[igneous4]

Thanks for the reply, Sam.

To provide some small examples, I often use Perl, and it gives me some syntax that saves me typing, such as:

* `my @other_list = @a_list[3, 1, 4]` to return just those items from a list (item 3, item 1, and item 4)

* `$str =~ s/$foo/BAR/g` to do string replacements (in string $str, replace all ocurrences of contents of variable $foo with "BAR")

* `my $thing = $colored_objects{red}->[2]` to get item 2 in the list of red-colored objects ($colored_objects is a mapping of color names to lists of items of that color)

* `my $error_msg = "Sorry, but $thing1 doesn't work with $thing2."` to interpolate the values of those 2 variables into the string

* `for (reverse(1 .. 10)) { say "Counting down: $_"; }` (counts down from 10 to 1)

I suppose I've always just guessed that operations like those in a Lisp language would require multiple lines and procedure calls, which would become tedious to write after a while. Is that the case?

[SamReidHughes]

Oh, Perl. In some cases, Lisp would certainly be more verbose. It's probably more tedious than Perl for some things. It also depends on which language you use. Scheme is more tedious than Common Lisp, which is sometimes more tedious than Clojure.

Here are the Clojure equivalents, omitting the act of assigning stuff to variables.

    (map #(a-list %) '(3 1 4))

    ; I'm not modifying x in-place because unfortunately Clojure
    ; doesn't like that.  Common Lisp is more imperative.
     (.replaceAll x foo "BAR")

    ((colored-objects :red) 2)

    (str "Sorry, but " thing1 " doesn't work with " thing2 ".")

    (doseq [i (reverse (range 1 11))]
      (println "Counting down: " i))

If you took the first example and assigned it to a variable other-list, it would typically be in a let expression, with a body.

    (let [other-list (map #(a-list %) '(3 1 4))]
      (subsequent statements that use other-list))

[igneous4]

Thanks for those equivalents, Sam! Informative.

That first `(map #...)` is particularly interesting. Looks like you're applying the item lookup operation across the list of indices. Neat.

[SamReidHughes]

The first example could actually have been

    (map a-list [3 1 4])