nushell/src/commands/append.rs
Yehuda Katz f70c6d5d48 Extract nu_source into a crate
This commit extracts Tag, Span, Text, as well as source-related debug
facilities into a new crate called nu_source.

This change is much bigger than one might have expected because the
previous code relied heavily on implementing inherent methods on
`Tagged<T>` and `Spanned<T>`, which is no longer possible.

As a result, this change creates more concrete types instead of using
`Tagged<T>`. One notable example: Tagged<Value> became Value, and Value
became UntaggedValue.

This change clarifies the intent of the code in many places, but it does
make it a big change.
2019-11-25 07:37:33 -08:00

48 lines
1.0 KiB
Rust

use crate::commands::WholeStreamCommand;
use crate::errors::ShellError;
use crate::parser::CommandRegistry;
use crate::prelude::*;
#[derive(Deserialize)]
struct AppendArgs {
row: Value,
}
pub struct Append;
impl WholeStreamCommand for Append {
fn name(&self) -> &str {
"append"
}
fn signature(&self) -> Signature {
Signature::build("append").required(
"row value",
SyntaxShape::Any,
"the value of the row to append to the table",
)
}
fn usage(&self) -> &str {
"Append the given row to the table"
}
fn run(
&self,
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
args.process(registry, append)?.run()
}
}
fn append(
AppendArgs { row }: AppendArgs,
RunnableContext { input, .. }: RunnableContext,
) -> Result<OutputStream, ShellError> {
let mut after: VecDeque<Value> = VecDeque::new();
after.push_back(row);
Ok(OutputStream::from_input(input.values.chain(after)))
}