forked from extern/nushell
522a828687
* Refactor InputStream and affected commands. First, making `values` private and leaning on the `Stream` implementation makes consumes of `InputStream` less likely to have to change in the future, if we change what an `InputStream` is internally. Second, we're dropping `Option<InputStream>` as the input to pipelines, internals, and externals. Instead, `InputStream.is_empty` can be used to check for "emptiness". Empty streams are typically only ever used as the first input to a pipeline. * Add run_external internal command. We want to push external commands closer to internal commands, eventually eliminating the concept of "external" completely. This means we can consolidate a couple of things: - Variable evaluation (for example, `$it`, `$nu`, alias vars) - Behaviour of whole stream vs per-item external execution It should also make it easier for us to start introducing argument signatures for external commands, * Update run_external.rs * Update run_external.rs * Update run_external.rs * Update run_external.rs Co-authored-by: Jonathan Turner <jonathandturner@users.noreply.github.com>
44 lines
985 B
Rust
44 lines
985 B
Rust
use crate::commands::WholeStreamCommand;
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use crate::context::CommandRegistry;
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use crate::prelude::*;
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use nu_errors::ShellError;
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use nu_protocol::Signature;
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pub struct Reverse;
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impl WholeStreamCommand for Reverse {
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fn name(&self) -> &str {
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"reverse"
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}
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fn signature(&self) -> Signature {
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Signature::build("reverse")
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}
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fn usage(&self) -> &str {
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"Reverses the table."
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}
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fn run(
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&self,
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args: CommandArgs,
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registry: &CommandRegistry,
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) -> Result<OutputStream, ShellError> {
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reverse(args, registry)
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}
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}
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fn reverse(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
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let args = args.evaluate_once(registry)?;
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let (input, _args) = args.parts();
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let input = input.collect::<Vec<_>>();
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let output = input.map(move |mut vec| {
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vec.reverse();
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futures::stream::iter(vec)
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});
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Ok(output.flatten_stream().from_input_stream())
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}
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