Format for lists and dictionary responses

[SamMousa]

I think a somewhat simpler/easier way forward would be to restrict the output format of the existing commands from YAML to JSON. This ought to be a backwards-compatible change, since all YAML parsers are supposed to be able to read JSON. However, it would be worth testing the major client languages to double-check that they actually do the right thing in that case.

Originally posted by @kr in #610 (comment)

I've thought some more on this and I think going either the YAML or the JSON road is troublesome unless you want to pull in a proper library into beanstalkd.

We could actually simplify the formats as well, since the beanstalkd protocol is a text based protocol and requires a custom parser / interpreter it's not much work to define the lists and dictionaries.

Lists:

• All entries are strings
• Each entry is separate by a \n

This gives you all you need to know, no parsing and more importantly no escaping required.

Dictionary:

• Each entry has a key and a value
• Since we control the keys we can just put strict definitions on them; keys only consist of the alphabet a-z and the character -.
• Values should be interpreted as string unless we specify that they are some other type explicitly.
• Keys and values are separated by a :

These could have trivial implementations in beanstalkd code and to not break existing clients we could implement these as new commands. For example stats-tubes-2 or stats-2.

For me this has no priority by the way, I'm happy parsing the YAML in it's current state and since I'm assuming developers create tube names in a reasonable way (not containing user input) it should cause no issues.

[kr]

Good points! I agree.

[SamMousa]

Would you accept a contribution that implements this as new commands (to not break backwards compatibility)?

At the same time we could then deprecate the old commands.

[kr]

In principle yes, but in practice I probably don't have time to review the code.

If any other maintainer wants to review, go for it!