以下が手順
pryはあらかじめインストールしておく
pryを起動
$ pry
Arrayクラスへcdで入る
[1] pry(main)> cd Array
Arrayクラスで使用可能なメソッド一覧をlsで表示
[2] pry(Array):1> ls
Array.methods: [] try_convert
Array#methods:
& concat hash product slice
* count include? push slice!
+ cycle index rassoc sort
- delete insert reject sort!
<< delete_at inspect reject! sort_by!
<=> delete_if join repeated_combination sum
== difference keep_if repeated_permutation take
[] dig last replace take_while
[]= drop length reverse to_a
all? drop_while map reverse! to_ary
any? each map! reverse_each to_h
append each_index max rindex to_s
assoc empty? min rotate transpose
at eql? none? rotate! union
bsearch fetch one? sample uniq
bsearch_index fill pack select uniq!
clear filter permutation select! unshift
collect filter! place shelljoin values_at
collect! find_index pop shift zip
combination first prepend shuffle |
compact flatten pretty_print shuffle!
compact! flatten! pretty_print_cycle size
locals: _ __ _dir_ _ex_ _file_ _in_ _out_ _pry_
show-source [メソッド名]でメソッドの詳細を確認できるが、gemのpry-docがインストールされていないと表示されない（c言語で書かれたメソッドであるため）
[3] pry(Array):1> show-source to_a
From: array.c (C Method):
Owner: Array
Visibility: public
Number of lines: 10
static VALUE
rb_ary_to_a(VALUE ary)
{
if (rb_obj_class(ary) != rb_cArray) {
VALUE dup = rb_ary_new2(RARRAY_LEN(ary));
rb_ary_replace(dup, ary);
return dup;
}
return ary;
}