Comments on: Scala Gets Operator Overloading Right

By: Braden McDorman

Braden McDorman — Wed, 18 Nov 2009 13:04:57 +0000

DannyB: The usage you describe is a little ambiguous.. Is the integer a day, month, or year? I believe a more descriptive name would be in order. Fortunately Scala allows you to use any one parameter functions as operators, so you could easily have “+days”. “Date +days 100″

Thanks,
Braden

By: DannyB

DannyB — Wed, 19 Aug 2009 13:33:39 +0000

It does make sense to override + and – on Date.

Date + integer => Date
Date – integer => Date
Date – Date = integer

By: joeygibson

joeygibson — Mon, 01 Jun 2009 00:15:51 +0000

Anders, my understanding was that if you overloaded math operators in C++, it still respected the regular precedence.

By: Anders

Anders — Sun, 31 May 2009 21:15:58 +0000

…I meant to have an IMO somewhere there, of course. Sorry if I came across as trying to pass off opinion as fact. :(

By: Anders

Anders — Sun, 31 May 2009 21:14:49 +0000

C++ doesn’t do it right; you can’t define new operators, only provide definitions for existing ones.

(Also, I miss user-specified fixity, but that’s mostly just because I can never remember Scala’s builtin precedences :p)

By: Henrik

Henrik — Sun, 31 May 2009 18:49:55 +0000

Hi, you might be interested in the following example:

http://web.archive.org/web/20080204102246/users.utu.fi/hvkhut/scalad/infix.htm

By: Mads Andersen

Mads Andersen — Sun, 31 May 2009 07:03:49 +0000

Uhh, your multiply of complex numbers is wrong ;-)

Remember that i == sqrt(-1). So i*i = -1. Look here: http://en.wikipedia.org/wiki/Complex_numbers#Formal_development