nushell/crates
Andreas Källberg 6df001f72d
Prevent cubic time on nested parentheses (#10467)
<!--
if this PR closes one or more issues, you can automatically link the PR
with
them by using one of the [*linking
keywords*](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword),
e.g.
- this PR should close #xxxx
- fixes #xxxx

you can also mention related issues, PRs or discussions!
-->

# Description
<!--
Thank you for improving Nushell. Please, check our [contributing
guide](../CONTRIBUTING.md) and talk to the core team before making major
changes.

Description of your pull request goes here. **Provide examples and/or
screenshots** if your changes affect the user experience.
-->

When parse_range get an item like ((((1..2)))) it would try to parse
"((((1" with a long chain of recursive parsers, namely:
- parse_value
- parse_paren_expr
- parse_full_cell_path
- parse_block
- parse_pipeline
- parse_builtin_commands
- parse_expression
- parse_math_expression
- parse_value
- ...

where `parse_paren_expr` calls `parse_range` in turn. Because at any
time in the chain `parse_paren_expr` can call `parse_range`, which will
then continue the chain, we get quadratic number of function calls, each
linear on the size of the input

By checking with the lexer that the parens are matched, we prevent the
long chain from being called on unmatched braces. Now, this is still
more quadratic than it needs to be, to fix that, we should process
parens only once, instead of on each recursive call

# User-Facing Changes
<!-- List of all changes that impact the user experience here. This
helps us keep track of breaking changes. -->
Speed improvements in some edge cases

# Tests + Formatting
Not sure how to test this, maybe I could add a benchmark
<!--
Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used` to
check that you're using the standard code style
- `cargo test --workspace` to check that all tests pass (on Windows make
sure to [enable developer
mode](https://learn.microsoft.com/en-us/windows/apps/get-started/developer-mode-features-and-debugging))
- `cargo run -- -c "use std testing; testing run-tests --path
crates/nu-std"` to run the tests for the standard library

> **Note**
> from `nushell` you can also use the `toolkit` as follows
> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```
-->

# After Submitting
<!-- If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
-->

# Other notes
Found using the fuzzer, by setting a timeout on max run-time. It also
found a stack-overflow on too many parentheses, which this doesn't fix.
2023-09-23 04:24:35 +12:00
..
nu_plugin_custom_values Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu_plugin_example Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu_plugin_formats Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu_plugin_gstat Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu_plugin_inc Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu_plugin_python remove vectorize_over_list from python plugin (#9905) 2023-08-03 16:46:48 +02:00
nu_plugin_query Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-cli Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-cmd-base Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-cmd-dataframe Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-cmd-extra Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-cmd-lang Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-color-config Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-command Improve select row perf for large N (#10355) 2023-09-21 23:51:13 +02:00
nu-engine Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-explore Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-glob Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-json Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-parser Prevent cubic time on nested parentheses (#10467) 2023-09-23 04:24:35 +12:00
nu-path Fix tilde-expansion for multi-byte unicode chars (#10434) 2023-09-21 04:04:28 +12:00
nu-plugin Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-pretty-hex Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-protocol Split up nu-protocol/src/engine/engine_state.rs (#10368) 2023-09-21 22:53:36 +02:00
nu-std Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-system Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-table Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-term-grid Bump to 0.85.1 development version (#10431) 2023-09-20 18:38:42 +12:00
nu-test-support Simplify nu! test macros. (#10403) 2023-09-21 20:11:56 +02:00
nu-utils nu-table: Add table option --abbreviated (#10399) 2023-09-20 12:59:08 -05:00
README.md Remove old nushell/merge engine-q 2022-02-07 14:54:06 -05:00

Nushell core libraries and plugins

These sub-crates form both the foundation for Nu and a set of plugins which extend Nu with additional functionality.

Foundational libraries are split into two kinds of crates:

  • Core crates - those crates that work together to build the Nushell language engine
  • Support crates - a set of crates that support the engine with additional features like JSON support, ANSI support, and more.

Plugins are likewise also split into two types:

  • Core plugins - plugins that provide part of the default experience of Nu, including access to the system properties, processes, and web-connectivity features.
  • Extra plugins - these plugins run a wide range of different capabilities like working with different file types, charting, viewing binary data, and more.