Bug #11059: When saving a hash to YAML or JSON the default value isn't stored

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 2.2.1p85 (2015-02-26 revision 49769) [i686-linux]
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN

I tried to serialize/save a hash to a YAML file, with YAML.dump. My hash has a default value set in. When I read the hash back with YAML.load, the default value is lost, because it wasn1t stored in the YAML file. I experienced the same issue using JSON.

require "yaml"
hash={"a"=>0.3,"b"=>0.7}
hash.default=1.0
File.write("hash.yaml",YAML.dump(hash))
hash2=YAML.load(File.read("hash.yaml"))
puts hash2.default
=> nil

[shishir127 (Shishir Joshi)]

JSON is based on JavaScript and the JavaScript default value for hashes can't be changed. The YAML spec says
These primitives were chosen because they are both powerful and familiar: the sequence corresponds to a Perl array and a Python list, the mapping corresponds to a Perl hash table and a Python dictionary.

Python doesn't have a default value for dictionaries and I don't know Perl. It looks like the default value cannot be converted to YAML or JSON to maintain interoperability with other languages.

[jeremyevans0 (Jeremy Evans)]

• Status changed from Open to Closed