use nu_engine::CallExt;
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
Category, Example, IntoInterruptiblePipelineData, IntoPipelineData, PipelineData, ShellError,
Signature, SyntaxShape, Type, Value,
};
#[derive(Clone)]
pub struct Append;
impl Command for Append {
fn name(&self) -> &str {
"append"
}
fn signature(&self) -> nu_protocol::Signature {
Signature::build("append")
.input_output_types(vec![(Type::Any, Type::List(Box::new(Type::Any)))])
.required(
"row",
SyntaxShape::Any,
"The row, list, or table to append.",
)
.allow_variants_without_examples(true)
.category(Category::Filters)
}
fn usage(&self) -> &str {
"Append any number of rows to a table."
}
fn extra_usage(&self) -> &str {
r#"Be aware that this command 'unwraps' lists passed to it. So, if you pass a variable to it,
and you want the variable's contents to be appended without being unwrapped, it's wise to
pre-emptively wrap the variable in a list, like so: `append [$val]`. This way, `append` will
only unwrap the outer list, and leave the variable's contents untouched."#
}
fn search_terms(&self) -> Vec<&str> {
vec!["add", "concatenate"]
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
example: "[0 1 2 3] | append 4",
description: "Append one int to a list",
result: Some(Value::test_list(vec![
Value::test_int(0),
Value::test_int(1),
Value::test_int(2),
Value::test_int(3),
Value::test_int(4),
])),
},
Example {
example: "0 | append [1 2 3]",
description: "Append a list to an item",
result: Some(Value::test_list(vec![
Value::test_int(0),
Value::test_int(1),
Value::test_int(2),
Value::test_int(3),
])),
},
Example {
example: r#""a" | append ["b"] "#,
description: "Append a list of string to a string",
result: Some(Value::test_list(vec![
Value::test_string("a"),
Value::test_string("b"),
])),
},
Example {
example: "[0 1] | append [2 3 4]",
description: "Append three int items",
result: Some(Value::test_list(vec![
Value::test_int(0),
Value::test_int(1),
Value::test_int(2),
Value::test_int(3),
Value::test_int(4),
])),
},
Example {
example: "[0 1] | append [2 nu 4 shell]",
description: "Append ints and strings",
result: Some(Value::test_list(vec![
Value::test_int(0),
Value::test_int(1),
Value::test_int(2),
Value::test_string("nu"),
Value::test_int(4),
Value::test_string("shell"),
])),
},
Example {
example: "[0 1] | append 2..4",
description: "Append a range of ints to a list",
result: Some(Value::test_list(vec![
Value::test_int(0),
Value::test_int(1),
Value::test_int(2),
Value::test_int(3),
Value::test_int(4),
])),
},
]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let other: Value = call.req(engine_state, stack, 0)?;
let metadata = input.metadata();
Ok(input
.into_iter()
.chain(other.into_pipeline_data())
.into_pipeline_data_with_metadata(metadata, engine_state.ctrlc.clone()))
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_examples() {
use crate::test_examples;
test_examples(Append {})
}
}