Very often we need to work with tables (say extracted from unstructured data or some
kind of final report, timeseries, and the like).
It's inevitable we will be having columns that we can't know beforehand what their names
will be, or how many.
Also, we may end up with certain cells having values we may want to remove as we explore.
Here, `update cells` fundamentally goes over every cell in the table coming in and updates
the cell's contents with the output of the block passed. Basic example here:
```
> [
[ ty1, t2, ty];
[ 1, a, $nothing]
[(wrap), (0..<10), 1Mb]
[ 1s, ({}), 1000000]
[ $true, $false, ([[]])]
] | update cells { describe }
───┬───────────────────────┬───────────────────────────┬──────────
# │ ty1 │ t2 │ ty
───┼───────────────────────┼───────────────────────────┼──────────
0 │ integer │ string │ nothing
1 │ row Column(table of ) │ range[[integer, integer)] │ filesize
2 │ string │ nothing │ integer
3 │ boolean │ boolean │ table of
───┴───────────────────────┴───────────────────────────┴──────────
```
and another one (in the examples) for cases, say we have a timeseries table generated and
we want to remove the zeros and have empty strings and save it out to something like CSV.
```
> [
[2021-04-16, 2021-06-10, 2021-09-18, 2021-10-15, 2021-11-16, 2021-11-17, 2021-11-18];
[ 37, 0, 0, 0, 37, 0, 0]
] | update cells {|value| i
if ($value | into int) == 0 {
""
} {
$value
}
}
───┬────────────┬────────────┬────────────┬────────────┬────────────┬────────────┬────────────
# │ 2021-04-16 │ 2021-06-10 │ 2021-09-18 │ 2021-10-15 │ 2021-11-16 │ 2021-11-17 │ 2021-11-18
───┼────────────┼────────────┼────────────┼────────────┼────────────┼────────────┼────────────
0 │ 37 │ │ │ │ 37 │ │
───┴────────────┴────────────┴────────────┴────────────┴────────────┴────────────┴────────────
```
```
> [
[ msg, labels, span];
["The message", "Helpful message here", ([[start, end]; [0, 141]])]
] | error make
error: The message
┌─ shell:1:1
│
1 │ ╭ [
2 │ │ [ msg, labels, span];
3 │ │ ["The message", "Helpful message here", ([[start, end]; [0, 141]])]
│ ╰─────────────────────────────────────────────────────────────────────^ Helpful message here
```
Adding a more flexible approach for creating error values. One use case, for instance is the
idea of a test framework. A failed assertion instead of printing to the screen it could create
tables with more details of the failed assertion and pass it to this command for making a full
fledge error that Nu can show. This can (and should) be extended for capturing error values as well
in the pipeline. One could also use it for inspection.
For example: `.... | error inspect { # inspection here }`
or "error handling" as well, like so: `.... | error capture { fix here }`
However, we start here only with `error make` that creates an error value for you with limited support for the time being.
* Add subcommand `into filesize`
It's currently not possible to convert a number or a string containing a number
into a filesize. The only way to create an instance of filesize type today is
with a literal in nushell syntax. This commit adds the `into filesize`
subcommand so that file sizes can be created from the outputs of programs
producing numbers or strings, like standard unix tools.
There is a limitation with this - it doesn't currently parse values like `10 MB`
or `10 MiB`, it can only look at the number itself. If the desire is there, more
flexible parsing can be added.
* fixup! Add subcommand `into filesize`
* fixup! Add subcommand `into filesize`
