When using a format string that substitutes hash values (or using the % operator on a string), instead of using the Hash's default value if a key is not present, it causes a KeyError.
As an end-user, to get around this, my hash needs to know about all the possible keys ahead of time and pre-assign a value to them or handle the KeyError. Logically, I would assume that the sprintf implementation would use the default Hash value.
I wanted to open this issue to see what your collective thoughts were on this since I have a fork running locally that fixes this issue and was wondering if I could send a patch/PR for this.
This issue is reproducible using the following code:
my_hash=Hash.new('world')puts"hello %{location}"%my_hash# expecting "hello world"# "KeyError: key{location} not found"
hm might it be possible that sprintf only uses default value/or default proc if the hash does has default,
but does still raise KeyError if it doesnt?
another idea would be that is does try to use hash[key] function if hash is a non-hash object.
(but that might reduce the calcing speed if not checked right)
hm might it be possible that sprintf only uses default value/or default proc if the hash does has default,
but does still raise KeyError if it doesnt?
another idea would be that is does try to use hash[key] function if hash is a non-hash object.
(but that might reduce the calcing speed if not checked right)
Nobuyoshi Nakada: this was the change I initially made myself but couldn't get it to work properly with hash substitutions. Maybe I did something wrong in my testing, I will attempt to use your changes, thanks! :)
Hans Mackowiak: so raise KeyError is the default is nil? I think that could work, since if you wanted empty strings as a default, you could simply set an empty string as default value. However, logically, since "#{nil}" (nil.to_s as well for that case) works and returns an empty string, the modulus operator version of it should work the same. What do you think?
Also a general question, how would I go about making the Rubyspec tests pass for this particular pull request? Do I open another PR for the tests in Rubyspec? If so, how do I link these two PRs to work together in the Travis CI build acceptance test?
sprintf.c (rb_str_format): respect default value of a hash. no
longer raises KeyError unless the default value of the hash is
nil. [ruby-core:71354] [Bug #11661]
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