Cannot parse assert_type lambda

[PierreR]

I guess this is similar to #200.

Would it be possible to support the following idiom:

 assert_type(Pattern[/^(aufs|devicemapper|btrfs|overlay|overlay2|vfs|zfs)$/], $storage_driver) |$a, $b| {
...
}

It is used for instance in https://github.com/puppetlabs/puppetlabs-docker/blob/master/manifests/init.pp#L529

It is currently failing to parse with:

x swarm.worker.testing: cannot parse ./modules/docker/manifests/init.pp:492:68:
    |
492 |     assert_type(Pattern[/^(Debian|RedHat|windows)$/], $::osfamily) |$a, $b| {
    |                                                                    ^
unexpected '|'
expecting '}' or Statement
 at ./modules/profile/manifests/docker.pp:116:5

[bartavelle]

It is indeed similar to #200.

[bartavelle]

It is possible to support such functions in an ad-hoc way, but it would be nice to have a principled way.

[bartavelle]

Alright, I changed stuff in the parser, you should have a new error for this, and for #200 !

[bartavelle]

(Please tell me this is the case)

[PierreR]

Unless I am missing something, I have the same error:

x swarm.worker.testing: cannot parse ./modules/docker/manifests/init.pp:491:68:
    |
491 |     assert_type(Pattern[/^(Debian|RedHat|windows)$/], $::osfamily) |$a, $b| {
    |                                                                    ^
unexpected '|'
expecting '}' or Statement

[PierreR]

ouch that's wicked. The lexer spec tests are not running on travis for some reason.

When I do a cabal test these tests are failing ...

[bartavelle]

I think that if you remove the type as the first argument, you would have another parsing error. This is yet another parsing problem. I think it would be nice to have a formal grammar for the language, but this will probably not happen ...

[PierreR]

I am not so sure because this is failing the same way and there is not type annotation:

class application::role::swarm::test (
) {
  $fruit = with("apples", "oranges", "bananas") |$x, $y, $z| {
    "${x}, ${y}, and ${z}"
  }
  notify {"${fruit}":}
}

ERROR: (swarm.manager.dev) cannot parse ./modules/application/manifests/role/swarm/test.pp:3:49:
  |
3 |   $fruit = with("apples", "oranges", "bananas") |$x, $y, $z| {
  |                                                 ^
unexpected '|'
expecting "!=", "!~", "<<", "<=", "==", "=~", ">=", ">>", "and", "in", "or", '*', '+', '-', '.', '/', '<', '>', '[', '}', or Statement
 at ./modules/application/manifests/role/swarm/manager.pp:2:3

[bartavelle]

right, this is getting problematic :) I think it is time to rewrite the parser from scratch, using something like happy

[PierreR]

This is well above my head but I would be quite interested to know more precisely why megaparsec isn't a good fit anymore (as I find parser quite fascinating in general) ;-)

[bartavelle]

It is not that, it is just that all the parsers are applied in order, and it is really hard for my feeble mind to understand what it means and what their interactions are.

A tool like happy can tell you where you have "conflicts", that is parts of your parsers that parse the "same thing".

[bartavelle]

But in theory megaparsec does the job just fine!

[PierreR]

So the plan would be the rewrite the parser with megaparsec with the help of something like happy to understand the interaction more.

[bartavelle]

I don't know at all. The plan right now would be to find some description of the language, so that I am not chasing randomly using only examples.

[PierreR]

This might be helpful ?

[PierreR]

I suspect the problem comes from the lambdaCall parser particularly the line that parses the with argument (list of expression separated by a comma) ? https://github.com/bartavelle/language-puppet/blob/master/src/Puppet/Parser.hs What do you think ?

[PierreR]

Maybe _hoLambdaExpr should be Vector Expression ?

[PierreR]

https://github.com/puppetlabs/puppet-specifications/blob/4e54d7a8c1e8f16c1cdbc44d4b5537c27784e7cd/language/calls.md#arguments

[bartavelle]

It is very helpful!

[bartavelle]

Oh right, that is the problem!

[bartavelle]

Do you want to try fixing this?

[PierreR]

No really ;-) I have had a go fixing the parser but then there are still many bits to change in resolve and I am not sure I know fully what I am doing. But if you don't have the time, I can give it a proper try if you prefer.

[bartavelle]

I just added the function. But I did not write tests for it :/

[PierreR]

It works !