forked from extern/nushell
122 lines
3.2 KiB
Rust
122 lines
3.2 KiB
Rust
use nu_engine::CallExt;
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use nu_protocol::{
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ast::Call,
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engine::{Command, EngineState, Stack},
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Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
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};
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use super::super::values::NuDataFrame;
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#[derive(Clone)]
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pub struct ToNu;
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impl Command for ToNu {
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fn name(&self) -> &str {
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"into nu"
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}
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fn usage(&self) -> &str {
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"Converts a section of the dataframe into nushell Table"
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}
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fn signature(&self) -> Signature {
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Signature::build(self.name())
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.named(
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"rows",
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SyntaxShape::Number,
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"number of rows to be shown",
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Some('n'),
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)
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.switch("tail", "shows tail rows", Some('t'))
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.input_type(Type::Custom("dataframe".into()))
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.output_type(Type::Any)
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.category(Category::Custom("dataframe".into()))
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}
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fn examples(&self) -> Vec<Example> {
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let cols = vec!["a".into(), "b".into()];
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let rec_1 = Value::Record {
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cols: cols.clone(),
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vals: vec![Value::test_int(1), Value::test_int(2)],
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span: Span::test_data(),
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};
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let rec_2 = Value::Record {
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cols,
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vals: vec![Value::test_int(3), Value::test_int(4)],
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span: Span::test_data(),
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};
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vec![
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Example {
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description: "Shows head rows from dataframe",
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example: "[[a b]; [1 2] [3 4]] | into df | into nu",
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result: Some(Value::List {
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vals: vec![rec_1, rec_2.clone()],
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span: Span::test_data(),
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}),
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},
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Example {
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description: "Shows tail rows from dataframe",
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example: "[[a b]; [1 2] [5 6] [3 4]] | into df | into nu -t -n 1",
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result: Some(Value::List {
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vals: vec![rec_2],
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span: Span::test_data(),
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}),
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},
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]
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}
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fn run(
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&self,
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engine_state: &EngineState,
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stack: &mut Stack,
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call: &Call,
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input: PipelineData,
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) -> Result<PipelineData, ShellError> {
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command(engine_state, stack, call, input)
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}
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}
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fn command(
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engine_state: &EngineState,
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stack: &mut Stack,
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call: &Call,
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input: PipelineData,
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) -> Result<PipelineData, ShellError> {
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let rows: Option<usize> = call.get_flag(engine_state, stack, "rows")?;
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let tail: bool = call.has_flag("tail");
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let df = NuDataFrame::try_from_pipeline(input, call.head)?;
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let values = if tail {
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df.tail(rows, call.head)?
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} else {
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// if rows is specified, return those rows, otherwise return everything
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if rows.is_some() {
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df.head(rows, call.head)?
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} else {
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df.head(Some(df.height()), call.head)?
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}
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};
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println!("len: {}", values.len());
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let value = Value::List {
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vals: values,
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span: call.head,
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};
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Ok(PipelineData::Value(value, None))
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}
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#[cfg(test)]
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mod test {
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use super::super::super::test_dataframe::test_dataframe;
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use super::*;
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#[test]
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fn test_examples() {
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test_dataframe(vec![Box::new(ToNu {})])
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}
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}
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