nushell/crates/nu-command/src/debug/view_span.rs
Jérémy Audiger a5c604c283
Uniformize usage() and extra_usage() message ending for commands helper. (#8268)
# Description

Working on uniformizing the ending messages regarding methods usage()
and extra_usage(). This is related to the issue
https://github.com/nushell/nushell/issues/5066 after discussing it with
@jntrnr

# 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.
2023-02-28 21:33:02 -08:00

69 lines
2.4 KiB
Rust

use nu_engine::CallExt;
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, Spanned,
SyntaxShape, Type, Value,
};
#[derive(Clone)]
pub struct ViewSpan;
impl Command for ViewSpan {
fn name(&self) -> &str {
"view span"
}
fn usage(&self) -> &str {
"View the contents of a span."
}
fn extra_usage(&self) -> &str {
"This command is meant for debugging purposes.\nIt allows you to view the contents of nushell spans.\nOne way to get spans is to pipe something into 'debug --raw'.\nThen you can use the Span { start, end } values as the start and end values for this command."
}
fn signature(&self) -> nu_protocol::Signature {
Signature::build("view span")
.input_output_types(vec![(Type::Nothing, Type::String)])
.required("start", SyntaxShape::Int, "start of the span")
.required("end", SyntaxShape::Int, "end of the span")
.category(Category::Debug)
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
_input: PipelineData,
) -> Result<PipelineData, ShellError> {
let start_span: Spanned<usize> = call.req(engine_state, stack, 0)?;
let end_span: Spanned<usize> = call.req(engine_state, stack, 1)?;
if start_span.item < end_span.item {
let bin_contents =
engine_state.get_span_contents(&Span::new(start_span.item, end_span.item));
Ok(
Value::string(String::from_utf8_lossy(bin_contents), call.head)
.into_pipeline_data(),
)
} else {
Err(ShellError::GenericError(
"Cannot view span".to_string(),
"this start and end does not correspond to a viewable value".to_string(),
Some(call.head),
None,
Vec::new(),
))
}
}
fn examples(&self) -> Vec<Example> {
vec![Example {
description: "View the source of a span. 1 and 2 are just example values. Use the return of debug -r to get the actual values",
example: r#"some | pipeline | or | variable | debug -r; view span 1 2"#,
result: None,
}]
}
}