nushell/crates/nu-std
Bahex 301d1370c4
Add input support to generate (#14804)
- closes #8523 

# Description

This PR adds pipeline input support to `generate`.
- Without input, `generate` keeps its current behavior.
- With input, each invocation of the closure is provided an item from
the input stream as pipeline input (`$in`). If/when the input stream
runs out, `generate` also stops.

Before this PR, there is no filter command that is both stateful _and_
streaming.

This PR also refactors `std/iter scan` to use `generate`, making it
streaming and more performant over larger inputs.

# User-Facing Changes
- `generate` now supports pipeline input, passing each element to the
closure as `$in` until it runs out
- `std/iter scan` is now streaming

# Tests + Formatting
Added tests to validate the new feature.

- 🟢 toolkit fmt
- 🟢 toolkit clippy
- 🟢 toolkit test
- 🟢 toolkit test stdlib

# After Submitting
N/A
2025-01-14 11:44:31 -06:00
..
src Always load default env/config values (#14249) 2024-11-20 16:15:15 -06:00
std Add input support to generate (#14804) 2025-01-14 11:44:31 -06:00
tests Add run-time type checking for command pipeline input (#14741) 2025-01-08 23:09:47 +01:00
Cargo.toml Bump version to 0.101.1 (#14661) 2024-12-24 23:47:00 +01:00
CONTRIBUTING.md Surprising symlink resolution for std path add (#13258) 2024-06-28 18:11:48 -05:00
LICENSE add LICENSE to nu-std (#8803) 2023-04-07 13:39:21 -07:00
README.md Change the usage misnomer to "description" (#13598) 2024-08-22 12:02:08 +02:00
testing.nu Add run-time type checking for command pipeline input (#14741) 2025-01-08 23:09:47 +01:00

Welcome to the standard library of `nushell`!

The standard library is a pure-nushell collection of custom commands which provide interactive utilities and building blocks for users writing casual scripts or complex applications.

To see what's here:

> use std
> scope commands | select name description | where name =~ "std "
#┬───────────name────────────┬───────────────────description───────────────────
0│std assert                 │Universal assert command
1│std assert equal           │Assert $left == $right
2│std assert error           │Assert that executing the code generates an error
3│std assert greater         │Assert $left > $right
4│std assert greater or equal│Assert $left >= $right
             ...                                     ...
─┴───────────────────────────┴─────────────────────────────────────────────────

🧰 Using the standard library in the REPL or in scripts

All commands in the standard library must be "imported" into the running environment (the interactive read-execute-print-loop (REPL) or a .nu script) using the use command.

You can choose to import the whole module, but then must refer to individual commands with a std prefix, e.g:

use std

std log debug "Running now"
std assert (1 == 2)

Or you can enumerate the specific commands you want to import and invoke them without the std prefix.

use std ["log debug" assert]

log debug "Running again"
assert (2 == 1)

This is probably the form of import you'll want to add to your env.nu for interactive use.

✏️ contribute to the standard library

You're invited to contribute to the standard library! See CONTRIBUTING.md for details