nushell/crates/nu-command/tests/commands/mod.rs
Andrés N. Robalino 7a77910720
Table content rolling. (#3097)
There are many use cases. Here we introduce the following:

- The rows can be rolled `... | roll` (up) or `... | roll down`
- Columns can be rolled too (the default is on the `left`, you can pass `... | roll column --opposite` to roll in the other direction)
- You can `roll` the cells of a table and keeping the header names in the same order (`... | roll column --cells-only`)
- Above examples can also be passed (Ex. `... | roll down 3`) a number to tell how many places to roll.

Basic working example with rolling columns:

```
> echo '00000100'
| split chars
| each { str to-int }
| rotate counter-clockwise _
| reject _
| rename bit1 bit2 bit3 bit4 bit5 bit6 bit7 bit8

───┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────
 # │ bit1 │ bit2 │ bit3 │ bit4 │ bit5 │ bit6 │ bit7 │ bit8
───┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────
 0 │    0 │    0 │    0 │    0 │    0 │    1 │    0 │    0
───┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────
```

We want to "shift" three bits to the left of the bitstring (four in decimal), let's try it:

```
> echo '00000100'
| split chars
| each { str to-int }
| rotate counter-clockwise _
| reject _
| rename bit1 bit2 bit3 bit4 bit5 bit6 bit7 bit8
| roll column 3

───┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────
 # │ bit4 │ bit5 │ bit6 │ bit7 │ bit8 │ bit1 │ bit2 │ bit3
───┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────
 0 │    0 │    0 │    1 │    0 │    0 │    0 │    0 │    0
───┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────
```

The tables was rolled correctly (32 in decimal, for above bitstring). However, the *last three header names* look confusing.
We can roll the cell contents only to fix it.

```
> echo '00000100'
| split chars
| each { str to-int }
| rotate counter-clockwise _
| reject _
| rename bit1 bit2 bit3 bit4 bit5 bit6 bit7 bit8
| roll column 3 --cells-only

───┬──────┬──────┬──────┬──────┬──────┬──────┬──────┬──────
 # │ bit1 │ bit2 │ bit3 │ bit4 │ bit5 │ bit6 │ bit7 │ bit8
───┼──────┼──────┼──────┼──────┼──────┼──────┼──────┼──────
 0 │    0 │    0 │    1 │    0 │    0 │    0 │    0 │    0
───┴──────┴──────┴──────┴──────┴──────┴──────┴──────┴──────
```

There we go. Let's compute it's decimal value now (should be 32)

```
> echo '00000100'
| split chars
| each { str to-int }
| rotate counter-clockwise _
| reject _
| roll column 3 --cells-only
| pivot bit --ignore-titles
| get bit
| reverse
| each --numbered { = $it.item * (2 ** $it.index) }
| math sum

32
```
2021-02-23 13:29:07 -05:00

64 lines
736 B
Rust

mod append;
mod autoenv;
mod autoenv_trust;
mod autoenv_untrust;
mod cal;
mod cd;
mod compact;
mod count;
mod cp;
mod def;
mod default;
mod drop;
mod each;
mod echo;
mod empty;
mod enter;
mod every;
mod first;
mod flatten;
mod format;
mod get;
mod group_by;
mod hash_;
mod headers;
mod histogram;
mod insert;
mod into_int;
mod keep;
mod last;
mod lines;
mod ls;
mod math;
mod merge;
mod mkdir;
mod move_;
mod open;
mod parse;
mod path;
mod prepend;
mod random;
mod range;
mod reduce;
mod rename;
mod reverse;
mod rm;
mod roll;
mod rotate;
mod save;
mod select;
mod semicolon;
mod skip;
mod sort_by;
mod split_by;
mod split_column;
mod split_row;
mod str_;
mod touch;
mod uniq;
mod update;
mod where_;
mod which;
mod with_env;
mod wrap;