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eaec480f42
# Description This fix changes pipelines to allow them to actually be empty. Mapping over empty pipelines gives empty pipelines. Empty pipelines immediately return `None` when iterated. This removes a some of where `Span::new(0, 0)` was coming from, though there are other cases where we still use it. # User-Facing Changes None # Tests + Formatting Don't forget to add tests that cover your changes. Make sure you've run and fixed any issues with these commands: - `cargo fmt --all -- --check` to check standard code formatting (`cargo fmt --all` applies these changes) - `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A clippy::needless_collect` to check that you're using the standard code style - `cargo test --workspace` to check that all tests pass # After Submitting If your PR had any user-facing changes, update [the documentation](https://github.com/nushell/nushell.github.io) after the PR is merged, if necessary. This will help us keep the docs up to date.
67 lines
2.0 KiB
Rust
67 lines
2.0 KiB
Rust
use nu_protocol::ast::Call;
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use nu_protocol::engine::{Command, EngineState, Stack};
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use nu_protocol::{Category, Example, PipelineData, Signature, Span, SyntaxShape, Type, Value};
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#[derive(Clone)]
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pub struct Alias;
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impl Command for Alias {
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fn name(&self) -> &str {
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"alias"
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}
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fn usage(&self) -> &str {
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"Alias a command (with optional flags) to a new name"
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}
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fn signature(&self) -> nu_protocol::Signature {
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Signature::build("alias")
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.input_output_types(vec![(Type::Nothing, Type::Nothing)])
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.required("name", SyntaxShape::String, "name of the alias")
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.required(
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"initial_value",
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SyntaxShape::Keyword(b"=".to_vec(), Box::new(SyntaxShape::Expression)),
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"equals sign followed by value",
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)
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.category(Category::Core)
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}
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fn extra_usage(&self) -> &str {
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r#"This command is a parser keyword. For details, check:
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https://www.nushell.sh/book/thinking_in_nu.html"#
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}
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fn is_parser_keyword(&self) -> bool {
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true
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}
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fn search_terms(&self) -> Vec<&str> {
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vec!["abbr", "aka", "fn", "func", "function"]
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}
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fn run(
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&self,
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_engine_state: &EngineState,
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_stack: &mut Stack,
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_call: &Call,
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_input: PipelineData,
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) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
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Ok(PipelineData::empty())
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}
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fn examples(&self) -> Vec<Example> {
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vec![
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Example {
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description: "Alias ll to ls -l",
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example: "alias ll = ls -l",
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result: Some(Value::nothing(Span::test_data())),
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},
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Example {
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description: "Make an alias that makes a list of all custom commands",
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example: "alias customs = ($nu.scope.commands | where is_custom | get command)",
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result: Some(Value::nothing(Span::test_data())),
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},
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]
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}
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}
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