Module: Tins::HashDFS

Extended by:
ThreadLocal
Defined in:
lib/tins/hash_dfs.rb

Overview

HashDFS for a depth‑first traversal for Ruby hash and array structures.

Provides methods to traverse hash structures in a depth-first manner, visiting all keys and values.

Instance Method Summary collapse

Methods included from ThreadLocal

instance_thread_local, thread_local

Instance Method Details

#dfs(visit_internal: false) {|index, object| ... } ⇒ self

Performs a depth‑first search on the receiver’s structure.

Examples:

Basic usage

{ a: 1, b: [2, 3] }.dfs do |idx, val|
  puts "#{idx.inspect} => #{val.inspect}"
end

Parameters:

  • visit_internal (Boolean) (defaults to: false) —

    whether to yield internal hashes/arrays. When false (default) the block is called only for leaf values. When true, the block is called for every node, including the intermediate hashes/arrays that contain other objects.

Yields:

  • (index, object) —

    yields the index/key (or array index) and the object being visited.

Yield Parameters:

  • index (Object, Integer, nil) —

    the key or array index, or nil for the root object.

  • object (Object) —

    the current object (Hash, Array, or leaf).

Returns:

  • (self) —

    returns the receiver for chaining.

Raises:

  • (ArgumentError) —

    if no block is given.



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# File 'lib/tins/hash_dfs.rb', line 32

def dfs(visit_internal: false, &block)
  block or raise ArgumentError, 'require &block argument'
  self.dfs_seen = {}
  stack = []
  stack.push([nil, self])

  while (index, object = stack.pop)
    case
    when dfs_seen[object.__id__]
      next
    when Hash === object
      dfs_seen[object.__id__] = true
      object.each do |k, v|
        stack.push([k, dfs_convert_to_hash_or_ary(v)])
      end
      visit_internal or next
    when Array === object
      dfs_seen[object.__id__] = true
      object.each_with_index do |v, i|
        stack.push([i, dfs_convert_to_hash_or_ary(v)])
      end
      visit_internal or next
    end
    block.(index, object)
  end
  self
ensure
  self.dfs_seen = nil
end

#dfs_convert_to_hash_or_ary(object) ⇒ Hash, ...

Converts the given object into a hash or array if possible.

Examples:

dfs_convert_to_hash_or_ary(Struct.new(:a).new(1)) # => { a: 1 }

Parameters:

  • object (Object) —

    the object to convert.

Returns:

  • (Hash, Array, Object) —

    the converted object or the original object if no conversion method is available.



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# File 'lib/tins/hash_dfs.rb', line 70

def dfs_convert_to_hash_or_ary(object)
  case
  when object.respond_to?(:to_hash)
    object.to_hash
  when object.respond_to?(:to_ary)
    object.to_ary
  else
    object
  end
end