Bug #1552

String#strip! raises RuntimeError on Frozen String Despite Making No Changes

Added by runpaint (Run Paint Run Run) about 8 years ago. Updated about 6 years ago.

Target version:
ruby -v:
ruby 1.9.2dev (2009-05-28 trunk 23601) [i686-linux]


Calling String#strip! on a frozen string raises a RuntimeError even if the string was not changed. String#rstrip! doesn't raise an exception in this scenario. I believe that the latter behaviour is correct; #strip! should only raise a RuntimeError if the string would be changed.

$ rubybleed -ve '"ruby".freeze.strip!'
ruby 1.9.2dev (2009-05-28 trunk 23601) [i686-linux]
-e:1:in strip!': can't modify frozen string (RuntimeError)
from -e:1:in

$ rubybleed -ve '"ruby".freeze.rstrip!'
ruby 1.9.2dev (2009-05-28 trunk 23601) [i686-linux]

1.9.1 behaves the same as 1.9.2. 1.8.7 behaves correctly.

Associated revisions

Revision 58880
Added by watson1978 (Shizuo Fujita) 29 days ago

Improve performance of rb_equal()

  • object.c (rb_equal): add optimized path to compare the objects using
    rb_equal_opt(). Previously, if not same objects were given, rb_equal() would
    call `==' method via rb_funcall() which took a long time.

    rb_equal_opt() has provided faster comparing for Fixnum/Float/String objects.
    Now, Time#eql? uses rb_equal() to compare with argument object and it will
    be faster around 40% on 64-bit environment.

  • array.c (rb_ary_index): remove redundant rb_equal_opt() calling.
    Now, rb_equal() was optimized using rb_equal_opt().
    If rb_equal_opt() returns Qundef, it will invoke rb_equal() -> rb_equal_opt(),
    and it will cause the performance regression.

    So, this patch will remove first redundant rb_equal_opt() calling.

  • array.c (rb_ary_rindex): ditto.

  • array.c (rb_ary_includes): ditto.

    [Bug #13365] [Fix GH-#1552]


Time#eql? with other 7.309M (± 1.4%) i/s - 36.647M in 5.014964s
Array#index(val) 1.433M (± 1.2%) i/s - 7.207M in 5.030942s
Array#rindex(val) 1.418M (± 1.6%) i/s - 7.103M in 5.009164s
Array#include?(val) 1.451M (± 0.9%) i/s - 7.295M in 5.026392s


Time#eql? with other 10.321M (± 1.9%) i/s - 51.684M in 5.009203s
Array#index(val) 1.474M (± 0.9%) i/s - 7.433M in 5.044384s
Array#rindex(val) 1.449M (± 1.7%) i/s - 7.292M in 5.034436s
Array#include?(val) 1.466M (± 1.7%) i/s - 7.373M in 5.030047s

Test code

require 'benchmark/ips'

Benchmark.ips do |x|
t1 =
t2 = "Time#eql? with other" do |i|
i.times { t1.eql?(t2) }

# Benchmarks to check whether it didn't introduce the regression
obj = "Array#index(val)" do |i|
ary = [1, 2, true, false, obj]
i.times { ary.index(obj) }
end "Array#rindex(val)" do |i|
ary = [1, 2, true, false, obj].reverse
i.times { ary.rindex(obj) }
end "Array#include?(val)" do |i|
ary = [1, 2, true, false, obj]
i.times { ary.include?(obj) }


#1 Updated by matz (Yukihiro Matsumoto) about 8 years ago

  • Status changed from Open to Closed

changed to the opposite way for consistency.

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