Just a quick point of clarification: is it correct that nim can only do
overloading in terms of parameter types and ignores the return type?
Aka, the following example code would generate a compiler error:
proc by_two(val: int): int =
result = val * 2
proc by_two(val: int): string =
result = $val & " and " & $val
var
x: int = 3
a: int
b: string
a = x.by_two()
b = x.by_two()
echo a
echo b
The compiler error is
Error: ambiguous call; both test2.by_two(val: int)[declared in test2.nim(2,
5)] and test2.by_two(val: int)[declared in test2.nim(5, 5)] match for: (int)
This is something I came across while writing a framework library. Any
suggestions for working around this?
Essentially, with my framework, the programmer inherits an object and overrides
various methods as needed before running the main algorithm. One of the methods
could either return a sequence (faster) or a table (slower but adds
descriptions while running). In my Python version of the library, its the same
procedure. But with strong static typing, it clearly can't work in the same way
in Nim.
One workaround I've come across already is adding the return var to the
parameters:
proc by_two(val: int, dummy: int): int =
result = val * 2
proc by_two(val: int, dummy: string): string =
result = $val & " and " & $val
var
x: int = 3
a: int
b: string
a = x.by_two(a)
b = x.by_two(b)
echo a
echo b
Kind of confusing, but it works. Any suggestions?
Thanks in advance for any help with this!
