[steveklabnik]

"get" is a function that takes a string and a block.

And the block is bound to the uri given in the string, so your guess is correct.

[rbanffy]

Ruby always confuses me with this flexible syntax...

[steveklabnik]

It's possible that you just haven't read enough ruby, then. There are only two variations on the syntax of passing a block to a function, "do/end" and "{ }". By convention, multiline blocks use do/end, and single line blocks use {}.

It's also possible that one of the things in the article is the gotcha, flexible parenthesis. By convention, Rubyists tend to use parenthesis when defining functions, but not when calling them:

    def get(path, opts={}, &block)

    get "/hello" do

not

    get("hello") do

Which would still work, if you preferred. The exception to this is chaining method calls:

    Users.find_all_by_age(23).select {|user| user.first_name == "steve" }

... not that that's an awesome use of ActiveRecord, but whatever.