Basic command-line arguments parser for Pixie

cli.pxi

#!/usr/bin/env pxi

(ns cli
  "pxi cli.pxi --verbose --bar 42 --hello 'world!'
  {:verbose true, :bar 42, :hello world!}"
  (:require [pixie.string :as string]))

(defn- arg?
  "Returns true if the string is an argument to an option"
  [s]
  (and s (not (string/starts-with? s "--"))))

(defn- ->key [opt]
  (-> opt
      (string/replace-first "--" "")
      keyword))

(defn- ->val [opt arg numeric-opts]
  (if (contains? numeric-opts (->key opt))
    (read-string arg)
    arg))

(defn parse-args
  ([args] (parse-args args {} #{}))
  ([args default-cfg numeric-opts]
   (merge default-cfg
          (loop [cfg {}
                 args args]
            (let [[opt arg & args] args]
              (if (nil? opt)
                cfg
                (if (arg? arg)
                  (recur (assoc cfg (->key opt) (->val opt arg numeric-opts)) args)
                  (recur (assoc cfg (->key opt) true) (cons arg args)))))))))

(println (parse-args program-arguments))