93e8f6c05e
We split off the evaluation engine part of nu-cli into its own crate. This helps improve build times for nu-cli by 17% in my tests. It also helps us see a bit better what's the core engine portion vs the part specific to the interactive CLI piece. There's more than can be done here, but I think it's a good start in the right direction.
114 lines
3.5 KiB
Rust
114 lines
3.5 KiB
Rust
use crate::prelude::*;
|
|
use log::trace;
|
|
use nu_engine::evaluate_baseline_expr;
|
|
use nu_engine::WholeStreamCommand;
|
|
use nu_errors::ShellError;
|
|
use nu_protocol::{hir::ClassifiedCommand, Signature, SyntaxShape, UntaggedValue, Value};
|
|
|
|
pub struct SubCommand;
|
|
|
|
#[async_trait]
|
|
impl WholeStreamCommand for SubCommand {
|
|
fn name(&self) -> &str {
|
|
"keep while"
|
|
}
|
|
|
|
fn signature(&self) -> Signature {
|
|
Signature::build("keep while")
|
|
.required(
|
|
"condition",
|
|
SyntaxShape::RowCondition,
|
|
"The condition that must be met to keep rows",
|
|
)
|
|
.filter()
|
|
}
|
|
|
|
fn usage(&self) -> &str {
|
|
"Keeps rows while the condition matches."
|
|
}
|
|
|
|
async fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
|
|
let ctx = Arc::new(EvaluationContext::from_args(&args));
|
|
let call_info = args.evaluate_once().await?;
|
|
|
|
let block = call_info.args.expect_nth(0)?.clone();
|
|
|
|
let (condition, captured) = match block {
|
|
Value {
|
|
value: UntaggedValue::Block(captured_block),
|
|
tag,
|
|
} => {
|
|
if captured_block.block.block.len() != 1 {
|
|
return Err(ShellError::labeled_error(
|
|
"Expected a condition",
|
|
"expected a condition",
|
|
tag,
|
|
));
|
|
}
|
|
match captured_block.block.block[0].pipelines.get(0) {
|
|
Some(item) => match item.list.get(0) {
|
|
Some(ClassifiedCommand::Expr(expr)) => {
|
|
(Arc::new(expr.clone()), captured_block.captured.clone())
|
|
}
|
|
_ => {
|
|
return Err(ShellError::labeled_error(
|
|
"Expected a condition",
|
|
"expected a condition",
|
|
tag,
|
|
));
|
|
}
|
|
},
|
|
None => {
|
|
return Err(ShellError::labeled_error(
|
|
"Expected a condition",
|
|
"expected a condition",
|
|
tag,
|
|
));
|
|
}
|
|
}
|
|
}
|
|
Value { tag, .. } => {
|
|
return Err(ShellError::labeled_error(
|
|
"Expected a condition",
|
|
"expected a condition",
|
|
tag,
|
|
));
|
|
}
|
|
};
|
|
|
|
Ok(call_info
|
|
.input
|
|
.take_while(move |item| {
|
|
let condition = condition.clone();
|
|
let ctx = ctx.clone();
|
|
|
|
ctx.scope.enter_scope();
|
|
ctx.scope.add_var("$it", item.clone());
|
|
ctx.scope.add_vars(&captured.entries);
|
|
trace!("ITEM = {:?}", item);
|
|
|
|
async move {
|
|
let result = evaluate_baseline_expr(&*condition, &*ctx).await;
|
|
ctx.scope.exit_scope();
|
|
trace!("RESULT = {:?}", result);
|
|
|
|
matches!(result, Ok(ref v) if v.is_true())
|
|
}
|
|
})
|
|
.to_output_stream())
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::ShellError;
|
|
use super::SubCommand;
|
|
|
|
#[test]
|
|
fn examples_work_as_expected() -> Result<(), ShellError> {
|
|
use crate::examples::test as test_examples;
|
|
|
|
Ok(test_examples(SubCommand {})?)
|
|
}
|
|
}
|