use indexmap::IndexMap;
use nu_errors::ShellError;
use nu_protocol::{TaggedDictBuilder, UntaggedValue, Value};
use nu_source::Tag;
use nu_value_ext::as_string;
#[allow(clippy::type_complexity)]
pub fn group(
values: &Value,
grouper: &Option<Box<dyn Fn(usize, &Value) -> Result<String, ShellError> + Send>>,
tag: impl Into<Tag>,
) -> Result<Value, ShellError> {
let tag = tag.into();
let mut groups: IndexMap<String, Vec<Value>> = IndexMap::new();
for (idx, value) in values.table_entries().enumerate() {
let group_key = if let Some(ref grouper) = grouper {
grouper(idx, value)
} else {
as_string(value)
};
let group = groups.entry(group_key?).or_insert(vec![]);
group.push((*value).clone());
}
let mut out = TaggedDictBuilder::new(&tag);
for (k, v) in &groups {
out.insert_untagged(k, UntaggedValue::table(v));
}
Ok(out.into_value())
}