forked from extern/nushell
84 lines
2.0 KiB
Rust
84 lines
2.0 KiB
Rust
use crate::command_registry::CommandRegistry;
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use crate::commands::WholeStreamCommand;
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use crate::deserializer::NumericRange;
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use crate::prelude::*;
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use nu_errors::ShellError;
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use nu_protocol::{RangeInclusion, ReturnSuccess, Signature, SyntaxShape};
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use nu_source::Tagged;
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#[derive(Deserialize)]
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struct RangeArgs {
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area: Tagged<NumericRange>,
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}
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pub struct Range;
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#[async_trait]
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impl WholeStreamCommand for Range {
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fn name(&self) -> &str {
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"range"
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}
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fn signature(&self) -> Signature {
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Signature::build("range").required(
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"rows ",
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SyntaxShape::Range,
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"range of rows to return: Eg) 4..7 (=> from 4 to 7)",
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)
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}
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fn usage(&self) -> &str {
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"Return only the selected rows"
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}
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async fn run(
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&self,
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args: CommandArgs,
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registry: &CommandRegistry,
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) -> Result<OutputStream, ShellError> {
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range(args, registry).await
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}
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}
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async fn range(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
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let registry = registry.clone();
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let (RangeArgs { area }, input) = args.process(®istry).await?;
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let range = area.item;
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let (from, left_inclusive) = range.from;
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let (to, right_inclusive) = range.to;
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let from = from.map(|from| *from as usize).unwrap_or(0).saturating_add(
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if left_inclusive == RangeInclusion::Inclusive {
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0
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} else {
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1
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},
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);
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let to = to
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.map(|to| *to as usize)
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.unwrap_or(usize::MAX)
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.saturating_sub(if right_inclusive == RangeInclusion::Inclusive {
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0
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} else {
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1
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});
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Ok(input
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.skip(from)
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.take(to - from + 1)
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.map(ReturnSuccess::value)
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.to_output_stream())
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}
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#[cfg(test)]
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mod tests {
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use super::Range;
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use super::ShellError;
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#[test]
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fn examples_work_as_expected() -> Result<(), ShellError> {
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use crate::examples::test as test_examples;
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Ok(test_examples(Range {})?)
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}
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}
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