From: "mame (Yusuke Endoh)" <mame@...>
Date: 2012-03-29T01:33:20+09:00
Subject: [ruby-core:43804] [ruby-trunk - Feature #5798][Assigned] Range#include? needs some optimization


Issue #5798 has been updated by mame (Yusuke Endoh).

Status changed from Open to Assigned
Assignee set to matz (Yukihiro Matsumoto)


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Feature #5798: Range#include? needs some optimization
https://bugs.ruby-lang.org/issues/5798#change-25309

Author: yimutang (Joey Zhou)
Status: Assigned
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: 
Target version: 


For example:

('aa'..'az').include? 123

it seems that the procedure is:

1. check whether 'aa' == 123 # false
2. 'aa'.succ # 'ab'
3. check whether 'ab' == 123 # false
4. 'ab'.succ # 'ac'
5. check whether 'ac' == 123 # false
...
n-1. 'ay'.succ # 'az'
n. check whether 'az' == 123 # false
finally return false

However, 'aa' and 123 are not the same class. It's not necessary to take the whole steps of 'succ' and '=='.
Maybe it should check 'aa'.class and 123.class first, or use <=> instead of == to check, when 'aa' <=> 123 returns nil(== only returns true/false, no nil), the procedure breaks.



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