nushell/crates/nu-cli/src/commands/which_.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

111 lines
2.9 KiB
Rust

use crate::commands::WholeStreamCommand;
use crate::prelude::*;
use indexmap::map::IndexMap;
use nu_errors::ShellError;
use nu_protocol::{Primitive, ReturnSuccess, Signature, SyntaxShape, UntaggedValue, Value};
use nu_source::Tagged;
pub struct Which;
impl WholeStreamCommand for Which {
fn name(&self) -> &str {
"which"
}
fn signature(&self) -> Signature {
Signature::build("which")
.required("application", SyntaxShape::String, "application")
.switch("all", "list all executables", Some('a'))
}
fn usage(&self) -> &str {
"Finds a program file."
}
fn run(
&self,
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
args.process(registry, which)?.run()
}
}
/// Shortcuts for creating an entry to the output table
fn entry(arg: impl Into<String>, path: Value, builtin: bool, tag: Tag) -> Value {
let mut map = IndexMap::new();
map.insert(
"arg".to_string(),
UntaggedValue::Primitive(Primitive::String(arg.into())).into_value(tag.clone()),
);
map.insert("path".to_string(), path);
map.insert(
"builtin".to_string(),
UntaggedValue::Primitive(Primitive::Boolean(builtin)).into_value(tag.clone()),
);
UntaggedValue::row(map).into_value(tag)
}
macro_rules! entry_builtin {
($arg:expr, $tag:expr) => {
entry(
$arg.clone(),
UntaggedValue::Primitive(Primitive::String("nushell built-in command".to_string()))
.into_value($tag.clone()),
true,
$tag,
)
};
}
macro_rules! entry_path {
($arg:expr, $path:expr, $tag:expr) => {
entry(
$arg.clone(),
UntaggedValue::Primitive(Primitive::Path($path)).into_value($tag.clone()),
false,
$tag,
)
};
}
#[derive(Deserialize, Debug)]
struct WhichArgs {
application: Tagged<String>,
all: bool,
}
fn which(
WhichArgs { application, all }: WhichArgs,
RunnableContext { registry, .. }: RunnableContext,
) -> Result<OutputStream, ShellError> {
let external = application.starts_with('^');
let item = if external {
application.item[1..].to_string()
} else {
application.item.clone()
};
let stream = async_stream! {
if !external {
let builtin = registry.has(&item);
if builtin {
yield ReturnSuccess::value(entry_builtin!(item, application.tag.clone()));
}
}
if let Ok(paths) = ichwh::which_all(&item).await {
for path in paths {
yield ReturnSuccess::value(entry_path!(item, path.into(), application.tag.clone()));
}
}
};
if all {
Ok(stream.to_output_stream())
} else {
Ok(stream.take(1).to_output_stream())
}
}