nushell/crates/nu-cli/src/commands/debug.rs
Jason Gedge 522a828687
Move external closer to internal (#1611)
* 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>
2020-04-20 15:30:44 +12:00

50 lines
1.2 KiB
Rust

use crate::commands::WholeStreamCommand;
use crate::prelude::*;
use nu_errors::ShellError;
use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
pub struct Debug;
#[derive(Deserialize)]
pub struct DebugArgs {
raw: bool,
}
impl WholeStreamCommand for Debug {
fn name(&self) -> &str {
"debug"
}
fn signature(&self) -> Signature {
Signature::build("debug").switch("raw", "Prints the raw value representation.", Some('r'))
}
fn usage(&self) -> &str {
"Print the Rust debug representation of the values"
}
fn run(
&self,
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
args.process(registry, debug_value)?.run()
}
}
fn debug_value(
DebugArgs { raw }: DebugArgs,
RunnableContext { input, .. }: RunnableContext,
) -> Result<impl ToOutputStream, ShellError> {
Ok(input
.map(move |v| {
if raw {
ReturnSuccess::value(
UntaggedValue::string(format!("{:#?}", v)).into_untagged_value(),
)
} else {
ReturnSuccess::debug_value(v)
}
})
.to_output_stream())
}