string literals.
[Feature #11473]
This addition is not specification change, but to try frozen
string literal world discussed on [Feature #11473].
You can try frozen string literal world using this magical line:
RubyVM::InstructionSequence.compile_option =
{frozen_string_literal: true}
Note that this is a global compilation option, so that you need to
compile another script like that:
p 'foo'.frozen? #=> false
RubyVM::InstructionSequence.compile_option =
{frozen_string_literal: true}
p 'foo'.frozen? #=> false, because this line is already compiled.
p eval("'foo'.frozen?") #=> true
Details:
* String literals are deduped by rb_fstring().
* Dynamic string literals ("...#{xyz}...") is now only frozen,
not deduped. Maybe you have other ideas.
Now, please do not use this option on your productions :)
Of course, current specification can be changed.
* compile.c: ditto.
* test/ruby/test_iseq.rb: add a test.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51659 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
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