1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132

use crate::prelude::*;
use nu_engine::WholeStreamCommand;
use nu_errors::ShellError;
use nu_protocol::{Signature, UntaggedValue};

pub struct Uniq;

#[async_trait]
impl WholeStreamCommand for Uniq {
    fn name(&self) -> &str {
        "uniq"
    }

    fn signature(&self) -> Signature {
        Signature::build("uniq").switch("count", "Count the unique rows", Some('c'))
    }

    fn usage(&self) -> &str {
        "Return the unique rows."
    }

    async fn run(&self, args: CommandArgs) -> Result<OutputStream, ShellError> {
        uniq(args).await
    }

    fn examples(&self) -> Vec<Example> {
        vec![
            Example {
                description: "Remove duplicate rows of a list/table",
                example: "echo [2 3 3 4] | uniq",
                result: Some(vec![
                    UntaggedValue::int(2).into(),
                    UntaggedValue::int(3).into(),
                    UntaggedValue::int(4).into(),
                ]),
            },
            Example {
                description: "Remove duplicate rows and show counts of a list/table",
                example: "echo [1 2 2] | uniq -c",
                result: Some(vec![
                    UntaggedValue::row(indexmap! {
                    "value".to_string() => UntaggedValue::int(1).into(),
                    "count".to_string() => UntaggedValue::int(1).into(),
                    })
                    .into(),
                    UntaggedValue::row(indexmap! {
                    "value".to_string() => UntaggedValue::int(2).into(),
                    "count".to_string() => UntaggedValue::int(2).into(),
                    })
                    .into(),
                ]),
            },
        ]
    }
}

async fn uniq(args: CommandArgs) -> Result<OutputStream, ShellError> {
    let args = args.evaluate_once().await?;
    let should_show_count = args.has("count");
    let input = args.input;
    let uniq_values = {
        let mut counter = IndexMap::<nu_protocol::Value, usize>::new();
        for line in input.into_vec().await {
            *counter.entry(line).or_insert(0) += 1;
        }
        counter
    };

    let mut values_vec_deque = VecDeque::new();

    if should_show_count {
        for item in uniq_values {
            use nu_protocol::Value;
            let value = {
                match item.0.value {
                    UntaggedValue::Row(mut row) => {
                        row.entries.insert(
                            "count".to_string(),
                            UntaggedValue::int(item.1).into_untagged_value(),
                        );
                        Value {
                            value: UntaggedValue::Row(row),
                            tag: item.0.tag,
                        }
                    }
                    UntaggedValue::Primitive(p) => {
                        let mut map = IndexMap::<String, Value>::new();
                        map.insert(
                            "value".to_string(),
                            UntaggedValue::Primitive(p).into_untagged_value(),
                        );
                        map.insert(
                            "count".to_string(),
                            UntaggedValue::int(item.1).into_untagged_value(),
                        );
                        Value {
                            value: UntaggedValue::row(map),
                            tag: item.0.tag,
                        }
                    }
                    UntaggedValue::Table(_) => {
                        return Err(ShellError::labeled_error(
                            "uniq -c cannot operate on tables.",
                            "source",
                            item.0.tag.span,
                        ))
                    }
                    UntaggedValue::Error(_) | UntaggedValue::Block(_) => item.0,
                }
            };
            values_vec_deque.push_back(value);
        }
    } else {
        for item in uniq_values {
            values_vec_deque.push_back(item.0);
        }
    }

    Ok(futures::stream::iter(values_vec_deque).to_output_stream())
}

#[cfg(test)]
mod tests {
    use super::ShellError;
    use super::Uniq;
    #[test]
    fn examples_work_as_expected() -> Result<(), ShellError> {
        use crate::examples::test as test_examples;

        test_examples(Uniq {})
    }
}