2019-03-31 11:00:21 +00:00
---
title: '８章: 真偽値と判断'
author: kazu634
date: 2008-08-05
wordtwit_post_info:
- 'O:8:"stdClass":13:{s:6:"manual";b:0;s:11:"tweet_times";i:1;s:5:"delay";i:0;s:7:"enabled";i:1;s:10:"separation";s:2:"60";s:7:"version";s:3:"3.7";s:14:"tweet_template";b:0;s:6:"status";i:2;s:6:"result";a:0:{}s:13:"tweet_counter";i:2;s:13:"tweet_log_ids";a:1:{i:0;i:4191;}s:9:"hash_tags";a:0:{}s:8:"accounts";a:1:{i:0;s:7:"kazu634";}}'
categories:
- gauche
- Lisp
---
< div class = "section" >
< p >
勉強の続きだよ。
< / p >
< p >
< a name = "seemore" > < / a >
< / p >
< h4 >
型を判定する手続き
< / h4 >
< ul >
< li >
pair?
< / li >
< li >
null?
< / li >
< li >
list?
< / li >
< li >
boolean?
< / li >
< li >
symbol?
< / li >
< li >
number?
< / li >
< li >
char?
< / li >
< li >
string?
< / li >
< / ul >
< h4 >
性質を判定する手続き
< / h4 >
< ul >
< li >
odd?
< / li >
< li >
even?
< / li >
< li >
zero?
< / li >
< li >
exact?
< / li >
< li >
char-alphabetic?
< / li >
< li >
proper-list?
< / li >
< / ul >
< h4 >
not
< / h4 >
< p >
否定だよ。
< / p >
< pre class = "syntax-highlight" >
gosh> < span class = "synSpecial" > (< / span > < span class = "synStatement" > not< / span > < span class = "synSpecial" > (< / span > < span class = "synStatement" > =< / span > < span class = "synConstant" > 2< / span > < span class = "synConstant" > 3< / span > < span class = "synSpecial" > ))< / span >
#<span class="synStatement">t</span>
gosh> < span class = "synSpecial" > (< / span > < span class = "synStatement" > not< / span > < span class = "synSpecial" > (< / span > < span class = "synStatement" > =< / span > < span class = "synConstant" > 2< / span > < span class = "synConstant" > 2< / span > < span class = "synSpecial" > ))< / span >
#f
< / pre >
< h4 >
条件を判断するcase手続き
< / h4 >
< p >
select caseなんかと同じみたいだ。
< / p >
< pre class = "syntax-highlight" >
gosh> < span class = "synSpecial" > (< / span > define < span class = "synSpecial" > (< / span > score card< span class = "synSpecial" > )< / span >
< span class = "synSpecial" > (< / span > < span class = "synStatement" > case< / span > card
< span class = "synSpecial" > ((< / span > A< span class = "synSpecial" > )< / span > < span class = "synConstant" > 11< / span > < span class = "synSpecial" > )< / span >
< span class = "synSpecial" > ((< / span > J Q K< span class = "synSpecial" > )< / span > < span class = "synConstant" > 10< / span > < span class = "synSpecial" > )< / span >
< span class = "synSpecial" > ((< / span > < span class = "synConstant" > 2< / span > < span class = "synConstant" > 3< / span > < span class = "synConstant" > 4< / span > < span class = "synConstant" > 5< / span > < span class = "synConstant" > 6< / span > < span class = "synConstant" > 7< / span > < span class = "synConstant" > 8< / span > < span class = "synConstant" > 9< / span > < span class = "synConstant" > 10< / span > < span class = "synSpecial" > )< / span > card< span class = "synSpecial" > )))< / span >
score
gosh> < span class = "synSpecial" > (< / span > score < span class = "synConstant" > 4< / span > < span class = "synSpecial" > )< / span >
< span class = "synConstant" > 4< / span >
gosh> < span class = "synSpecial" > (< / span > score < span class = "synConstant" > 10< / span > < span class = "synSpecial" > )< / span >
< span class = "synConstant" > 10< / span >
gosh> < span class = "synSpecial" > (< / span > score < span class = "synSpecial" > '< / span > < span class = "synIdentifier" > A< / span > < span class = "synSpecial" > )< / span >
< span class = "synConstant" > 11< / span >
< / pre >
< h4 >
条件が真の時だけ処理を行うwhen手続き
< / h4 >
< p >
これだとif手続きの方がいいのかもしれないけど:
< / p >
< pre class = "syntax-highlight" >
gosh> < span class = "synSpecial" > (< / span > define < span class = "synSpecial" > (< / span > foo num< span class = "synSpecial" > )< / span >
< span class = "synSpecial" > (< / span > < span class = "synStatement" > when< / span > < span class = "synSpecial" > (< / span > < span class = "synStatement" > < < / span > num < span class = "synConstant" > 10< / span > < span class = "synSpecial" > )< / span >
num< span class = "synSpecial" > ))< / span >
foo
gosh> < span class = "synSpecial" > (< / span > foo < span class = "synConstant" > 4< / span > < span class = "synSpecial" > )< / span >
< span class = "synConstant" > 4< / span >
gosh> < span class = "synSpecial" > (< / span > foo < span class = "synConstant" > 11< / span > < span class = "synSpecial" > )< / span >
#<undef>
< / pre >
< p >
ちなみに条件式が偽のときだけ式を評価させたい場合はunlessを用いるよん。
< / p >
< h4 >
1から任意の整数までの和を足しあわせた結果を表示
< / h4 >
< p >
こんなんでいいのかー。すごく短い。
< / p >
< pre class = "syntax-highlight" >
gosh> < span class = "synSpecial" > (< / span > define < span class = "synSpecial" > (< / span > sum n< span class = "synSpecial" > )< / span >
< span class = "synSpecial" > (< / span > < span class = "synStatement" > if< / span > < span class = "synSpecial" > (< / span > < span class = "synStatement" > =< / span > n < span class = "synConstant" > 1< / span > < span class = "synSpecial" > )< / span >
< span class = "synConstant" > 1< / span >
< span class = "synSpecial" > (< / span > < span class = "synStatement" > +< / span > < span class = "synSpecial" > (< / span > sum < span class = "synSpecial" > (< / span > < span class = "synStatement" > -< / span > n < span class = "synConstant" > 1< / span > < span class = "synSpecial" > ))< / span > n< span class = "synSpecial" > )))< / span >
sum
gosh> < span class = "synSpecial" > (< / span > sum < span class = "synConstant" > 10< / span > < span class = "synSpecial" > )< / span >
< span class = "synConstant" > 55< / span >
< / pre >
< p >
Cだとこんな感じかしら？
< / p >
< pre class = "syntax-highlight" >
< span class = "synComment" > /* ======================= */< / span >
< span class = "synComment" > /* === Include library === */< / span >
< span class = "synComment" > /* ======================= */< / span >
< span class = "synPreProc" > #include < / span > < span class = "synConstant" > < stdio.h> < / span >
< span class = "synPreProc" > #include < / span > < span class = "synConstant" > < stdlib.h> < / span >
< span class = "synComment" > /* ============ */< / span >
< span class = "synComment" > /* === main === */< / span >
< span class = "synComment" > /* ============ */< / span >
< span class = "synType" > int< / span > main(< span class = "synType" > int< / span > argc, < span class = "synType" > char< / span > *argv[])
{
< span class = "synType" > int< / span > i = < span class = "synConstant" > < / span > ;
< span class = "synType" > int< / span > sum = < span class = "synConstant" > < / span > ;
< span class = "synType" > int< / span > num = atoi(argv[< span class = "synConstant" > 1< / span > ]);
< span class = "synStatement" > for< / span > (i = < span class = "synConstant" > < / span > ; i < = num; ++i)
{
sum += i;
}
printf(< span class = "synConstant" > " </ span >< span class = "synSpecial" > %d\n</ span >< span class = "synConstant" > " </ span > , sum);
}
< / pre >
< p >
発想が全然違う気がする。
< / p >
< blockquote >
< ul >
< li >
「gauche」に関連する最近のエントリ < ul >
< li >
< a href = "http://d.hatena.ne.jp/sirocco634/20080804/1217853753" onclick = "__gaTracker('send', 'event', 'outbound-article', 'http://d.hatena.ne.jp/sirocco634/20080804/1217853753', ' 等価性 – 武蔵の日記');" target = "_blank" > 等価性 – 武蔵の日記< / a >
< / li >
< li >
< a href = "http://d.hatena.ne.jp/sirocco634/20080803/1217768505" onclick = "__gaTracker('send', 'event', 'outbound-article', 'http://d.hatena.ne.jp/sirocco634/20080803/1217768505', ' 複数の引数をとる手続きだよ – 武蔵の日記');" target = "_blank" > 複数の引数をとる手続きだよ – 武蔵の日記< / a >
< / li >
< li >
< a href = "http://d.hatena.ne.jp/sirocco634/20080802/1217685822" onclick = "__gaTracker('send', 'event', 'outbound-article', 'http://d.hatena.ne.jp/sirocco634/20080802/1217685822', ' 『プログラミングGauche』の勉強 – 武蔵の日記');" target = "_blank" > 『プログラミングGauche』の勉強 – 武蔵の日記< / a >
< / li >
< li >
< a href = "http://d.hatena.ne.jp/sirocco634/20080729/1217342129" onclick = "__gaTracker('send', 'event', 'outbound-article', 'http://d.hatena.ne.jp/sirocco634/20080729/1217342129', ' lambdaでてきた – 武蔵の日記');" target = "_blank" > lambdaでてきた – 武蔵の日記< / a >
< / li >
< li >
< a href = "http://d.hatena.ne.jp/sirocco634/20080727/1217160745" onclick = "__gaTracker('send', 'event', 'outbound-article', 'http://d.hatena.ne.jp/sirocco634/20080727/1217160745', ' Hello world! – 武蔵の日記');" target = "_blank" > Hello world! – 武蔵の日記< / a >
< / li >
< / ul >
< / li >
< / ul >
< / blockquote >
2019-04-02 16:06:15 +00:00
< / div >
