I think you've nailed it pretty well. The only thing I would do is replacemap withmapv everywhere (simpler to avoid lazy lists). Also, as a big believer in TDD, I've added how I would throw in some unit tests to include "live" documentation of what/how each fn works.

(ns tst.demo.core  (:use demo.core tupelo.core tupelo.test)  (:require    [tupelo.string :as str]))

I start off using myfavorite template project and library.

(defn parse-coloring [coloring]  (let [tokens (clojure.string/split coloring #" ")        color  (second tokens)        value  (Integer/parseInt (first tokens))]    {:color color :value value}))(verify  (is= (parse-coloring "1 green")    {:color "green" :value 1}))

So we see the pattern of a unit test for each small function, so a new reader sees sample input/output.

(defn parse-draw [draw]  (let [colorings (clojure.string/split draw #", ")]    (map parse-coloring colorings)))(verify  (is= (parse-draw "1 green, 1 blue, 1 red")    [{:color "green" :value 1}     {:color "blue" :value 1}     {:color "red" :value 1}]))

Same for this function...

(defn parse-game [line]  (let [matches (re-matches #"^Game (\d+): (.*)$" line)        game-id (Integer/parseInt (nth matches 1))        game    (nth matches 2)        draws   (clojure.string/split game #"; ")]    {:id game-id :draws (map parse-draw draws)}))(verify  (is= (parse-game "Game 1: 1 green, 1 blue, 1 red; 11 red, 3 blue")    {:id    1     :draws [[{:color "green" :value 1}              {:color "blue" :value 1}              {:color "red" :value 1}]             [{:color "red" :value 11}              {:color "blue" :value 3}]]}))

and this one. We're almost done.

(defn separate-games  [text]  (mapv str/trim (str/split-lines (str/trim text))))(defn parse-input  [text]  (let [game-strs    (separate-games text)        games-parsed (mapv parse-game game-strs)]    games-parsed))

I broke this up into 2 functions to make unit testing easier.

(verify  (let [; throw in some gratuitous leading/trailing newlines to check robustness        input         "            Game 1: 1 green, 1 blue, 1 red; 11 red, 3 blue            Game 2: 9 green, 9 blue, 1 red; 11 red, 3 blue; 1 blue, 18 red    "        game-strs     (separate-games input)        strs-expected ["Game 1: 1 green, 1 blue, 1 red; 11 red, 3 blue"                       "Game 2: 9 green, 9 blue, 1 red; 11 red, 3 blue; 1 blue, 18 red"]]    (is= game-strs strs-expected)

So we can verify the line-by-line parsing independently of the other processing.

Now, we verify the whole kit-n-kaboodle for a 2 line file.

    (let [games-parsed (parse-input input)]      (is= games-parsed        [{:draws          [[{:color "green", :value 1}            {:color "blue", :value 1}            {:color "red", :value 1}]           [{:color "red", :value 11} {:color "blue", :value 3}]],          :id 1}         {:draws          [[{:color "green", :value 9}            {:color "blue", :value 9}            {:color "red", :value 1}]           [{:color "red", :value 11} {:color "blue", :value 3}]           [{:color "blue", :value 1} {:color "red", :value 18}]],          :id 2}]))))

• clojure