nushell/src/commands/echo.rs
Jonathan Turner 193b00764b
Stream support (#812)
* Moves off of draining between filters. Instead, the sink will pull on the stream, and will drain element-wise. This moves the whole stream to being lazy.
* Adds ctrl-c support and connects it into some of the key points where we pull on the stream. If a ctrl-c is detect, we immediately halt pulling on the stream and return to the prompt.
* Moves away from having a SourceMap where anchor locations are stored. Now AnchorLocation is kept directly in the Tag.
* To make this possible, split tag and span. Span is largely used in the parser and is copyable. Tag is now no longer copyable.
2019-10-13 17:12:43 +13:00

72 lines
1.7 KiB
Rust

use crate::data::Value;
use crate::errors::ShellError;
use crate::prelude::*;
use crate::parser::registry::Signature;
pub struct Echo;
impl PerItemCommand for Echo {
fn name(&self) -> &str {
"echo"
}
fn signature(&self) -> Signature {
Signature::build("echo").rest(SyntaxShape::Any)
}
fn usage(&self) -> &str {
"Echo the arguments back to the user."
}
fn run(
&self,
call_info: &CallInfo,
registry: &CommandRegistry,
raw_args: &RawCommandArgs,
_input: Tagged<Value>,
) -> Result<OutputStream, ShellError> {
run(call_info, registry, raw_args)
}
}
fn run(
call_info: &CallInfo,
_registry: &CommandRegistry,
_raw_args: &RawCommandArgs,
) -> Result<OutputStream, ShellError> {
let name = call_info.name_tag.clone();
let mut output = String::new();
let mut first = true;
if let Some(ref positional) = call_info.args.positional {
for i in positional {
match i.as_string() {
Ok(s) => {
if !first {
output.push_str(" ");
} else {
first = false;
}
output.push_str(&s);
}
_ => {
return Err(ShellError::type_error(
"a string-compatible value",
i.tagged_type_name(),
))
}
}
}
}
let stream = VecDeque::from(vec![Ok(ReturnSuccess::Value(
Value::string(output).tagged(name),
))]);
Ok(stream.to_output_stream())
}