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;; simple
(defn factorial [n]
  (if (zero? n)
    1
    (* n (factorial (dec n)))))

;; tail recursion
(defn factorial
  ([n] (factorial n 1))
  ([n sum]

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/target
/lib
/classes
/checkouts
pom.xml
pom.xml.asc
*.jar
*.class
.lein-deps-sum
.lein-failures

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(declare ^:dynamic *asdf*)

(let
    [b (binding [*asdf* 10]
         (for [i (range 0 3)]
           (* *asdf* i)))]
  b)
;;; => java.lang.ClassCastException: clojure.lang.Var$Unbound cannot be cast to java.lang.Number

(let

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#!/bin/bash

# named pipe 生成！
mkfifo hoge_pipe

# 実際にそのファイルが存在している
ls -l hoge_pipe

# named pipe からの入力の行数を測るようにセッティング
wc -l < hoge_pipe &

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#!/bin/bash

# bash executes this incorrectly.
# On the other hand zsh executes this correctly.
# Because bash spawns a sub-shell inside while-do loop meanwhile zsh doesn't it.
declare -i sum
seq 0 10 | while read num ; do
  let sum+=$num
done

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#!/bin/bash

foldl(){
	local func="$1"
	local prev="$2"
	while read cur ; do
		prev="$(eval $func "$prev" "$cur")"
	done
	echo $prev
}

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#!/bin/bash

seq 0 10 | {
  declare -i sum
  while read num ; do
    let sum+=$num
  done
  
  # bash => 55 (^^)v
  # zsh => 55

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;;; call/cc を理解しよう！

;; 一見すると普通にかけぬけている
(call/cc (lambda (c) "Just invoke")) ; "Just invoke"

(define boundval (call/cc (lambda (c) "Just invoke")))
boundval ; "Just invoke

;; だが…

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(defun dividable (n m)
  (= (mod n m) 0))

(dividable 6 3)							; => t
(dividable 6 4)							; => nil

(defun euler-1 (begin end)
  (loop for i from begin to (1- end)
		sum (if (or (dividable i 3) (dividable i 5))

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(defun parent-directory (dir)
  (unless (equal "/" dir)
	(file-name-directory (directory-file-name dir))))

(defun find-nearest-file (dir-path filename)
  (let ((file (concat dir-path filename))
		(parent (parent-directory (expand-file-name dir-path))))
	(if (file-exists-p file)
		file
	  (when parent