Summary:
Update pest to 2.1.0.
This version has a new behaviour for parser error messages: the line feed at
the end of the line is shown in the error output.
Reviewed By: wez
Differential Revision: D13671099
fbshipit-source-id: b8d1142a44a56a0b21b3b72cf027f3f8a30f421e
Summary: This would provide information about performance changes.
Reviewed By: singhsrb
Differential Revision: D9620252
fbshipit-source-id: 51d243b50b349c63e552bd1c43db17497025f73a
Summary:
Switch to indexmap, which is more actively maintained than linked-hash-map.
There is no visible performance difference when parsing large config files.
Reviewed By: DurhamG
Differential Revision: D8960870
fbshipit-source-id: 8d6650e2d8b14989061dceb2081a3f93004cea76
Summary:
`home_dir` in stdlib is going to be deprecated. Therefore switch to
external crate.
Reviewed By: DurhamG
Differential Revision: D8960874
fbshipit-source-id: e123debc5c58e6a632a801dedcd9fc6834cb1f65
Summary:
[pest](https://github.com/pest-parser/pest) is an elegant Rust library for
parsing text.
A navie benchmark on a 1MB config file shows pest is about 1.5 to 2x slower.
But the better error message and cleaner code seems worth it.
Practically, in a VirtualBox VM, parsing a set of our config files takes 3-7ms.
The overhead seems to be opening too many files. Reducing it to one file makes
parsing complete in 2-4ms.
Unfortunately the buck build has issues with the elegant syntax
`#[grammar = "spec.pest"]`, because "spec.pest" cannot be located by pest_derive.
Therefore a workaround is used to generate the parser.
The motivation behind this is because I noticed multi-line value can not be
taken as a plain Bytes slice. For example:
[section]
foo = line1
line2
"foo" should be "line1\nline2", instead of "line1\n line2". It does not make a
difference on configlist. But it affects templates. Rather than making the
parser more complex, it seems better to just adopt a reasonbly fast parsing
library.
Reviewed By: DurhamG
Differential Revision: D8960876
fbshipit-source-id: 2fa04e38b706f7126008512732c9efa168f84cc7
Summary: This will be used to parse hgrc-like config files.
Reviewed By: mitrandir77
Differential Revision: D8777330
fbshipit-source-id: 73a114df36e23246a3fc1206be202fba8705453a
