nushell/src
JT 5d9e2455f7
Let with pipeline (#9589)
# Description

This changes the default behaviour of `let` to be able to take a
pipeline as its initial value.

For example:

```
> let x = "hello world" | str length
```

This is a change from the existing behaviour, where the right hand side
is assumed to be an expression. Pipelines are more general, and can be
more powerful.

My google foo is failing me, but this also fixes this issue:

```
let x = foo
```

Currently, this reads `foo` as a bareword that gets converted to a
string rather than running the `foo` command. In practice, this is
really annoying and is a really hard to spot bug in a script.

# User-Facing Changes

BREAKING CHANGE BREAKING CHANGE

`let` gains the power to be assigned via a pipeline. However, this
changes the behaviour of `let x = foo` from assigning the string "foo"
to `$x` to being "run the command `foo` and give the result to `$x`"

# 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 -A
clippy::needless_collect -A clippy::result_large_err` to check that
you're using the standard code style
- `cargo test --workspace` to check that all tests pass
- `cargo run -- crates/nu-std/tests/run.nu` 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.
-->
2023-07-03 17:45:10 +12:00
..
tests Let with pipeline (#9589) 2023-07-03 17:45:10 +12:00
command.rs update ide-check help text (#9559) 2023-06-29 11:40:52 -05:00
config_files.rs remove let-env, focus on mutating $env (#9574) 2023-07-01 07:57:51 +12:00
ide.rs add --ide-ast for a simplistic ast for editors (#8995) 2023-04-28 08:51:51 -05:00
logger.rs Use variable names directly in the format strings (#7906) 2023-01-29 19:37:54 -06:00
main.rs cratification: move the bytes command to nu-cmd-extra (#9509) 2023-06-23 12:23:08 -07:00
README.md Remove old nushell/merge engine-q 2022-02-07 14:54:06 -05:00
run.rs if --no-config-file(-n) is passed, do not load config files with -c (#9286) 2023-05-25 08:24:56 -05:00
signals.rs Cleanup of src/main.rs (#7801) 2023-01-20 10:44:49 -08:00
terminal.rs Move all functions of main.rs into modules (#7803) 2023-01-20 13:20:38 -08:00
test_bins.rs Break up interdependencies of command crates (#9429) 2023-06-14 23:12:55 +02:00
tests.rs nu-cmd-extra crate infrastructure in place with the Bits command as the model for adding other commands (#9327) 2023-06-01 10:46:16 -07:00

Nushell REPL

This directory contains the main Nushell REPL (read eval print loop) as part of the CLI portion of Nushell, which creates the nu binary itself.

Current versions of the nu binary will use the Nu argument parsing logic to parse the commandline arguments passed to nu, leaving the logic here to be a thin layer around what the core libraries.