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`
We introduce it here and allow it to work with regular lists (tables with no columns) as well as symmetric tables. Say we have two lists and wish to zip them, like so:
```
[0 2 4 6 8] | zip {
[1 3 5 7 9]
} | flatten
───┬───
0 │ 0
1 │ 1
2 │ 2
3 │ 3
4 │ 4
5 │ 5
6 │ 6
7 │ 7
8 │ 8
9 │ 9
───┴───
```
In the case for two tables instead:
```
[[symbol]; ['('] ['['] ['{']] | zip {
[[symbol]; [')'] [']'] ['}']]
} | each {
get symbol | $'($in.0)nushell($in.1)'
}
───┬───────────
0 │ (nushell)
1 │ [nushell]
2 │ {nushell}
───┴───────────
```
We very well support `nth 0 2 3 --skip 1 4` to select particular rows and skip some using a flag. However, in practice we deal with tables (whether they come from parsing or loading files and whatnot) where we don't know the size of the table up front (and everytime we have these, they may have different sizes). There are also other use cases when we use intermediate tables during processing and wish to always drop certain rows and **keep the rest**.
Usage:
```
... | drop nth 0
... | drop nth 3 8
```
* Refactor Hash code to simplify md5 and sha256 implementations
Md5 and Sha256 (and other future digests) require less boilerplate code
now. Error reporting includues the name of the hash again.
* Add missing hash sha256 test
Hashers now uses on Rust Crypto Digest trait which makes it trivial to
implement additional hash functions.
The original `md5` crate does not implement the Digest trait and was
replaced by `md-5` crate which does. Sha256 uses already included `sha2`
crate.
