nushell/src/commands/compact.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

62 lines
1.5 KiB
Rust

use crate::commands::WholeStreamCommand;
use crate::data::base::UntaggedValue;
use crate::errors::ShellError;
use crate::parser::registry::{CommandRegistry, Signature};
use crate::prelude::*;
use futures::stream::StreamExt;
use nu_source::Tagged;
pub struct Compact;
#[derive(Deserialize)]
pub struct CompactArgs {
rest: Vec<Tagged<String>>,
}
impl WholeStreamCommand for Compact {
fn name(&self) -> &str {
"compact"
}
fn signature(&self) -> Signature {
Signature::build("compact").rest(SyntaxShape::Any, "the columns to compact from the table")
}
fn usage(&self) -> &str {
"Creates a table with non-empty rows"
}
fn run(
&self,
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
args.process(registry, compact)?.run()
}
}
pub fn compact(
CompactArgs { rest: columns }: CompactArgs,
RunnableContext { input, .. }: RunnableContext,
) -> Result<OutputStream, ShellError> {
let objects = input.values.filter(move |item| {
let keep = if columns.is_empty() {
item.is_some()
} else {
match item {
Value {
value: UntaggedValue::Row(ref r),
..
} => columns
.iter()
.all(|field| r.get_data(field).borrow().is_some()),
_ => false,
}
};
futures::future::ready(keep)
});
Ok(objects.from_input_stream())
}