nushell/src/commands/split_column.rs
2019-10-28 18:15:35 +13:00

108 lines
3.7 KiB
Rust

use crate::commands::WholeStreamCommand;
use crate::data::{Primitive, TaggedDictBuilder, Value};
use crate::errors::ShellError;
use crate::prelude::*;
use log::trace;
#[derive(Deserialize)]
struct SplitColumnArgs {
separator: Tagged<String>,
rest: Vec<Tagged<String>>,
#[serde(rename(deserialize = "collapse-empty"))]
collapse_empty: bool,
}
pub struct SplitColumn;
impl WholeStreamCommand for SplitColumn {
fn name(&self) -> &str {
"split-column"
}
fn signature(&self) -> Signature {
Signature::build("split-column")
.required(
"separator",
SyntaxShape::Any,
"the character that denotes what separates columns",
)
.switch("collapse-empty", "remove empty columns")
.rest(SyntaxShape::Member, "column names to give the new columns")
}
fn usage(&self) -> &str {
"Split row contents across multiple columns via the separator."
}
fn run(
&self,
args: CommandArgs,
registry: &CommandRegistry,
) -> Result<OutputStream, ShellError> {
args.process(registry, split_column)?.run()
}
}
fn split_column(
SplitColumnArgs {
separator,
rest,
collapse_empty,
}: SplitColumnArgs,
RunnableContext { input, name, .. }: RunnableContext,
) -> Result<OutputStream, ShellError> {
Ok(input
.values
.map(move |v| match v.item {
Value::Primitive(Primitive::String(ref s)) => {
let splitter = separator.replace("\\n", "\n");
trace!("splitting with {:?}", splitter);
let split_result: Vec<_> = if collapse_empty {
s.split(&splitter).filter(|s| !s.is_empty()).collect()
} else {
s.split(&splitter).collect()
};
trace!("split result = {:?}", split_result);
let positional: Vec<_> = rest.iter().map(|f| f.item.clone()).collect();
// If they didn't provide column names, make up our own
if positional.len() == 0 {
let mut gen_columns = vec![];
for i in 0..split_result.len() {
gen_columns.push(format!("Column{}", i + 1));
}
let mut dict = TaggedDictBuilder::new(v.tag());
for (&k, v) in split_result.iter().zip(gen_columns.iter()) {
dict.insert(v.clone(), Primitive::String(k.into()));
}
ReturnSuccess::value(dict.into_tagged_value())
} else if split_result.len() == positional.len() {
let mut dict = TaggedDictBuilder::new(v.tag());
for (&k, v) in split_result.iter().zip(positional.iter()) {
dict.insert(v, Value::Primitive(Primitive::String(k.into())));
}
ReturnSuccess::value(dict.into_tagged_value())
} else {
let mut dict = TaggedDictBuilder::new(v.tag());
for (&k, v) in split_result.iter().zip(positional.iter()) {
dict.insert(v, Value::Primitive(Primitive::String(k.into())));
}
ReturnSuccess::value(dict.into_tagged_value())
}
}
_ => Err(ShellError::labeled_error_with_secondary(
"Expected a string from pipeline",
"requires string input",
&name,
"value originates from here",
v.tag(),
)),
})
.to_output_stream())
}