I didn't sign in too far, but isn't the first line of code on their landing page a typo?
(define my-language 'English)
Looks like it's missing a closing single quote. I suppose it could be optional.
(define my-language 'English)
Looks like it's missing a closing single quote. I suppose it could be optional.
There are lots of languages with symbols. Some of them even use the same syntax, like Scala (symbol usage in Scala is uncommon, though). However, the most prominent non-Lisp language that uses symbols all the time is probably Ruby.
Because symbols denote variable names in Lisp code, the expression english calls for the value of english.
If we want the value of the expression to be the english symbol object itself, we need (quote english).
Because that is too verbose for a language in which symbolic processing is prime time, there is a shorthand prefix notation for it, 'english.
'ENGLISH is not a symbol, it's actually a shorter notation for the list (QUOTE ENGLISH). But it evaluates to a symbol: ENGLISH