#
msgid ""
msgstr ""

msgid "title: Clojure auto curry"
msgstr ""

msgid "date: 2021-04-24"
msgstr ""

msgid "layout: post"
msgstr ""

msgid "lang: en"
msgstr ""

msgid "ref: clojure-auto-curry"
msgstr ""

msgid ""
"A simple macro defined by [Loretta "
"He](http://lorettahe.github.io/clojure/2016/09/22/clojure-auto-curry) to "
"create Clojure functions that are curried on all arguments, relying on "
"Clojure's multi-arity support:"
msgstr ""

msgid ""
"(defmacro defcurry\n"
"  [fname args & body]\n"
"  (let [partials (map (fn [n]\n"
"                        `(~(subvec args 0 n) (partial ~fname ~@(take n args))))\n"
"                      (range 1 (count args)))]\n"
"    `(defn ~fname\n"
"       (~args ~@body)\n"
"       ~@partials)))\n"
msgstr ""

msgid "A naive `add` definition, alongside its usage and macroexpansion:"
msgstr ""

msgid ""
"user=> (defcurry add\n"
"         [a b c d e]\n"
"         (+ 1 2 3 4 5))\n"
"#'user/add\n"
"\n"
"user=> (add 1)\n"
"#object[clojure.core$partial$fn__5857 0x2c708440 \"clojure.core$partial$fn__5857@2c708440\"]\n"
"\n"
"user=> (add 1 2 3 4)\n"
"#object[clojure.core$partial$fn__5863 0xf4c0e4e \"clojure.core$partial$fn__5863@f4c0e4e\"]\n"
"\n"
"user=> ((add 1) 2 3 4 5)\n"
"15\n"
"\n"
"user=> (((add 1) 2 3) 4 5)\n"
"15\n"
"\n"
"user=> (use 'clojure.pprint)\n"
"nil\n"
"\n"
"user=> (pprint\n"
"        (macroexpand\n"
"         '(defcurry add\n"
"            [a b c d e]\n"
"            (+ 1 2 3 4 5))))\n"
"(def\n"
" add\n"
" (clojure.core/fn\n"
"  ([a b c d e] (+ 1 2 3 4 5))\n"
"  ([a] (clojure.core/partial add a))\n"
"  ([a b] (clojure.core/partial add a b))\n"
"  ([a b c] (clojure.core/partial add a b c))\n"
"  ([a b c d] (clojure.core/partial add a b c d))))\n"
"nil\n"
msgstr ""

msgid ""
"This simplistic `defcurry` definition doesn't support optional parameters, "
"multi-arity, `&` rest arguments, docstrings, etc., but it could certainly "
"evolve to do so."
msgstr ""

msgid ""
"I like how `defcurry` is so short, and abdicates the responsability of doing"
" the multi-arity logic to Clojure's built-in multi-arity support. Simple and"
" elegant."
msgstr ""

msgid "Same Clojure as before, now with auto-currying via macros."
msgstr ""

msgid "Comparison with Common Lisp"
msgstr ""

msgid "My attempt at writing an equivalent for Common Lisp gives me:"
msgstr ""

msgid ""
"(defun curry-n (n fn)\n"
"  (if (= 0 n)\n"
"            (funcall fn)\n"
"            (lambda (&rest rest)\n"
"                (curry-n (something n) fn))))\n"
"\n"
"(defun add (a b c d e)\n"
"  (curry-n\n"
"     (length '(a b c d e))\n"
"     (lambda (&rest rest)\n"
"         (apply #'+ rest))))\n"
msgstr ""

msgid ""
"Without built-in multi-arity support, we have to do more work, like tracking"
" the number of arguments consumed so far. That is, without dependending on "
"any library, sticking to ANSI Common Lisp."
msgstr ""

msgid ""
"This also require `funcall`s, since we return a `lambda` that doesn't live "
"in the function namespace."
msgstr ""

msgid ""
"Like the Clojure one, it doesn't support optional parameters, `&rest` rest "
"arguments, docstrings, etc., but it also could evolve to do so."
msgstr ""