We need implement json.parse method

[EugeneDar]

It would be nice to have a method that gets the string and converts it to a json object, or throws an exception if it can't parse.

[EugeneDar]

@yegor256 if you look at other string methods, we cannot write even a small test for this method, because even for a string longer than 6 characters we already catch StackOverFlow.

[EugeneDar]

Does it make sense to implement a method that can only parse such short strings?