YPS: YAML Positioning System

Taichi Ishitani — Wed, 08 Oct 2025 12:55:18 +0000

It is hard to debug big YAML files because parsed objects do not have their position info; we have to search where are wrong values in the original YAML by eye.

I'm developing a Gem named YPS: YAML Positioning System.
https://github.com/taichi-ishitani/yps

YPS is a Gem to parse YAML and add position info to parsed objects. Parsed objects have the accessor named #position that returns their position info.
You can use this method to get position info in the original YAML of the receiver object.
Here is an example.

require 'yps'

yaml = YPS.load(<<~'YAML')
children:
  - name: kanta
    age: 8
  - name: kaede
    age: 3
YAML

# output
# name: kanta (filename: unknown line 2 column 11)
# age: 8 (filename: unknown line 3 column 10)
# name: kaede (filename: unknown line 4 column 11)
# age: 3 (filename: unknown line 5 column 10)
yaml['children'].each do |child|
  child.each do |key, value|
    puts "#{key}: #{value} (#{value.position})"
  end
end

For more details, please visit its repository and API doc.

Forem: Taichi Ishitani

YPS: YAML Positioning System