Re: value "on"=True in pyyaml?

This is an example of one of the biggest issues with the state of modern
day YAML. I'd bet no 2 implementations do the same thing wrt implicit
typing of plain scalars.

I think we need to retire http://yaml.org/type/

It's an idea from over 10 years ago that was well meaning but turned out
poorly. People making new YAML frameworks still use this info.

I am currently of the opinion that:

   - Plain scalars in block context should only implicitly type to numbers,
   strings or null
      - Only JSON numerics are typed to !!int or !!float
      - Plain (unquoted) empty value is typed to !!null
      - Everything else is typed to !!str
   - Booleans should migrate to only supporting !!true and !!false
      - Loaders using a default schema should support !true !false (and
      !null)
      - The plain values of true and false should become strings
      - This might take a while to get everyone on board
   - Plain scalars in flow context should behave same as JSON.
      - Empty values are !!null
   - We should ditch octal, binary etc as possible implicit typing of
   numbers
   - We should ditch the (22 of them!!) special plain values that become
   boolean
      - Only true and false. In flow context. Lowercase.

We can still keep the tag:yaml.org,2002 types, but we need to get out of
the implicit grab bag business. It will be the death of YAML!

---

Related to that, is the concept that every YAML loader loads YAML to native
objects under the direction of a "schema"; but currently that "schema" is
baked into the code implementing loader.

If we had a schema language, then all loaders could load YAML according to
a textual (thus easily reasonable) guide. Schemas could even be written for
loaders that didn't yet support them (as part of their doc) so that people
would know what to expect from their baked in behavior.

More importantly, schemas could be written for popular YAML uses like, say,
Ansible or TravisCI that need values loaded a particular way. These schemas
could even be made to implicitly type true/false/null scalars, for
backwards compat.


On Mon, Feb 29, 2016 at 7:41 AM, Oren Ben-Kiki <[email protected]> wrote:

> This is old YAML 1.0/1.1 proposed schema behavior. It was deprecated (to
> maximize JSON compatibility among other reasons).
>
> On Mon, Feb 29, 2016 at 5:20 PM, <[email protected]> wrote:
>
>> Is this as expected?
>>
>>
>> kbriggs> cat yaml_on.py
>>
>>
>> import yaml
>> x="""
>>  0: on
>>  1: ON
>>  2: 'ON'
>> """
>> print yaml.load(x)
>>
>>
>> kbriggs> python yaml_on.py
>> {0: True, 1: True, 2: 'ON'}
>>
>>
>>
>> Keith
>>
>>
>> ------------------------------------------------------------------------------
>> Site24x7 APM Insight: Get Deep Visibility into Application Performance
>> APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month
>> Monitor end-to-end web transactions and take corrective actions now
>> Troubleshoot faster and improve end-user experience. Signup Now!
>> http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140
>> _______________________________________________
>> Yaml-core mailing list
>> [email protected]
>> https://lists.sourceforge.net/lists/listinfo/yaml-core
>>
>>
>
>
> ------------------------------------------------------------------------------
> Site24x7 APM Insight: Get Deep Visibility into Application Performance
> APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month
> Monitor end-to-end web transactions and take corrective actions now
> Troubleshoot faster and improve end-user experience. Signup Now!
> http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140
> _______________________________________________
> Yaml-core mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/yaml-core
>
>

------------------------------------------------------------------------------
Site24x7 APM Insight: Get Deep Visibility into Application Performance
APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month
Monitor end-to-end web transactions and take corrective actions now
Troubleshoot faster and improve end-user experience. Signup Now!
http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140

_______________________________________________
Yaml-core mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/yaml-core