nushell/crates/nu-std
Ian Manske 1038c64f80
Add sys subcommands (#12747)
# Description
Adds subcommands to `sys` corresponding to each column of the record
returned by `sys`. This is to alleviate the fact that `sys` now returns
a regular record, meaning that it must compute every column which might
take a noticeable amount of time. The subcommands, on the other hand,
only need to compute and return a subset of the data which should be
much faster. In fact, it should be as fast as before, since this is how
the lazy record worked (it would compute only each column as necessary).

I choose to add subcommands instead of having an optional cell-path
parameter on `sys`, since the cell-path parameter would:
- increase the code complexity (can access any value at any row or
nested column)
- prevents discovery with tab-completion
- hinders type checking and allows users to pass potentially invalid
columns

# User-Facing Changes
Deprecates `sys` in favor of the new `sys` subcommands.
2024-05-06 23:20:27 +00:00
..
src Migrate to a new PWD API (#12603) 2024-05-03 14:33:09 +03:00
std Add sys subcommands (#12747) 2024-05-06 23:20:27 +00:00
tests Improve with-env robustness (#12523) 2024-04-16 19:08:58 +08:00
Cargo.toml Bump version to 0.93.1 (#12710) 2024-05-01 17:19:20 -05:00
CONTRIBUTING.md Minimize future false positive typos (#12751) 2024-05-04 15:00:44 +00:00
LICENSE add LICENSE to nu-std (#8803) 2023-04-07 13:39:21 -07:00
README.md fix nu-std README (#11244) 2023-12-06 16:26:02 +01:00
testing.nu Add sys subcommands (#12747) 2024-05-06 23:20:27 +00:00

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 usage | where name =~ "std "
#┬───────────name────────────┬──────────────────────usage──────────────────────
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