From: "colindkelley (Colin Kelley)" <colin@...>
Date: 2013-12-29T08:47:48+09:00
Subject: [ruby-core:59369] [ruby-trunk - Feature #9278] Magic comment	"immutable: string" makes "literal".freeze the default for that file


Issue #9278 has been updated by colindkelley (Colin Kelley).


With the 'immutable: string' magic comment, this benchmark runs 1.6X faster (that is, in 61% of the time) compared to stock Ruby 2.1.0.

https://gist.github.com/ColinDKelley/8156708
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Feature #9278: Magic comment "immutable: string" makes "literal".freeze the default for that file
https://bugs.ruby-lang.org/issues/9278#change-43935

Author: colindkelley (Colin Kelley)
Status: Open
Priority: Normal
Assignee: 
Category: core
Target version: 2.1.0


Building on https://bugs.ruby-lang.org/issues/9042, this pull request adds the magic comment # -*- immutable: string -*- that implies .freeze on every string literal in the file. To get a mutable string in a file that starts with the magic comment, use String.new or ''.dup.

Here is a corresponding github pull request:

    https://github.com/ruby/ruby/pull/487

For more details, background, and rationale, please see this blog post:

    http://development.invoca.com/magic-comment-immutable-string-makes-ruby-2-1s-literal-freeze-optimization-the-default/


-- 
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