# To quote or not to quote (I think it's a bug) **URL:** \ **Category:** Ruby\ **Created:** [February 20, 2007, 2:04am UTC](https://www.ruby-forum.com/t/to-quote-or-not-to-quote-i-think-its-a-bug/86121 "2007-02-20T02:04:20Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Matthieu\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/3bc359/32.png) [@Matthieu\_R](https://www.ruby-forum.com/u/Matthieu_R)\ **Post date:** [February 20, 2007, 2:04am UTC](https://www.ruby-forum.com/t/to-quote-or-not-to-quote-i-think-its-a-bug/86121/1 "2007-02-20T02:04:20Z")
Hi, I’m not sure this is the right place to report issues about Syck but that’s the best I’ve found so far 🙂 I think I’ve found a problem with the way Syck quotes strings that could look like floats. Here is a short example: irb(main):001:0\> require ‘yaml’ =\> true irb(main):002:0\> YAML.dump([“1.2”, “1.2.3”, “1.2\_3”]) =\> “— \n- “1.2”\n- 1.2.3\n- 1.2\_3\n” The first element is quoted appropriately, the second isn’t because there’s no ambiguity but the third should be quoted. The YAML float can have underscores, they’re used as visual separators and should be ignored by the parser. So when seeing 1.2\_3 the parser should read the float 1.23. Then to disambiguates the string “1.2\_3” should be quoted. Practically this isn’t really a problem as YAML converts on writes so YAML.dump(1.2\_3) gets directly written as 1.23. However it creates some interoperability issues when “1.2\_3” gest written unquoted by Syck and then read by another parser as being 1.23. The string isn’t a string anymore in that case. What do you think? Thanks, Matthieu R. ---
**Author:** ![Matthieu\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/3bc359/32.png) [@Matthieu\_R](https://www.ruby-forum.com/u/Matthieu_R)\ **Post date:** [February 20, 2007, 5:13am UTC](https://www.ruby-forum.com/t/to-quote-or-not-to-quote-i-think-its-a-bug/86121/2 "2007-02-20T05:13:30Z")
On 2/19/07, Matthieu R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > that case. Are you certain that 1.2\_3 is a valid YAML float? [http://yaml.org/type/float.html](http://yaml.org/type/float.html) I do not believe underscores are valid in either YAML floats or YAML integers. Although they are allowed in Ruby, I believe Syck is handling your example case properly and without ambiguity. Blessings, TwP ---
**Author:** ![Matthieu\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/3bc359/32.png) [@Matthieu\_R](https://www.ruby-forum.com/u/Matthieu_R)\ **Post date:** [February 20, 2007, 5:28am UTC](https://www.ruby-forum.com/t/to-quote-or-not-to-quote-i-think-its-a-bug/86121/3 "2007-02-20T05:28:30Z")
Hi Tim, In that page: “Any “_\__” characters in the number are ignored, allowing a readable representation of large values.” So clearly they’re allowed, in 1.2\_3 the underscore is simply ignored and the parser should undestand 1.23. If I fancy to write my own YAML by hand and make it easily readable (which is kind of the original purpose) I could write 100\_000\_000.03 which would be a nice looking float. Hence the ambiguity with “1.2\_3”. Cheers, Matthieu ---
**Author:** ![Matthieu\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/3bc359/32.png) [@Matthieu\_R](https://www.ruby-forum.com/u/Matthieu_R)\ **Post date:** [February 20, 2007, 6:13am UTC](https://www.ruby-forum.com/t/to-quote-or-not-to-quote-i-think-its-a-bug/86121/4 "2007-02-20T06:13:33Z")
> ambiguity with “1.2\_3”. > But the specification is not just in english, it’s also in regex form: [-+]?([0-9][0-9\_]_)?.[0-9.]_([eE][-+][0-9]+)? (base 10) |[-+]?[0-9][0-9\_]_(:[0-5]?[0-9])+.[0-9\_]_ (base 60) |[-+]?.(inf|Inf|INF) # (infinity) |.(nan|NaN|NAN) # (not a number) For a base 10 number, underscores are permitted only if they appear BEFORE the decimal point, so for 1.2\_3 there is no ambiguity. Dan. ---
**Author:** ![Matthieu\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/3bc359/32.png) [@Matthieu\_R](https://www.ruby-forum.com/u/Matthieu_R)\ **Post date:** [February 20, 2007, 6:25am UTC](https://www.ruby-forum.com/t/to-quote-or-not-to-quote-i-think-its-a-bug/86121/5 "2007-02-20T06:25:33Z")
> So clearly they’re allowed, in 1.2\_3 the underscore is simply > ignored and > the parser should undestand 1.23. If I fancy to write my own > YAML by hand > and make it easily readable (which is kind of the original > purpose) I could > write 100\_000\_000.03 which would be a nice looking float. Hence the > ambiguity with “1.2\_3” Hmmmm… I just noticed that the specification ([Floating-Point Language-Independent Type for YAML™ Version 1.1](http://yaml.org/type/float.html)) isn’t just unclear, it’s inconsistent. The examples listed include: exponentioal: 685.230\_15e+03 Notwithstanding the spelling of exponential, that example is not consistent with the regular expression (which allows underscores only if they preceed the decimal point - [-+]?([0-9][0-9\_]_)?.[0-9.]_([eE][-+][0-9]+)?). Dan. ---
**Author:** ![Matthieu\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/3bc359/32.png) [@Matthieu\_R](https://www.ruby-forum.com/u/Matthieu_R)\ **Post date:** [February 20, 2007, 7:16am UTC](https://www.ruby-forum.com/t/to-quote-or-not-to-quote-i-think-its-a-bug/86121/6 "2007-02-20T07:16:37Z")
On Tue, Feb 20, 2007 at 10:03:25AM +0900, Matthieu R. wrote: > The first element is quoted appropriately, the second isn’t because there’s > no ambiguity but the third should be quoted. The YAML float can have > underscores, they’re used as visual separators and should be ignored by the > parser. Only in YAML 1.1. Syck only speaks YAML 1.0. Unfortunately, the types repository for 1.0 is no longer at [yaml.org](http://yaml.org). See [Float Language-Independent Type For YAML](http://web.archive.org/web/20030815095109/yaml.org/type/float/) for the floats which Syck should support. \_why