Comments on: 3 Ruby Quirks You Have to Love

By: Matt

Matt — Thu, 22 Oct 2009 01:41:25 +0000

I like to use heredoc identifiers nearly consistent with Ruby itself, with a little meta data tacked on:

eval <<-"end;"

def #{name}

# magic

end

end;

Or:

eval <<-"end:accessor"

# same as above

end:accessor

In some text editors, it can make syntax highlighting still work.

By: Sam Rawlins

Sam Rawlins — Sat, 17 Oct 2009 22:28:28 +0000

I like your nested heredocs example. I think we can think of better examples when we consider that heredocs are typically used to generate a string of many, many lines, and if the nested feature is meant for assignment:

article = < #{author=< #{date=< #{content=< Content here. Content content.
More lines and lines.CONTENT
ARTICLE # => "…

This basically is ERB though… embedding ruby code in special symbols (#{} above, <% %> in ERB), and everything outside special symbols is string.

By: enebo

enebo — Fri, 16 Oct 2009 15:35:16 +0000

heh…I am not sure if it is my font size, but that snippet makes my eyes blur a little. :) Single and double quotes right next to each other never look quite right to me. I just tried:

a = %q{"double"} %Q{'single'} expecting the feature to work and it broke!

Still I can see why you are doing it and it is making me think this feature is used a little more than I thought.

By: enebo

enebo — Fri, 16 Oct 2009 15:27:38 +0000

Yeah I knew you could continue lines with backslash and spaced it out when I was writing this. It definitely makes the feature a tiny bit more useful. I am still thinking I like heredocs a bit better in cases for perhaps all but two-line cases?

By: priteau

priteau — Fri, 16 Oct 2009 10:04:15 +0000

It's useful to cleverly concatenate the results of preprocessor macros… but also handy when you want to wrap your code at 80 columns.

By: Geoff

Geoff — Fri, 16 Oct 2009 06:16:02 +0000

I mostly find it useful when mixing single and double quoted strings:



  a= '"double"'   "'single'"

By: jedediah

jedediah — Thu, 15 Oct 2009 22:54:20 +0000

and apparently it breaks intensedebate

pretend there are backslashes after "foo" and "bar"

By: jedediah

jedediah — Thu, 15 Oct 2009 22:53:02 +0000

Backslash continues lines in Ruby:

"foo"

"bar"

"baz"

=> "foobarbaz"

By: djwonk

djwonk — Thu, 15 Oct 2009 22:49:06 +0000

Ah, the joys of default values for method parameters! This reminds me of a nokogiri example:

def at path, ns = document.root ? document.root.namespaces : {}
search(path, ns).first
end

Yeah, you can use the ternary operator as a default value for a parameter. If you want. And you leave out the parenthesis too. Easily readable? Not to me.

By: enebo

enebo — Thu, 15 Oct 2009 22:38:19 +0000

As a reply to your last sentence I am not sure I follow what you are asking? You don't think that everything being an expression allows executable code in class bodies … or you don't see being able to do this as an advantage?