bug passing all args from macro to function

[kostya]

def bla1(*args1, **args2)
  p args1
  p args2
end

macro bla2(*args1, **args2)
  bla1(*{{args1}}, **{{args2}})
end

bla2(1, a: 1) # => ok
bla2(1, 2) # => Syntax error in expanded macro: bla2:1: for empty hashes use '{} of KeyType => ValueType'
bla2(a: 1) # => Syntax error in expanded macro: bla2:1: for empty hashes use '{} of KeyType => ValueType'

[asterite]

You can splat inside a macro. And in master you can now double splat inside macros. It's still a bit annoying because if args1 is empty there will be a comma at the beginning and it will fail to parse, but it's still possible.

Solution 1:

macro bla2(*args1, **args2)
  {% if args1.empty? %}
    bla1({{**args2}})
  {% else %}
    bla1({{*args1}}, {{**args2}})
  {% end %}
end

Solution 2:

macro bla2(*args1, **args2)
  bla1(
    {% unless args1.empty? %}
      {{*args1}},
    {% end %}
    {{**args2}}
    )
end

We also have an argify method which the same as splatting (*), maybe we can add an argument to it that is a string to append if it's not empty. So...

macro bla2(*args1, **args2)
  bla1({{args1.argify(", ")}} {{**args2}})
end

What do you think? I needed that argify method with an optional trailing comma a couple of times now. We should probably renamed it to splat, though, and have a double_splat method too.

[asterite]

I just added those methods.

To be honest, I'm not super happy with the way macros currently work (or are implemented), though they usually get the work done. Before 1.0 we'll discuss better alternatives to implement them.