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13 Commits
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b6c7656194
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IO and redirection overhaul (#11934)
# Description The PR overhauls how IO redirection is handled, allowing more explicit and fine-grain control over `stdout` and `stderr` output as well as more efficient IO and piping. To summarize the changes in this PR: - Added a new `IoStream` type to indicate the intended destination for a pipeline element's `stdout` and `stderr`. - The `stdout` and `stderr` `IoStream`s are stored in the `Stack` and to avoid adding 6 additional arguments to every eval function and `Command::run`. The `stdout` and `stderr` streams can be temporarily overwritten through functions on `Stack` and these functions will return a guard that restores the original `stdout` and `stderr` when dropped. - In the AST, redirections are now directly part of a `PipelineElement` as a `Option<Redirection>` field instead of having multiple different `PipelineElement` enum variants for each kind of redirection. This required changes to the parser, mainly in `lite_parser.rs`. - `Command`s can also set a `IoStream` override/redirection which will apply to the previous command in the pipeline. This is used, for example, in `ignore` to allow the previous external command to have its stdout redirected to `Stdio::null()` at spawn time. In contrast, the current implementation has to create an os pipe and manually consume the output on nushell's side. File and pipe redirections (`o>`, `e>`, `e>|`, etc.) have precedence over overrides from commands. This PR improves piping and IO speed, partially addressing #10763. Using the `throughput` command from that issue, this PR gives the following speedup on my setup for the commands below: | Command | Before (MB/s) | After (MB/s) | Bash (MB/s) | | --------------------------- | -------------:| ------------:| -----------:| | `throughput o> /dev/null` | 1169 | 52938 | 54305 | | `throughput \| ignore` | 840 | 55438 | N/A | | `throughput \| null` | Error | 53617 | N/A | | `throughput \| rg 'x'` | 1165 | 3049 | 3736 | | `(throughput) \| rg 'x'` | 810 | 3085 | 3815 | (Numbers above are the median samples for throughput) This PR also paves the way to refactor our `ExternalStream` handling in the various commands. For example, this PR already fixes the following code: ```nushell ^sh -c 'echo -n "hello "; sleep 0; echo "world"' | find "hello world" ``` This returns an empty list on 0.90.1 and returns a highlighted "hello world" on this PR. Since the `stdout` and `stderr` `IoStream`s are available to commands when they are run, then this unlocks the potential for more convenient behavior. E.g., the `find` command can disable its ansi highlighting if it detects that the output `IoStream` is not the terminal. Knowing the output streams will also allow background job output to be redirected more easily and efficiently. # User-Facing Changes - External commands returned from closures will be collected (in most cases): ```nushell 1..2 | each {|_| nu -c "print a" } ``` This gives `["a", "a"]` on this PR, whereas this used to print "a\na\n" and then return an empty list. ```nushell 1..2 | each {|_| nu -c "print -e a" } ``` This gives `["", ""]` and prints "a\na\n" to stderr, whereas this used to return an empty list and print "a\na\n" to stderr. - Trailing new lines are always trimmed for external commands when piping into internal commands or collecting it as a value. (Failure to decode the output as utf-8 will keep the trailing newline for the last binary value.) In the current nushell version, the following three code snippets differ only in parenthesis placement, but they all also have different outputs: 1. `1..2 | each { ^echo a }` ``` a a ╭────────────╮ │ empty list │ ╰────────────╯ ``` 2. `1..2 | each { (^echo a) }` ``` ╭───┬───╮ │ 0 │ a │ │ 1 │ a │ ╰───┴───╯ ``` 3. `1..2 | (each { ^echo a })` ``` ╭───┬───╮ │ 0 │ a │ │ │ │ │ 1 │ a │ │ │ │ ╰───┴───╯ ``` But in this PR, the above snippets will all have the same output: ``` ╭───┬───╮ │ 0 │ a │ │ 1 │ a │ ╰───┴───╯ ``` - All existing flags on `run-external` are now deprecated. - File redirections now apply to all commands inside a code block: ```nushell (nu -c "print -e a"; nu -c "print -e b") e> test.out ``` This gives "a\nb\n" in `test.out` and prints nothing. The same result would happen when printing to stdout and using a `o>` file redirection. - External command output will (almost) never be ignored, and ignoring output must be explicit now: ```nushell (^echo a; ^echo b) ``` This prints "a\nb\n", whereas this used to print only "b\n". This only applies to external commands; values and internal commands not in return position will not print anything (e.g., `(echo a; echo b)` still only prints "b"). - `complete` now always captures stderr (`do` is not necessary). # After Submitting The language guide and other documentation will need to be updated. |
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14d1c67863
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Debugger experiments (#11441)
<!-- 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. --> This PR adds a new evaluator path with callbacks to a mutable trait object implementing a Debugger trait. The trait object can do anything, e.g., profiling, code coverage, step debugging. Currently, entering/leaving a block and a pipeline element is marked with callbacks, but more callbacks can be added as necessary. Not all callbacks need to be used by all debuggers; unused ones are simply empty calls. A simple profiler is implemented as a proof of concept. The debugging support is implementing by making `eval_xxx()` functions generic depending on whether we're debugging or not. This has zero computational overhead, but makes the binary slightly larger (see benchmarks below). `eval_xxx()` variants called from commands (like `eval_block_with_early_return()` in `each`) are chosen with a dynamic dispatch for two reasons: to not grow the binary size due to duplicating the code of many commands, and for the fact that it isn't possible because it would make Command trait objects object-unsafe. In the future, I hope it will be possible to allow plugin callbacks such that users would be able to implement their profiler plugins instead of having to recompile Nushell. [DAP](https://microsoft.github.io/debug-adapter-protocol/) would also be interesting to explore. Try `help debug profile`. ## Screenshots Basic output:  To profile with more granularity, increase the profiler depth (you'll see that repeated `is-windows` calls take a large chunk of total time, making it a good candidate for optimizing):  ## Benchmarks ### Binary size Binary size increase vs. main: **+40360 bytes**. _(Both built with `--release --features=extra,dataframe`.)_ ### Time ```nushell # bench_debug.nu use std bench let test = { 1..100 | each { ls | each {|row| $row.name | str length } } | flatten | math avg } print 'debug:' let res2 = bench { debug profile $test } --pretty print $res2 ``` ```nushell # bench_nodebug.nu use std bench let test = { 1..100 | each { ls | each {|row| $row.name | str length } } | flatten | math avg } print 'no debug:' let res1 = bench { do $test } --pretty print $res1 ``` `cargo run --release -- bench_debug.nu` is consistently 1--2 ms slower than `cargo run --release -- bench_nodebug.nu` due to the collection overhead + gathering the report. This is expected. When gathering more stuff, the overhead is obviously higher. `cargo run --release -- bench_nodebug.nu` vs. `nu bench_nodebug.nu` I didn't measure any difference. Both benchmarks report times between 97 and 103 ms randomly, without one being consistently higher than the other. This suggests that at least in this particular case, when not running any debugger, there is no runtime overhead. ## API changes This PR adds a generic parameter to all `eval_xxx` functions that forces you to specify whether you use the debugger. You can resolve it in two ways: * Use a provided helper that will figure it out for you. If you wanted to use `eval_block(&engine_state, ...)`, call `let eval_block = get_eval_block(&engine_state); eval_block(&engine_state, ...)` * If you know you're in an evaluation path that doesn't need debugger support, call `eval_block::<WithoutDebug>(&engine_state, ...)` (this is the case of hooks, for example). I tried to add more explanation in the docstring of `debugger_trait.rs`. ## TODO - [x] Better profiler output to reduce spam of iterative commands like `each` - [x] Resolve `TODO: DEBUG` comments - [x] Resolve unwraps - [x] Add doc comments - [x] Add usage and extra usage for `debug profile`, explaining all columns # User-Facing Changes <!-- List of all changes that impact the user experience here. This helps us keep track of breaking changes. --> Hopefully none. # 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 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. --> |
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f7d647ac3c
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open , rm , umv , cp , rm and du : Don't globs if inputs are variables or string interpolation (#11886)
# Description
This is a follow up to
https://github.com/nushell/nushell/pull/11621#issuecomment-1937484322
Also Fixes: #11838
## About the code change
It applys the same logic when we pass variables to external commands:
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fb4251aba7
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Remove Record::from_raw_cols_vals_unchecked (#11810)
# Description Follows from #11718 and replaces all usages of `Record::from_raw_cols_vals_unchecked` with iterator or `record!` equivalents. |
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1c49ca503a
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Name the Value conversion functions more clearly (#11851)
# Description This PR renames the conversion functions on `Value` to be more consistent. It follows the Rust [API guidelines](https://rust-lang.github.io/api-guidelines/naming.html#ad-hoc-conversions-follow-as_-to_-into_-conventions-c-conv) for ad-hoc conversions. The conversion functions on `Value` now come in a few forms: - `coerce_{type}` takes a `&Value` and attempts to convert the value to `type` (e.g., `i64` are converted to `f64`). This is the old behavior of some of the `as_{type}` functions -- these functions have simply been renamed to better reflect what they do. - The new `as_{type}` functions take a `&Value` and returns an `Ok` result only if the value is of `type` (no conversion is attempted). The returned value will be borrowed if `type` is non-`Copy`, otherwise an owned value is returned. - `into_{type}` exists for non-`Copy` types, but otherwise does not attempt conversion just like `as_type`. It takes an owned `Value` and always returns an owned result. - `coerce_into_{type}` has the same relationship with `coerce_{type}` as `into_{type}` does with `as_{type}`. - `to_{kind}_string`: conversion to different string formats (debug, abbreviated, etc.). Only two of the old string conversion functions were removed, the rest have been renamed only. - `to_{type}`: other conversion functions. Currently, only `to_path` exists. (And `to_string` through `Display`.) This table summaries the above: | Form | Cost | Input Ownership | Output Ownership | Converts `Value` case/`type` | | ---------------------------- | ----- | --------------- | ---------------- | -------- | | `as_{type}` | Cheap | Borrowed | Borrowed/Owned | No | | `into_{type}` | Cheap | Owned | Owned | No | | `coerce_{type}` | Cheap | Borrowed | Borrowed/Owned | Yes | | `coerce_into_{type}` | Cheap | Owned | Owned | Yes | | `to_{kind}_string` | Expensive | Borrowed | Owned | Yes | | `to_{type}` | Expensive | Borrowed | Owned | Yes | # User-Facing Changes Breaking API change for `Value` in `nu-protocol` which is exposed as part of the plugin API. |
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b8d37a7541
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Fix panic in rotate ; Add safe record creation function (#11718)
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# 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.
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Fixes https://github.com/nushell/nushell/issues/11716
The problem is in our [record creation
API](
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d646903161
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Unify glob behavior on open , rm , cp-old , mv , umv , cp and du commands (#11621)
# Description This pr is a follow up to [#11569](https://github.com/nushell/nushell/pull/11569#issuecomment-1902279587) > Revert the logic in https://github.com/nushell/nushell/pull/10694 and apply the logic in this pr to mv, cp, rv will require a larger change, I need to think how to achieve the bahavior And sorry @bobhy for reverting some of your changes. This pr is going to unify glob behavior on the given commands: * open * rm * cp-old * mv * umv * cp * du So they have the same behavior to `ls`, which is: If given parameter is quoted by single quote(`'`) or double quote(`"`), don't auto-expand the glob pattern. If not quoted, auto-expand the glob pattern. Fixes: #9558 Fixes: #10211 Fixes: #9310 Fixes: #10364 # TODO But there is one thing remains: if we give a variable to the command, it will always auto-expand the glob pattern, e.g: ```nushell let path = "a[123]b" rm $path ``` I don't think it's expected. But I also think user might want to auto-expand the glob pattern in variables. So I'll introduce a new command called `glob escape`, then if user doesn't want to auto-expand the glob pattern, he can just do this: `rm ($path | glob escape)` # User-Facing Changes <!-- List of all changes that impact the user experience here. This helps us keep track of breaking changes. --> # Tests + Formatting Done # 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. --> ## NOTE This pr changes the semantic of `GlobPattern`, before this pr, it will `expand path` after evaluated, this makes `nu_engine::glob_from` have no chance to glob things right if a path contains glob pattern. e.g: [#9310 ](https://github.com/nushell/nushell/issues/9310#issuecomment-1886824030) #10211 I think changing the semantic is fine, because it makes glob works if path contains something like '*'. It maybe a breaking change if a custom command's argument are annotated by `: glob`. |
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90d65bb987
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Evaluate string interpolation at parse time (#11562)
<!-- 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! --> Closes #11561 # 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 allow string interpolation at parse time. Since the actual config hasn't been loaded at parse time, this uses the `get_config()` method on `StateWorkingSet`. So file sizes and datetimes (I think those are the only things whose string representations depend on the config) may be formatted differently from how users have configured things, which may come as a surprise to some. It does seem unlikely that anyone would be formatting file sizes or date times at parse time. Still, something to think about if/before this PR merged. Also, I changed the `ModuleNotFound` error to include the name of the module. # User-Facing Changes <!-- List of all changes that impact the user experience here. This helps us keep track of breaking changes. --> Users will be able to do stuff like: ```nu const x = [1 2 3] const y = $"foo($x)" // foo[1, 2, 3] ``` The main use case is `use`-ing and `source`-ing files at parse time: ```nu const file = "foo.nu" use $"($file)" ``` If the module isn't found, you'll see an error like this: ``` Error: nu::parser::module_not_found × Module not found. ╭─[entry #3:1:1] 1 │ use $"($file)" · ─────┬──── · ╰── module foo.nu not found ╰──── help: module files and their paths must be available before your script is run as parsing occurs before anything is evaluated ``` # 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 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. --> Although there's user-facing changes, there's probably no need to change the docs since people probably already expect string interpolation to work at parse time. Edit: @kubouch pointed out that we'd need to document the fact that stuff like file sizes and datetimes won't get formatted according to user's runtime configs, so I'll make a PR to nushell.github.io after this one |
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c59d6d31bc
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do not attempt to glob expand if the file path is wrapped in quotes (#11569)
# Description Fixes: #11455 ### For arguments which is annotated with `:path/:directory/:glob` To fix the issue, we need to have a way to know if a path is originally quoted during runtime. So the information needed to be added at several levels: * parse time (from user input to expression) We need to add quoted information into `Expr::Filepath`, `Expr::Directory`, `Expr::GlobPattern` * eval time When convert from `Expr::Filepath`, `Expr::Directory`, `Expr::GlobPattern` to `Value::String` during runtime, we won't auto expanded the path if it's quoted ### For `ls` It's really special, because it accepts a `String` as a pattern, and it generates `glob` expression inside the command itself. So the idea behind the change is introducing a special SyntaxShape to ls: `SyntaxShape::LsGlobPattern`. So we can track if the pattern is originally quoted easier, and we don't auto expand the path either. Then when constructing a glob pattern inside ls, we check if input pattern is quoted, if so: we escape the input pattern, so we can run `ls a[123]b`, because it's already escaped. Finally, to accomplish the checking process, we also need to introduce a new value type called `Value::QuotedString` to differ from `Value::String`, it's used to generate an enum called `NuPath`, which is finally used in `ls` function. `ls` learned from `NuPath` to know if user input is quoted. # User-Facing Changes Actually it contains several changes ### For arguments which is annotated with `:path/:directory/:glob` #### Before ```nushell > def foo [p: path] { echo $p }; print (foo "~/a"); print (foo '~/a') /home/windsoilder/a /home/windsoilder/a > def foo [p: directory] { echo $p }; print (foo "~/a"); print (foo '~/a') /home/windsoilder/a /home/windsoilder/a > def foo [p: glob] { echo $p }; print (foo "~/a"); print (foo '~/a') /home/windsoilder/a /home/windsoilder/a ``` #### After ```nushell > def foo [p: path] { echo $p }; print (foo "~/a"); print (foo '~/a') ~/a ~/a > def foo [p: directory] { echo $p }; print (foo "~/a"); print (foo '~/a') ~/a ~/a > def foo [p: glob] { echo $p }; print (foo "~/a"); print (foo '~/a') ~/a ~/a ``` ### For ls command `touch '[uwu]'` #### Before ``` ❯ ls -D "[uwu]" Error: × No matches found for [uwu] ╭─[entry #6:1:1] 1 │ ls -D "[uwu]" · ───┬─── · ╰── Pattern, file or folder not found ╰──── help: no matches found ``` #### After ``` ❯ ls -D "[uwu]" ╭───┬───────┬──────┬──────┬──────────╮ │ # │ name │ type │ size │ modified │ ├───┼───────┼──────┼──────┼──────────┤ │ 0 │ [uwu] │ file │ 0 B │ now │ ╰───┴───────┴──────┴──────┴──────────╯ ``` # Tests + Formatting Done # After Submitting NaN |
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21b3eeed99
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Allow spreading arguments to commands (#11289)
<!-- 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! --> Finishes implementing https://github.com/nushell/nushell/issues/10598, which asks for a spread operator in lists, in records, and when calling commands. # 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 allow spreading arguments to commands (both internal and external). It will also deprecate spreading arguments automatically when passing to external commands. # User-Facing Changes <!-- List of all changes that impact the user experience here. This helps us keep track of breaking changes. --> - Users will be able to use `...` to spread arguments to custom/builtin commands that have rest parameters or allow unknown arguments, or to any external command - If a custom command doesn't have a rest parameter and it doesn't allow unknown arguments either, the spread operator will not be allowed - Passing lists to external commands without `...` will work for now but will cause a deprecation warning saying that it'll stop working in 0.91 (is 2 versions enough time?) Here's a function to help with demonstrating some behavior: ```nushell > def foo [ a, b, c?, d?, ...rest ] { [$a $b $c $d $rest] | to nuon } ``` You can pass a list of arguments to fill in the `rest` parameter using `...`: ```nushell > foo 1 2 3 4 ...[5 6] [1, 2, 3, 4, [5, 6]] ``` If you don't use `...`, the list `[5 6]` will be treated as a single argument: ```nushell > foo 1 2 3 4 [5 6] # Note the double [[]] [1, 2, 3, 4, [[5, 6]]] ``` You can omit optional parameters before the spread arguments: ```nushell > foo 1 2 3 ...[4 5] # d is omitted here [1, 2, 3, null, [4, 5]] ``` If you have multiple lists, you can spread them all: ```nushell > foo 1 2 3 ...[4 5] 6 7 ...[8] ...[] [1, 2, 3, null, [4, 5, 6, 7, 8]] ``` Here's the kind of error you get when you try to spread arguments to a command with no rest parameter:  And this is the warning you get when you pass a list to an external now (without `...`):  # 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 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 > ``` --> Added tests to cover the following cases: - Spreading arguments to a command that doesn't have a rest parameter (unexpected spread argument error) - Spreading arguments to a command that doesn't have a rest parameter *but* there's also a missing positional argument (missing positional error) - Spreading arguments to a command that doesn't have a rest parameter but does allow unknown arguments, such as `exec` (allowed) - Spreading a list literal containing arguments of the wrong type (parse error) - Spreading a non-list value, both to internal and external commands - Having named arguments in the middle of rest arguments - `explain`ing a command call that spreads its arguments # 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. --> # Examples Suppose you have multiple tables: ```nushell let people = [[id name age]; [0 alice 100] [1 bob 200] [2 eve 300]] let evil_twins = [[id name age]; [0 ecila 100] [-1 bob 200] [-2 eve 300]] ``` Maybe you often find yourself needing to merge multiple tables and want a utility to do that. You could write a function like this: ```nushell def merge_all [ ...tables ] { $tables | reduce { |it, acc| $acc | merge $it } } ``` Then you can use it like this: ```nushell > merge_all ...([$people $evil_twins] | each { |$it| $it | select name age }) ╭───┬───────┬─────╮ │ # │ name │ age │ ├───┼───────┼─────┤ │ 0 │ ecila │ 100 │ │ 1 │ bob │ 200 │ │ 2 │ eve │ 300 │ ╰───┴───────┴─────╯ ``` Except they had duplicate columns, so now you first want to suffix every column with a number to tell you which table the column came from. You can make a command for that: ```nushell def select_and_merge [ --cols: list<string>, ...tables ] { let renamed_tables = $tables | enumerate | each { |it| $it.item | select $cols | rename ...($cols | each { |col| $col + ($it.index | into string) }) }; merge_all ...$renamed_tables } ``` And call it like this: ```nushell > select_and_merge --cols [name age] $people $evil_twins ╭───┬───────┬──────┬───────┬──────╮ │ # │ name0 │ age0 │ name1 │ age1 │ ├───┼───────┼──────┼───────┼──────┤ │ 0 │ alice │ 100 │ ecila │ 100 │ │ 1 │ bob │ 200 │ bob │ 200 │ │ 2 │ eve │ 300 │ eve │ 300 │ ╰───┴───────┴──────┴───────┴──────╯ ``` --- Suppose someone's made a command to search for APT packages: ```nushell # The main command def search-pkgs [ --install # Whether to install any packages it finds log_level: int # Pretend it's a good idea to make this a required positional parameter exclude?: list<string> # Packages to exclude repositories?: list<string> # Which repositories to look in (searches in all if not given) ...pkgs # Package names to search for ] { { install: $install, log_level: $log_level, exclude: ($exclude | to nuon), repositories: ($repositories | to nuon), pkgs: ($pkgs | to nuon) } } ``` It has a lot of parameters to configure it, so you might make your own helper commands to wrap around it for specific cases. Here's one example: ```nushell # Only look for packages locally def search-pkgs-local [ --install # Whether to install any packages it finds log_level: int exclude?: list<string> # Packages to exclude ...pkgs # Package names to search for ] { # All required and optional positional parameters are given search-pkgs --install=$install $log_level [] ["<local URI or something>"] ...$pkgs } ``` And you can run it like this: ```nushell > search-pkgs-local --install=false 5 ...["python2.7" "vim"] ╭──────────────┬──────────────────────────────╮ │ install │ false │ │ log_level │ 5 │ │ exclude │ [] │ │ repositories │ ["<local URI or something>"] │ │ pkgs │ ["python2.7", vim] │ ╰──────────────┴──────────────────────────────╯ ``` One thing I realized when writing this was that if we decide to not allow passing optional arguments using the spread operator, then you can (mis?)use the spread operator to skip optional parameters. Here, I didn't want to give `exclude` explicitly, so I used a spread operator to pass the packages to install. Without it, I would've needed to do `search-pkgs-local --install=false 5 [] "python2.7" "vim"` (explicitly pass `[]` (or `null`, in the general case) to `exclude`). There are probably more idiomatic ways to do this, but I just thought it was something interesting. If you're a virologist of the [xkcd](https://xkcd.com/350/) kind, another helper command you might make is this: ```nushell # Install any packages it finds def live-dangerously [ ...pkgs ] { # One optional argument was given (exclude), while another was not (repositories) search-pkgs 0 [] ...$pkgs --install # Flags can go after spread arguments } ``` Running it: ```nushell > live-dangerously "git" "*vi*" # *vi* because I don't feel like typing out vim and neovim ╭──────────────┬─────────────╮ │ install │ true │ │ log_level │ 0 │ │ exclude │ [] │ │ repositories │ null │ │ pkgs │ [git, *vi*] │ ╰──────────────┴─────────────╯ ``` Here's an example that uses the spread operator more than once within the same command call: ```nushell let extras = [ chrome firefox python java git ] def search-pkgs-curated [ ...pkgs ] { (search-pkgs 1 [emacs] ["example.com", "foo.com"] vim # A must for everyone! ...($pkgs | filter { |p| not ($p | str contains "*") }) # Remove packages with globs python # Good tool to have ...$extras --install=false python3) # I forget, did I already put Python in extras? } ``` Running it: ```nushell > search-pkgs-curated "git" "*vi*" ╭──────────────┬───────────────────────────────────────────────────────────────────╮ │ install │ false │ │ log_level │ 1 │ │ exclude │ [emacs] │ │ repositories │ [example.com, foo.com] │ │ pkgs │ [vim, git, python, chrome, firefox, python, java, git, "python3"] │ ╰──────────────┴───────────────────────────────────────────────────────────────────╯ ``` |
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ff6a67d293
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Remove Expr::MatchPattern (#11367)
# Description Following from #11356, it looks like `Expr::MatchPattern` is no longer used in any way. This PR removes `Expr::MatchPattern` alongside `Type::MatchPattern` and `SyntaxShape::MatchPattern`. # User-Facing Changes Breaking API change for `nu_protocol`. |
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c9c93f5b4d
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Remove Value::MatchPattern (#11356)
# Description `Value::MatchPattern` implies that `MatchPattern`s are first-class values. This PR removes this case, and commands must now instead use `Expr::MatchPattern` to extract `MatchPattern`s just like how the `match` command does using `Expr::MatchBlock`. # User-Facing Changes Breaking API change for `nu_protocol` crate. |
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c1a30ac60f
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Reduce code duplication in eval.rs and eval_const.rs (#11192) |