Module: HashRecursiveMerge

Included in:
Hash
Defined in:
lib/herdis/rmerge.rb

Overview

Hash Recursive Merge

Merges a Ruby Hash recursively, Also known as deep merge. Recursive version of Hash#merge and Hash#merge!.

Category

Ruby

Package

Hash

Author

Simone Carletti <[email protected]>

Copyright

2007-2008 The Authors

License

MIT License

Link

www.simonecarletti.com/

Source

gist.github.com/gists/6391/

Instance Method Summary collapse

Instance Method Details

#rmerge(other_hash) ⇒ Object

Recursive version of Hash#merge

Compared with Hash#merge!, this method supports nested hashes. When both hsh and other_hash contains an entry with the same key, it merges and returns the values from both arrays.

Compared with Hash#merge, this method provides a different approch for merging nasted hashes. If the value of a given key is an Hash and both other_hash abd +hsh includes the same key, the value is merged instead replaced with other_hash value.

h1 = {"a" => 100, "b" => 200, "c" => {"c1" => 12, "c2" => 14}}
h2 = {"b" => 254, "c" => 300, "c" => {"c1" => 16, "c3" => 94}}
h1.rmerge(h2)    #=> {"a" => 100, "b" => 254, "c" => {"c1" => 16, "c2" => 14, "c3" => 94}}

Simply using Hash#merge would return

h1.merge(h2)     #=> {"a" => 100, "b" = >254, "c" => {"c1" => 16, "c3" => 94}}



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# File 'lib/herdis/rmerge.rb', line 62

def rmerge(other_hash)
  r = {}
  merge(other_hash)  do |key, oldval, newval| 
    r[key] = oldval.class == self.class ? oldval.rmerge(newval) : newval
  end
end

#rmerge!(other_hash) ⇒ Object

Recursive version of Hash#merge!

Adds the contents of other_hash to hsh, merging entries in hsh with duplicate keys with those from other_hash.

Compared with Hash#merge!, this method supports nested hashes. When both hsh and other_hash contains an entry with the same key, it merges and returns the values from both arrays.

h1 = {"a" => 100, "b" => 200, "c" => {"c1" => 12, "c2" => 14}}
h2 = {"b" => 254, "c" => 300, "c" => {"c1" => 16, "c3" => 94}}
h1.rmerge!(h2)   #=> {"a" => 100, "b" => 254, "c" => {"c1" => 16, "c2" => 14, "c3" => 94}}

Simply using Hash#merge! would return

h1.merge!(h2)    #=> {"a" => 100, "b" = >254, "c" => {"c1" => 16, "c3" => 94}}



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# File 'lib/herdis/rmerge.rb', line 35

def rmerge!(other_hash)
  merge!(other_hash) do |key, oldval, newval| 
      oldval.class == self.class ? oldval.rmerge!(newval) : newval
  end
end