Bug #10476: String.strip remove characters different than pure whitespace

• Status: Closed
• Assignee: zzak (zzak _)
• Target version: 2.2.0
• ruby -v: ruby 2.1.3p242
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN

[yld (Yves Le Douaron)]

The offical documentation (http://www.ruby-doc.org/core-2.1.4/String.html#method-i-strip) says:
strip → new_str

Returns a copy of str with leading and trailing whitespace removed.

But

[9] pry(main)> "#{0.chr}#{9.chr}#{10.chr}#{11.chr}#{12.chr}#{13.chr}#{32.chr}" 
=> "\x00\t\n\v\f\r " 
[10] pry(main)> "#{0.chr}#{9.chr}#{10.chr}#{11.chr}#{12.chr}#{13.chr}#{32.chr}".length
=> 7
[11] pry(main)> "#{0.chr}#{9.chr}#{10.chr}#{11.chr}#{12.chr}#{13.chr}#{32.chr}".strip
=> "" 

([4] pry(main)> (0..255).each { |char| puts "char #{char} stripped" if char.chr.strip.empty? }
char 0 stripped
char 9 stripped
char 10 stripped
char 11 stripped
char 12 stripped
char 13 stripped
char 32 stripped

Stripped characters are

1. Null char (0)
2. Horizontal Tab (9)
3. Line Feed (10)
4. Vertical Tab (11)
5. Form Feed (12)
6. Carriage Return (13)
7. Space (32)

[yld (Yves Le Douaron)]

With the old 1.8.7 interpreter, the behaviour of strip was different:

1.8.7-head :010 > "#{0.chr}#{9.chr}#{10.chr}#{11.chr}#{12.chr}#{13.chr}#{32.chr}".strip
 => "\000" 
1.8.7-head :011 > "#{0.chr}#{9.chr}#{10.chr}#{11.chr}#{12.chr}#{13.chr}#{32.chr}.#{0.chr}".strip
 => "\000\t\n\v\f\r ."

The null character was stripped from the end of the string but not from the beginning...

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Rejected

As the example in the doc states, "whitespace" includes these characters.

[yld (Yves Le Douaron)]

The example only includes 4 of these 7 characters, null, form feed and vertical tab are missing.

Maybe a documentation update could be usefull?

[nobu (Nobuyoshi Nakada)]

• Category changed from core to doc
• Status changed from Rejected to Assigned
• Assignee changed from core to zzak (zzak _)

Yes, definitely.

• File bug-10476.patch bug-10476.patch added

How about something like this?

[yld (Yves Le Douaron)]

It looks perfect.

[ayumin (Ayumu AIZAWA)]

• Status changed from Assigned to Closed
• % Done changed from 0 to 100

Applied in changeset r49135.

---

• string.c: improve docs for String#strip and variations. [ruby-core:66081][Bug #10476]