[augeas-devel] Wildcarded key/value pairs and nested blocks (dovecot lens development)

[Serge Smetana]

Sure. Will do.

On Thu, Mar 7, 2013 at 8:12 PM, Raphaël Pinson
<raphael.pinson at camptocamp.com> wrote:
> Great! We'd surely welcome a Pull Request. In that case, could you adjust
> the license to use LGPLv2+ as the rest of Augeas, and use NaturalDocs
> documentation in comments (see keepalived.aug for example)?
>
>
>
> On Thu, Mar 7, 2013 at 7:06 PM, Serge Smetana <serge.smetana at gmail.com>
> wrote:
>>
>> Hi Raphaël,
>>
>> Thank you very much. I finally understood Build.block* and recursive
>> lenses.
>> Please find the final lens here
>>
>> https://github.com/smetana/augeas/blob/00f125a39e2fc9512df8deb779650673a4da4609/lenses/dovecot.aug
>>
>> If you like it I can make pull request to augeas repository.
>>
>> Thank you,
>> Serge
>>
>> On Thu, Mar 7, 2013 at 6:00 PM, Raphaël Pinson
>> <raphael.pinson at camptocamp.com> wrote:
>> >
>> >
>> > On Thu, Mar 7, 2013 at 4:33 PM, Serge Smetana <serge.smetana at gmail.com>
>> > wrote:
>> >>
>> >> Hi Raphaël,
>> >>
>> >> Trying to use Build.block_newlines construct
>> >>
>> >>    let any = Rx.no_spaces
>> >>    let value = any . (Rx.space . any)*
>> >>    let commands  = /include|include_try/
>> >>    let block_names =
>> >> /dict|userdb|passdb|protocol|service|plugin|namespace|map/
>> >>    let nested_block_names =
>> >> /fields|unix_listener|fifo_listener|inet_listener/
>> >>    let keys = Rx.word - commands - block_names - nested_block_names
>> >
>> >
>> > This kind of constructs makes augparse (and run) verrrrrrrrrrrrry
>> > slooooow.
>> > It is best to rewrite them as:
>> >
>> >    let keys = Rx.word - (commands | block_names | nested_block_names)
>> >
>> > which is strictly equivalent, but much faster.
>> >
>> >
>> >>
>> >>
>> >>    let entry = [ indent . key keys. eq . (Sep.opt_space . store value)?
>> >> .
>> >> eol ]
>> >>    let command = [ command_start . key commands . Sep.space . store
>> >> Rx.fspath . eol ]
>> >>
>> >>    let block_args   = Sep.space . store any
>> >>
>> >>    let nested_block = [ indent . key block_names . block_args? .
>> >> Build.block_newlines entry comment . eol ]
>> >>    let block = [ indent . key block_names . block_args? .
>> >> Build.block_newlines (entry|nested_block)* comment . eol]
>> >>
>> >>    let lns = (comment|empty|entry|command|block)*
>> >>
>> >> If I try to compile this I get an exception: ambiguous concatenation
>> >>
>> >>       First regexp: /([
>> >> \t]*)(dict|userdb|passdb|protocol|service|plugin|namespace|map)((([
>> >> \t]+)([^ \t\n]+))?)/
>> >>       Second regexp: /([ \t\n]+\\{([ \t\n]*\n)?)((((([
>> >> \t]*)((dict[.0-9A-Z_a-z-][.0-9A-Z_a-z-]| ...... <long regexp
>> >> here>.....
>> >>
>> >>       'userdb {# {\n}' can be split into
>> >>       'userdb|=| {# {\n}'
>> >>
>> >>      and
>> >>       'userdb {#|=| {\n}'
>> >>
>> >>
>> >> I guess this is because of optional block_args? in lens definition.
>> >
>> >
>> >
>> > Yes, precisely. Spaces must belong only to one side of two concatenated
>> > expressions.
>> >
>> >
>> >>
>> >> But my old variant without Build.block* construct works:
>> >>
>> >>   let block_open        = del /[ \t]*\{/ "{"
>> >>   let block_close       = del /\}/ "}"
>> >>
>> >>   .... same as above
>> >>
>> >>   let nested_block =
>> >>        [ indent . key nested_block_names . block_args? . block_open .
>> >> eol
>> >>        . (entry | empty | comment)*
>> >>        . indent . block_close . eol ]
>> >>
>> >>    let block =
>> >>        [ indent . key block_names . block_args? . block_open . eol
>> >>        . (entry | empty | comment | nested_block )*
>> >>       . indent . block_close . eol ]
>> >
>> >
>> >
>> > Build.block_newlines allows things like
>> >
>> >     unix_listener {# {\n}
>> >
>> > where "# {\n" should be a comment.
>> >
>> > However, block_args? allows *any* character (including "#" and "{") to
>> > be
>> > present between the key and the opening bracket. I think block_args
>> > should
>> > be refined to only allow the characters you need.
>> >
>> >
>> > Regards,
>> >
>> > --
>> > Raphaël Pinson
>> > Administrateur Systèmes & Réseaux
>> > Camptocamp France
>> > Savoie Technolac
>> > BP 352
>> > 48, avenue du Lac du Bourget
>> > 73372 Le Bourget du Lac, Cedex
>> > www.camptocamp.com
>
>
>
>
> --
> Raphaël Pinson
> Administrateur Systèmes & Réseaux
> Camptocamp France
> Savoie Technolac
> BP 352
> 48, avenue du Lac du Bourget
> 73372 Le Bourget du Lac, Cedex
> www.camptocamp.com