tabs indentation is not considered as invalid

Tab indentation will basically result as a non-char when parsing YAML.

For instance:

a:
        b:
                c: yo mamma

As tab indented comes out as:

js-yaml test.yaml 

{ a: null, b: null, c: 'yo mamma' }

It would be safer and easier to debug if the file would not be parseable on tab indent.

[puzrin]

Everyone who wish to invent “spec improvements” instead of following standard, can continue in fork. That’s out of this project scope.

[ingydotnet]

Greetings. I am one of the creators of YAML. Tabs are not allowed in indentation and an error should happen when they are detected in a place where indentation might occur.

IMHO libyaml is the most perfect implementation of the YAML 1.1 spec (which is very close to YAML 1.2).

Here is the result of the OP test in Perl’s libyaml binding: https://gist.github.com/ac5821875eb30979f7a8 Here is the same program in Python: https://gist.github.com/582ea40dbdcd473249a4

They both throw the same error. I believe it is a wise choice to test arguable behaviors against a libyaml binding. Possibly even moreso than the spec.

FWIW, we spent every day for 3 months (circa 2003) trying to sanely allow tabs into YAML indentation. We came to the conclusion that it was an insane endeavor. (It ends up being much harder than, say, Python indentation based scoping).