NodePattern for numblock "count" element

[dvandersluis]

Consider:

ruby-parse --27 -e "something { _1 }"
(numblock
  (send nil :something) 1
  (lvar :_1))

The count of numbered parameters is returned as a bare integer, which makes it extra resistant to being captured in a node pattern. It's not an int node so int or int_type? don't work, and if I try #is_a?(Integer) I get ArgumentError: wrong number of arguments (given 2, expected 1) for some reason.

Any suggestions?

[dvandersluis]

#integer? works if only using numblocks, but will fail when mixed with regular blocks:

({block numblock} _recv {(args ...) #integer?})
#=> NoMethodError: undefined method `integer?' for ...

[marcandre]

A precise example of what you are trying to achieve would help me.

You can use %Integer as a matcher, since Integer===(val) corresponds to val.is_a?(Integer)

[marcandre]

You can also use is_a?(%Integer)

What is confusing is that Integer or int are both interpreted the same way currently, and are compiled to Integer_type? and int_type?. The former doesn't make much sense...

[dvandersluis]

%Integer worked! Thanks!

This is the matcher, for rubocop#9127

def_node_matcher :symbol_proc?, <<~PATTERN
  ({block numblock}
    ${(send ...) (super ...) zsuper}
    ${(args (arg _)) %Integer}
    (send (lvar _var) $_))
PATTERN

[marcandre]

Good. The question remains: should the % in front of the constant be necessary, and I'd be tempted to say no. OTOH the fact that Const or %Const would be the same is a bit ugly too...

[dvandersluis]

I agree, allowing Const makes sense to me, even if it introduces the small ugliness.