The Elegant Parser
Full Changelog: https://github.com/pest-parser/pest/compare/v2.6.0...v2.6.1
pest v2.6.1 contains a patch for the longstanding problem that pest couldn't be used as a git dependency due to the bootstrapping process. It should be possible now with a special feature flag as follows:
pest = { git = "https://github.com/.../pest.git", rev = "..." }
pest_derive = { git = "https://github.com/.../pest.git", rev = "...", features = ["not-bootstrap-in-src"]}
Note that the compilation time will be higher due to the cargo library dependency. If that becomes an issue, you can still use the old workarounds, e.g. cloning the repo, running cargo bootstrap there and specifying the dependency as a path to the locally cloned repo instead of git.
Note that the node tag feature in 2.6.0 was a technically semver-breaking change even though it is a backwards-compatible / non-breaking change in the meta-grammar. There may be similar non-breaking changes to the meta-grammar between minor versions in the future. These non-breaking changes, however, may translate into semver-breaking changes due to the additional variants propagated from the generated Rule enum. This is a known issue and will be fixed in the future (e.g. by increasing MSRV and non_exhaustive annotations).
If you face a dependency problem where Cargo mixes different versions of pest due to transitive dependencies: https://github.com/pest-parser/pest/issues/849#issuecomment-1525505256 you can try adding the older pest to explicitly force it as follows:
pest = { version = "=2.5.6" }
node_tag, iterator, and meta grammar by @tomtau in https://github.com/pest-parser/pest/pull/832
//!, /// or //, allow writing empty pest grammar. by @huacnlee in https://github.com/pest-parser/pest/pull/839
ExactSizeIterator for Pair iterators by @MucTepDayH16 in https://github.com/pest-parser/pest/pull/833
Full Changelog: https://github.com/pest-parser/pest/compare/v2.5.7...v2.6.0
pest v2.6.0's grammar includes a new (optional) feature for labelling parts of rules (based on this idea posted by @oovm : https://github.com/pest-parser/pest/discussions/550 ), e.g.:
add = {#lhs = expr ~ "+" ~ #rhs = epxr}
This feature can help to distinguish tokens by labels instead of positions (which can help to reduce boilerplate code). You can read more about it here: https://pest.rs/book/grammars/syntax.html#tags
Note that the node tag feature in 2.6.0 is a technically semver-breaking change even though it is a backwards-compatible / non-breaking change in the meta-grammar. There may be similar non-breaking changes to the meta-grammar between minor versions in the future. These non-breaking changes, however, may translate into semver-breaking changes due to the additional variants propagated from the generated Rule enum. This is a known issue and will be fixed in the future (e.g. by increasing MSRV and non_exhaustive annotations).
Full Changelog: https://github.com/pest-parser/pest/compare/v2.5.6...v2.5.7
//// parsing error. by @huacnlee in https://github.com/pest-parser/pest/pull/818
Full Changelog: https://github.com/pest-parser/pest/compare/v2.5.5...v2.5.6
Thanks to the great work of @huacnlee , @Jamalam360 and others, the new version of pest_fmt was published and the Visual Studio Code extension for pest was released on the Marketplace: https://marketplace.visualstudio.com/items?itemName=pest.pest-ide-tools
Rule::line_doc for fix #781 "already defined" error. by @huacnlee in https://github.com/pest-parser/pest/pull/782
LineIndex instead of Pairs::move_cursor for improve Pairs::next and Pair::line_col performance. by @huacnlee in https://github.com/pest-parser/pest/pull/785
Full Changelog: https://github.com/pest-parser/pest/compare/v2.5.4...v2.5.5
The "fast-col-line" feature was removed, because it's superseded by the line_col method on Pairs (which has a better or similar performance): https://github.com/pest-parser/pest/pull/785#issuecomment-1413604569
Note that the rustdoc support in 2.5.4: https://github.com/pest-parser/pest/pull/765 was a semver-breaking change even though it was a backwards-compatible / non-breaking change in the meta-grammar. There may be similar non-breaking changes to the meta-grammar
between minor versions in the future. These non-breaking changes, however, may translate into semver-breaking changes due to the additional variants propagated from the generated Rule enum. This is a known issue and will be fixed in the future (e.g. by increasing MSRV and non_exhaustive annotations).
col calculate for pair.line_col method, and add integration test for cover it. by @huacnlee in https://github.com/pest-parser/pest/pull/768
#[default] compile error. by @huacnlee in https://github.com/pest-parser/pest/pull/770
/// and //! syntax for add doc comment for rules. by @huacnlee in https://github.com/pest-parser/pest/pull/765
Full Changelog: https://github.com/pest-parser/pest/compare/v2.5.3...v2.5.4
Full Changelog: https://github.com/pest-parser/pest/compare/v2.5.2...v2.5.3
Full Changelog: https://github.com/pest-parser/pest/compare/v2.5.1...v2.5.2
pest_debugger by @dffdff2423 in https://github.com/pest-parser/pest/pull/740
skip_until using SIMD memchr by @tomtau in https://github.com/pest-parser/pest/pull/745
it can be enabled by using the memchr feature.Full Changelog: https://github.com/pest-parser/pest/compare/v2.5.0...v2.5.1
pest_debugger crate (fixes #98) by @dragostis and @tomtau in https://github.com/pest-parser/pest/pull/736
Full Changelog: https://github.com/pest-parser/pest/compare/v2.4.1...v2.5.0
pest_metaWe found out that, in addition to a breaking change in pest that was reverted, there were a few breaking changes in pest_meta in v2.2.0:
pest_meta::validator::validate_undefined now takes 2 parameters instead of 3,pest_meta::validator::validate_pest_keywords now takes 1 parameter instead of 2,pest_meta::validator::validate_rust_keywords now takes 1 parameter instead of 2.Given pest_meta is primarily used within pest's own crates[^1] and no one opened an issue regarding these breaking changes, we decided not to revert the post-2.2.0 releases and keep those functions as they are now in 2.5.0[^2].
Having said that, we now have a CI action to check for semantic versioning, so we should be able to avoid accidental breaking changes in the future.
[^1]: Those three pest_meta functions are rather internal and perhaps did not need to be made public early on.
[^2]: If these accidental pest_meta breaking changes cause any trouble in your code, please feel free to open an issue though!
pest_debugger)While pest's focus is on accessibility, developers can sometimes struggle to understand what is going under the hood and why a particular input is parsed in a particular way (or fails to parse). A long time ago, @dragostis implemented a simple CLI debugger that could help in this aspect, but this effort was not finished. This implementation was revived and you are now welcome to use it. You should be able to install it using:
cargo install pest_debugger
You can then run the interactive debugger by calling pest_debugger and view its help by typing h in its prompt:
> h
Use the following commands:
g <grammar filename> - load .pest grammar
i <input filename> - load input from a file
id <input text> - load input directly from a single-line input
ba - add breakpoints at all rules
b <rule> - add a breakpoint at a rule
d <rule> - delete a breakpoint at a rule
da - delete all breakpoints
r <rule> - run a rule
c - continue
l - list breakpoints
h - help
The commands are self-explanatory; for a quick reference, the basic usage is:
> g ...file path to your grammar...
> i ...file path to your input...
> b ...name of the rule you want to stop at...
> r ...the rule to start running at...
:bulb: There is a tab completion for file paths and command history.
And then, once the debugger hits a breakpoint, you can continue the execution by typing:
> c
:bulb: You can also start up the debugger with command-line arguments that will do those steps during initialisation:
Usage: pest_debugger [options]
Options:
-g, --grammar <grammar file> - load .pest grammar
-i, --input <input file> - load input file
-r, --rule <rule> - run rule
-b, --breakpoint <rule> - breakpoint at rule
-s, --session <session file> - load session history file
-h, --help - print this help menu
If you are using pest in your projects and would like to contribute to its development by organising its issues, reviewing its pull requests etc., please feel free to comment on this post to join the triage team!
In addition to that, here are also a few potential ideas for work that can help anyone who would like to get familiar with pest's implementation:
Does any of these ideas sound interesting to you and would like to work on them? Or do you have other pest-related ideas you are working on or would like to explore? Please don't hesitate to share them in the comments below the announcement!