nushell/src/commands/lines.rs
Yehuda Katz e4226def16 Extract core stuff into own crates
This commit extracts five new crates:

- nu-source, which contains the core source-code handling logic in Nu,
  including Text, Span, and also the pretty.rs-based debug logic
- nu-parser, which is the parser and expander logic
- nu-protocol, which is the bulk of the types and basic conveniences
  used by plugins
- nu-errors, which contains ShellError, ParseError and error handling
  conveniences
- nu-textview, which is the textview plugin extracted into a crate

One of the major consequences of this refactor is that it's no longer
possible to `impl X for Spanned<Y>` outside of the `nu-source` crate, so
a lot of types became more concrete (Value became a concrete type
instead of Spanned<Value>, for example).

This also turned a number of inherent methods in the main nu crate into
plain functions (impl Value {} became a bunch of functions in the
`value` namespace in `crate::data::value`).
2019-12-02 10:54:12 -08:00

72 lines
2 KiB
Rust

use crate::commands::WholeStreamCommand;
use crate::prelude::*;
use log::trace;
use nu_errors::ShellError;
use nu_protocol::{Primitive, ReturnSuccess, Signature, UntaggedValue};
pub struct Lines;
impl WholeStreamCommand for Lines {
fn name(&self) -> &str {
"lines"
}
fn signature(&self) -> Signature {
Signature::build("lines")
}
fn usage(&self) -> &str {
"Split single string into rows, one per line."
}
fn run(
&self,
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
lines(args, registry)
}
}
// TODO: "Amount remaining" wrapper
fn lines(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
let args = args.evaluate_once(registry)?;
let tag = args.name_tag();
let name_span = tag.span;
let input = args.input;
let stream = input
.values
.map(move |v| match v.value {
UntaggedValue::Primitive(Primitive::String(s)) => {
let split_result: Vec<_> = s.lines().filter(|s| s.trim() != "").collect();
trace!("split result = {:?}", split_result);
let mut result = VecDeque::new();
for s in split_result {
result.push_back(ReturnSuccess::value(
UntaggedValue::Primitive(Primitive::String(s.into())).into_untagged_value(),
));
}
result
}
_ => {
let mut result = VecDeque::new();
let value_span = v.tag.span;
result.push_back(Err(ShellError::labeled_error_with_secondary(
"Expected a string from pipeline",
"requires string input",
name_span,
"value originates from here",
value_span,
)));
result
}
})
.flatten();
Ok(stream.to_output_stream())
}