diff options
author | Étienne Barrié <etienne.barrie@gmail.com> | 2023-12-01 11:33:00 +0100 |
---|---|---|
committer | Jean Boussier <jean.boussier@gmail.com> | 2024-03-19 09:26:49 +0100 |
commit | 12be40ae6be78ac41e8e3f3c313cc6f63e7fa6c4 (patch) | |
tree | f6b81fac770da6b705557623224dbf9b9c2d2847 /spec/ruby/command_line/fixtures/string_literal_mutable_comment.rb | |
parent | 86b15316a748a579dd4fd4df42b6db42accebdc2 (diff) |
Implement chilled strings
[Feature #20205]
As a path toward enabling frozen string literals by default in the future,
this commit introduce "chilled strings". From a user perspective chilled
strings pretend to be frozen, but on the first attempt to mutate them,
they lose their frozen status and emit a warning rather than to raise a
`FrozenError`.
Implementation wise, `rb_compile_option_struct.frozen_string_literal` is
no longer a boolean but a tri-state of `enabled/disabled/unset`.
When code is compiled with frozen string literals neither explictly enabled
or disabled, string literals are compiled with a new `putchilledstring`
instruction. This instruction is identical to `putstring` except it marks
the String with the `STR_CHILLED (FL_USER3)` and `FL_FREEZE` flags.
Chilled strings have the `FL_FREEZE` flag as to minimize the need to check
for chilled strings across the codebase, and to improve compatibility with
C extensions.
Notes:
- `String#freeze`: clears the chilled flag.
- `String#-@`: acts as if the string was mutable.
- `String#+@`: acts as if the string was mutable.
- `String#clone`: copies the chilled flag.
Co-authored-by: Jean Boussier <byroot@ruby-lang.org>
Diffstat (limited to 'spec/ruby/command_line/fixtures/string_literal_mutable_comment.rb')
-rw-r--r-- | spec/ruby/command_line/fixtures/string_literal_mutable_comment.rb | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/spec/ruby/command_line/fixtures/string_literal_mutable_comment.rb b/spec/ruby/command_line/fixtures/string_literal_mutable_comment.rb new file mode 100644 index 0000000000..381a742001 --- /dev/null +++ b/spec/ruby/command_line/fixtures/string_literal_mutable_comment.rb @@ -0,0 +1,4 @@ +# frozen_string_literal: false +frozen = "test".frozen? +interned = "test".equal?("test") +puts "frozen:#{frozen} interned:#{interned}" |