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c61075e20e
# Description
This PR allows byte streams to optionally be colored as being
specifically binary or string data, which guarantees that they'll be
converted to `Binary` or `String` appropriately on `into_value()`,
making them compatible with `Type` guarantees. This makes them
significantly more broadly usable for command input and output.
There is still an `Unknown` type for byte streams coming from external
commands, which uses the same behavior as we previously did where it's a
string if it's UTF-8.
A small number of commands were updated to take advantage of this, just
to prove the point. I will be adding more after this merges.
# User-Facing Changes
- New types in `describe`: `string (stream)`, `binary (stream)`
- These commands now return a stream if their input was a stream:
- `into binary`
- `into string`
- `bytes collect`
- `str join`
- `first` (binary)
- `last` (binary)
- `take` (binary)
- `skip` (binary)
- Streams that are explicitly binary colored will print as a streaming
hexdump
- example:
```nushell
1.. | each { into binary } | bytes collect
```
# Tests + Formatting
I've added some tests to cover it at a basic level, and it doesn't break
anything existing, but I do think more would be nice. Some of those will
come when I modify more commands to stream.
# After Submitting
There are a few things I'm not quite satisfied with:
- **String trimming behavior.** We automatically trim newlines from
streams from external commands, but I don't think we should do this with
internal commands. If I call a command that happens to turn my string
into a stream, I don't want the newline to suddenly disappear. I changed
this to specifically do it only on `Child` and `File`, but I don't know
if this is quite right, and maybe we should bring back the old flag for
`trim_end_newline`
- **Known binary always resulting in a hexdump.** It would be nice to
have a `print --raw`, so that we can put binary data on stdout
explicitly if we want to. This PR doesn't change how external commands
work though - they still dump straight to stdout.
Otherwise, here's the normal checklist:
- [ ] release notes
- [ ] docs update for plugin protocol changes (added `type` field)
---------
Co-authored-by: Ian Manske <ian.manske@pm.me>
68 lines
1.8 KiB
Rust
68 lines
1.8 KiB
Rust
use nu_plugin::{EngineInterface, EvaluatedCall, PluginCommand};
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use nu_protocol::{
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ByteStream, ByteStreamType, Category, Example, LabeledError, PipelineData, Signature, Type,
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Value,
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};
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use crate::ExamplePlugin;
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/// `<list<string>> | example collect-bytes`
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pub struct CollectBytes;
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impl PluginCommand for CollectBytes {
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type Plugin = ExamplePlugin;
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fn name(&self) -> &str {
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"example collect-bytes"
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}
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fn usage(&self) -> &str {
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"Example transformer to byte stream"
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}
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fn search_terms(&self) -> Vec<&str> {
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vec!["example"]
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}
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fn signature(&self) -> Signature {
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Signature::build(self.name())
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.input_output_types(vec![
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(Type::List(Type::String.into()), Type::String),
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(Type::List(Type::Binary.into()), Type::Binary),
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])
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.category(Category::Experimental)
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}
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fn examples(&self) -> Vec<Example> {
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vec![Example {
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example: "[a b] | example collect-bytes",
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description: "collect strings into one stream",
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result: Some(Value::test_string("ab")),
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}]
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}
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fn run(
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&self,
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_plugin: &ExamplePlugin,
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_engine: &EngineInterface,
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call: &EvaluatedCall,
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input: PipelineData,
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) -> Result<PipelineData, LabeledError> {
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Ok(PipelineData::ByteStream(
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ByteStream::from_result_iter(
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input.into_iter().map(Value::coerce_into_binary),
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call.head,
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None,
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ByteStreamType::Unknown,
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),
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None,
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))
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}
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}
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#[test]
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fn test_examples() -> Result<(), nu_protocol::ShellError> {
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use nu_plugin_test_support::PluginTest;
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PluginTest::new("example", ExamplePlugin.into())?.test_command_examples(&CollectBytes)
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}
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