Question

I have a following YAML file:

---
main-menu:
  - item: Test1
    param: value
  - item: Test2
    param: value
  - notitem: Test3
    param: value

I’m trying to parse all item entries like so:

#Load menu file
menu = YAML.load_file(file)

#Recursive parse function
parse = lambda do |node|
  node.each do |item|
    if !item['item'].nil? then
     .. do something with item ..
    end #end if
  end #end each
end #end parse

#Return the main menu
parse.call(menu['main-menu'])

Which works just fine… Is there an easier way to filter out all entries that aren’t an item using node.each?

Answer 1

Not that I can see. node is an Array of Hash objects, so each needs to be conditionally checked before you can .. do something with item ... You could just clean up the node.each slightly with a next

menu = YAML.load_file(file)

parse = lambda do |node|
  node.each do |item|
    next unless item.include?('item')
    # .. do something with item ..
  end
end

parse.call(menu['main-menu'])

You could alternatively call reject with a block

menu = YAML.load_file(file)

parse = lambda do |node|
  node.reject { |n| !n.include?('item') }.each do |item|
    # .. do something with item ..
  end
end

parse.call(menu['main-menu'])

Though I don’t know that this is really “easier”!