I wonder if Ruby has something like implicit block parameters or wildcards as in Scala that can be bound and used in further execution like this:
my_collection.each { puts _ }
or
my_collection.each { puts }
There's something like symbol to proc that invokes some method on each element from collection like: array_of_strings.each &:downcase, but I don't want to execute object's method in a loop, but execute some function with this object as a parameter:
my_collection.each { my_method(_) }
instead of:
my_collection.each { |f| my_method(f) }
Is there any way to do that in Ruby?
You should be able to do it with:
my_collection.each &method(:my_method)
method is a method defined on Object class returning an instance of Method class. Method instance, similarly to symbols, defines to_proc method, so it can be used with unary & operator. This operator takes a proc or any object defining to_proc method and turns it into a block which is then passed to a method. So if you have a method defined like:
def my_method(a,b)
puts "#{b}: #{a}"
end
You can write:
[1,2,3,4].each.with_index &:method(:my_method)
Which will translate to:
[1,2,3,4].each.with_index do |a,b|
puts "#{b}: #{a}"
end