What general tips do you have for golfing in Nim? I'm looking for ideas which can be applied to code-golf problems and which are also at least somewhat specific to Nim (e.g. "remove comments" is not an answer).
Please post one tip per answer.
future module contains two main byte-saving features: lambdas and list comprehensions. Lambdas are extremely useful.
For example, this:
proc f(s:any):any=s&", world!"
can be shortened to this:
import future s=>s&", world!"
which saves a byte. Note, however, that lambdas can't be used outside of a parameter list -- so to test your code, you'll have to do something like this:
import future proc test(f: string -> string) = echo f "Hello" test(s=>s&", world!")
As well, list comprehensions can be used with the
future module. For example, this code prints a seq (
@[...]) of all squares less than 100 divisible by 4:
import future echo lc[x*x|(x<-1..9,x*x mod 4==0),int]
Nim is pretty flexible when it comes to function call syntax. For example, here are some ways to call a function with one argument:
ord(c) ord c c.ord
And ways to call a function with two arguments:
max(a,b) a.max(b) a.max b
Choose the golfiest version that works right for your situation, especially regarding precedence. For example, compare:
abs(n)+2 n.abs+2 (abs n)+2
As opposed to:
abs(n+2) (n+2).abs abs n+2
When working with nonnegative integers, sometimes it's better to use unsigned operators. Specifically, if possible, use
%% instead of