Ruby Custom String Delimiters

Aleph Fell

2014-07-08 02:34

So, as I'm in the process of transitioning to Bitbucket, which will eventually entail a proper website-ish thing, I'll actually be posting some more developer style stuff here.

First subject: Ruby Custom String Delimiters. This is a feature of Ruby which just shouldn't be allowed. Basically, Ruby claims it can substitute an arbitrary symbol for a string delimiter, by prefixing the delimiter with %q or %Q (depending on if you want a double or single quoted string, which are different in Ruby). Also using a symbol which has a matching closing symbol will cause the closing symbol to be the end of the string (e.g. using [ causes ] to end the string).

Got that? Well, here's some counter-intuitive stuff you have to deal with when trying to parse the damn thing, when playing around with IRB and Ruby 1.8:

%q"Hello\n" == "Hello\n" => False (so it's insufficient to look at quotation mark to determine type of string)
%q][] does not end the string
%q][]] is a syntax error
%q£Hello£ quits IRB

I just can't conceive of a circumstance where this feature is actually useful, outside of obfuscated code competitions. I've programmed in a fair few languages, and I've never once thought this would be useful enough that it outweighs making the code harder to read. Even if it's inherited from another language, this is a good example of why I don't like Ruby: too much flexibility in the language can be counterproductive to understanding the language.

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