Macro argument precedence

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1

What would be the correct way to write this macro? My intention is to just wrap some logging statements in a conditional that would not be included when --no-debug is passed to the compiler.

macro debug(args)
  {% if flag?(:debug) %}
    puts {{ args }}
  {% end %}
end

debug "Hello" # => Hello
debug [1,2,3] # => [1, 2, 3]
debug [1,2,3].map { |r| r.to_s }.join(", ") # => Error: 'Array(Int32)#map' is expected to be invoked with a block, but no block was given
debug([1,2,3].map { |r| r.to_s }.join(", ")) # => Error: 'Array(Int32)#map' is expected to be invoked with a block, but no block was given

Is this possibly an error in parsing argument precedence with macros?

Thank you!

2

Macro interpolation always transforms { ... } into do; ...; end, so the solution is to use parentheses for the puts call inside debug

3

You can also invoke the isinstance or typeof to check whether the input is of string type or not. If string type then directly join or else .to_s and then join

4

Is this by design? Or a bug that nobody was interested in fixing?

5

IMO it would be confusing if the same thing can be written in two different ways to affect macro parsing behind the scenes, so this is likely by design

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