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5 Commits
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d7392f1f3b
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Internal representation (IR) compiler and evaluator (#13330)
# Description This PR adds an internal representation language to Nushell, offering an alternative evaluator based on simple instructions, stream-containing registers, and indexed control flow. The number of registers required is determined statically at compile-time, and the fixed size required is allocated upon entering the block. Each instruction is associated with a span, which makes going backwards from IR instructions to source code very easy. Motivations for IR: 1. **Performance.** By simplifying the evaluation path and making it more cache-friendly and branch predictor-friendly, code that does a lot of computation in Nushell itself can be sped up a decent bit. Because the IR is fairly easy to reason about, we can also implement optimization passes in the future to eliminate and simplify code. 2. **Correctness.** The instructions mostly have very simple and easily-specified behavior, so hopefully engine changes are a little bit easier to reason about, and they can be specified in a more formal way at some point. I have made an effort to document each of the instructions in the docs for the enum itself in a reasonably specific way. Some of the errors that would have happened during evaluation before are now moved to the compilation step instead, because they don't make sense to check during evaluation. 3. **As an intermediate target.** This is a good step for us to bring the [`new-nu-parser`](https://github.com/nushell/new-nu-parser) in at some point, as code generated from new AST can be directly compared to code generated from old AST. If the IR code is functionally equivalent, it will behave the exact same way. 4. **Debugging.** With a little bit more work, we can probably give control over advancing the virtual machine that `IrBlock`s run on to some sort of external driver, making things like breakpoints and single stepping possible. Tools like `view ir` and [`explore ir`](https://github.com/devyn/nu_plugin_explore_ir) make it easier than before to see what exactly is going on with your Nushell code. The goal is to eventually replace the AST evaluator entirely, once we're sure it's working just as well. You can help dogfood this by running Nushell with `$env.NU_USE_IR` set to some value. The environment variable is checked when Nushell starts, so config runs with IR, or it can also be set on a line at the REPL to change it dynamically. It is also checked when running `do` in case within a script you want to just run a specific piece of code with or without IR. # Example ```nushell view ir { |data| mut sum = 0 for n in $data { $sum += $n } $sum } ``` ```gas # 3 registers, 19 instructions, 0 bytes of data 0: load-literal %0, int(0) 1: store-variable var 904, %0 # let 2: drain %0 3: drop %0 4: load-variable %1, var 903 5: iterate %0, %1, end 15 # for, label(1), from(14:) 6: store-variable var 905, %0 7: load-variable %0, var 904 8: load-variable %2, var 905 9: binary-op %0, Math(Plus), %2 10: span %0 11: store-variable var 904, %0 12: load-literal %0, nothing 13: drain %0 14: jump 5 15: drop %0 # label(0), from(5:) 16: drain %0 17: load-variable %0, var 904 18: return %0 ``` # Benchmarks All benchmarks run on a base model Mac Mini M1. ## Iterative Fibonacci sequence This is about as best case as possible, making use of the much faster control flow. Most code will not experience a speed improvement nearly this large. ```nushell def fib [n: int] { mut a = 0 mut b = 1 for _ in 2..=$n { let c = $a + $b $a = $b $b = $c } $b } use std bench bench { 0..50 | each { |n| fib $n } } ``` IR disabled: ``` ╭───────┬─────────────────╮ │ mean │ 1ms 924µs 665ns │ │ min │ 1ms 700µs 83ns │ │ max │ 3ms 450µs 125ns │ │ std │ 395µs 759ns │ │ times │ [list 50 items] │ ╰───────┴─────────────────╯ ``` IR enabled: ``` ╭───────┬─────────────────╮ │ mean │ 452µs 820ns │ │ min │ 427µs 417ns │ │ max │ 540µs 167ns │ │ std │ 17µs 158ns │ │ times │ [list 50 items] │ ╰───────┴─────────────────╯ ```  ## [gradient_benchmark_no_check.nu](https://github.com/nushell/nu_scripts/blob/main/benchmarks/gradient_benchmark_no_check.nu) IR disabled: ``` ╭───┬──────────────────╮ │ 0 │ 27ms 929µs 958ns │ │ 1 │ 21ms 153µs 459ns │ │ 2 │ 18ms 639µs 666ns │ │ 3 │ 19ms 554µs 583ns │ │ 4 │ 13ms 383µs 375ns │ │ 5 │ 11ms 328µs 208ns │ │ 6 │ 5ms 659µs 542ns │ ╰───┴──────────────────╯ ``` IR enabled: ``` ╭───┬──────────────────╮ │ 0 │ 22ms 662µs │ │ 1 │ 17ms 221µs 792ns │ │ 2 │ 14ms 786µs 708ns │ │ 3 │ 13ms 876µs 834ns │ │ 4 │ 13ms 52µs 875ns │ │ 5 │ 11ms 269µs 666ns │ │ 6 │ 6ms 942µs 500ns │ ╰───┴──────────────────╯ ``` ## [random-bytes.nu](https://github.com/nushell/nu_scripts/blob/main/benchmarks/random-bytes.nu) I got pretty random results out of this benchmark so I decided not to include it. Not clear why. # User-Facing Changes - IR compilation errors may appear even if the user isn't evaluating with IR. - IR evaluation can be enabled by setting the `NU_USE_IR` environment variable to any value. - New command `view ir` pretty-prints the IR for a block, and `view ir --json` can be piped into an external tool like [`explore ir`](https://github.com/devyn/nu_plugin_explore_ir). # Tests + Formatting All tests are passing with `NU_USE_IR=1`, and I've added some more eval tests to compare the results for some very core operations. I will probably want to add some more so we don't have to always check `NU_USE_IR=1 toolkit test --workspace` on a regular basis. # After Submitting - [ ] release notes - [ ] further documentation of instructions? - [ ] post-release: publish `nu_plugin_explore_ir` |
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96493b26d9
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Make string related commands parse-time evaluatable (#13032)
<!-- 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! --> Related meta-issue: #10239. # 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. --> This PR will modify some `str`-related commands so that they can be evaluated at parse time. See the following list for those implemented by this pr. # User-Facing Changes <!-- List of all changes that impact the user experience here. This helps us keep track of breaking changes. --> Available now: - `str` subcommands - `trim` - `contains` - `distance` - `ends-with` - `expand` - `index-of` - `join` - `replace` - `reverse` - `starts-with` - `stats` - `substring` - `capitalize` - `downcase` - `upcase` - `split` subcommands - `chars` - `column` - `list` - `row` - `words` - `format` subcommands - `date` - `duration` - `filesize` - string related commands - `parse` - `detect columns` - `encode` & `decode` # Tests + Formatting <!-- 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 toolkit.nu; toolkit test stdlib"` 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 > ``` --> Unresolved questions: - [ ] Is there any routine of testing const expressions? I haven't found any yet. - [ ] Is const expressions required to behave just like there non-const version, like what rust promises? # 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. --> Unresolved questions: - [ ] Do const commands need special marks in the docs? |
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c61075e20e
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Add string/binary type color to ByteStream (#12897)
# Description This PR allows byte streams to optionally be colored as being specifically binary or string data, which guarantees that they'll be converted to `Binary` or `String` appropriately on `into_value()`, making them compatible with `Type` guarantees. This makes them significantly more broadly usable for command input and output. There is still an `Unknown` type for byte streams coming from external commands, which uses the same behavior as we previously did where it's a string if it's UTF-8. A small number of commands were updated to take advantage of this, just to prove the point. I will be adding more after this merges. # User-Facing Changes - New types in `describe`: `string (stream)`, `binary (stream)` - These commands now return a stream if their input was a stream: - `into binary` - `into string` - `bytes collect` - `str join` - `first` (binary) - `last` (binary) - `take` (binary) - `skip` (binary) - Streams that are explicitly binary colored will print as a streaming hexdump - example: ```nushell 1.. | each { into binary } | bytes collect ``` # Tests + Formatting I've added some tests to cover it at a basic level, and it doesn't break anything existing, but I do think more would be nice. Some of those will come when I modify more commands to stream. # After Submitting There are a few things I'm not quite satisfied with: - **String trimming behavior.** We automatically trim newlines from streams from external commands, but I don't think we should do this with internal commands. If I call a command that happens to turn my string into a stream, I don't want the newline to suddenly disappear. I changed this to specifically do it only on `Child` and `File`, but I don't know if this is quite right, and maybe we should bring back the old flag for `trim_end_newline` - **Known binary always resulting in a hexdump.** It would be nice to have a `print --raw`, so that we can put binary data on stdout explicitly if we want to. This PR doesn't change how external commands work though - they still dump straight to stdout. Otherwise, here's the normal checklist: - [ ] release notes - [ ] docs update for plugin protocol changes (added `type` field) --------- Co-authored-by: Ian Manske <ian.manske@pm.me> |
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5c7f7883c8
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Add ErrSpan extension trait for Result (#12626)
# Description This adds an extension trait to `Result` that wraps errors in `Spanned`, saving the effort of calling `.map_err(|err| err.into_spanned(span))` every time. This will hopefully make it even more likely that someone will want to use a spanned `io::Error` and make it easier to remove the impl for `From<io::Error> for ShellError` because that doesn't have span information. |
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c747ec75c9
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Add command_prelude module (#12291)
# Description When implementing a `Command`, one must also import all the types present in the function signatures for `Command`. This makes it so that we often import the same set of types in each command implementation file. E.g., something like this: ```rust use nu_protocol::ast::Call; use nu_protocol::engine::{Command, EngineState, Stack}; use nu_protocol::{ record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, PipelineData, ShellError, Signature, Span, Type, Value, }; ``` This PR adds the `nu_engine::command_prelude` module which contains the necessary and commonly used types to implement a `Command`: ```rust // command_prelude.rs pub use crate::CallExt; pub use nu_protocol::{ ast::{Call, CellPath}, engine::{Command, EngineState, Stack}, record, Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, IntoSpanned, PipelineData, Record, ShellError, Signature, Span, Spanned, SyntaxShape, Type, Value, }; ``` This should reduce the boilerplate needed to implement a command and also gives us a place to track the breadth of the `Command` API. I tried to be conservative with what went into the prelude modules, since it might be hard/annoying to remove items from the prelude in the future. Let me know if something should be included or excluded. |