weird, although not the most common syntax. In Nim 0 - 2^2 evaluates to -4, while -2^2 evaluates to +4. So in -2, the - is treated as a unary minus and binds tightly to the 2. It would be bad if Nim were doing + or - before ^, or before *. I have a feeling some other languages treat the unary minus the same way, but don’t know of any examples off hand.
- cycomanic 5y ago
  Yes when I asked a question about this on their gitter channel, people brought up several languages I think bc is one of them for example. I understand the reasoning I still find it extremely unintuitive personally.

tzs 5y ago

I don't think that is a mathematics convention vs computer science convention thing. Most languages, whether aimed at mathematics or computer science, have exponentiation at higher precedence than unary minus. (JavaScript does not, but it also does not allow unary minus directly in front of the base of an exponentiation so you have to add parenthesis no matter which interpretation you want). The main places you find it the other way are spreadsheets and shells. Is there an explanation from the Nim authors as to why they made such an odd choice?

cycomanic 5y ago
IIRC the argument is that unitary negation is the operator with the highest presedence and one should be consistent across logical and mathematical operations. I think this is a not a completely unreasonable stance to take (and several other languages take the same), but it is unintuitive for someone who does significant scientific computing.