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POClojure's (read-line) returns nil; does not prompt
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  1. POClojure's (read-line) returns nil; does not prompt
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    copied!<p>I'm working on my first proper Clojure program--a chess game. I have the following:</p> <pre><code>(defn human-move [board] (board-utils/print-board board) (print "Enter your move, like this: 'E7 E5' ...") (loop [raw-move (terminal-input)] ;;(read-line)] (println "I just received" raw-move) (if (re-matches #"[A-H][1-8]\s[A-H][1-8]" raw-move) (parse-move raw-move) (do (println "Invalid format! There should be a letter, number, space, letter, and final number.") (print "Try again: ") (recur (read-line)))))) </code></pre> <p>Note the place where <code>read-line</code> is commented out and replaced by <code>terminal-input</code>. <code>read-line</code> was giving me a NullPointerException, so for diagnostic purposes:</p> <pre><code>(defn terminal-input [] (println "input") (let [whatnot (read-line)] (println "received" whatnot) whatnot)) </code></pre> <p>Then, when I call <code>human-move</code>.</p> <pre><code>... +---+---+---+---+---+---+---+---+ | P | P | P | P | P | P | P | P | +---+---+---+---+---+---+---+---+ | R | N | B | Q | K | B | N | R | +---+---+---+---+---+---+---+---+ Enter your move, like this: 'E7 E5' ...input received nil I just received nil </code></pre> <p>I never got a chance to type something in as input. Were this Java, I'd start playing little games with the garbage collector (calling <code>Scanner.next()</code>, for instance), but with Clojure I didn't know what to do besides putting the <code>(flush)</code> in there.</p> <p>For what it's worth, this is with SLIME.</p> <hr> <p>I also tried to have <code>terminal-input</code> provide dummy data, and learned that I'm apparently using <code>loop</code>/<code>recur</code> incorrectly. I haven't investigated it super-thoroughly though, since I've been distracted by the <code>read-line</code> issues. <code></code></p> <p><code></code></p> <p>Thanks in advance.</p>
 

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