forked from extern/nushell
9996e4a1f8
# Description Continuing from #12568, this PR further reduces the size of `Expr` from 64 to 40 bytes. It also reduces `Expression` from 128 to 96 bytes and `Type` from 32 to 24 bytes. This was accomplished by: - for `Expr` with multiple fields (e.g., `Expr::Thing(A, B, C)`), merging the fields into new AST struct types and then boxing this struct (e.g. `Expr::Thing(Box<ABC>)`). - replacing `Vec<T>` with `Box<[T]>` in multiple places. `Expr`s and `Expression`s should rarely be mutated, if at all, so this optimization makes sense. By reducing the size of these types, I didn't notice a large performance improvement (at least compared to #12568). But this PR does reduce the memory usage of nushell. My config is somewhat light so I only noticed a difference of 1.4MiB (38.9MiB vs 37.5MiB). --------- Co-authored-by: Stefan Holderbach <sholderbach@users.noreply.github.com>
97 lines
2.9 KiB
Rust
97 lines
2.9 KiB
Rust
use crate::math::{
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reducers::{reducer_for, Reduce},
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utils::run_with_function,
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};
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use nu_engine::command_prelude::*;
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const NS_PER_SEC: i64 = 1_000_000_000;
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#[derive(Clone)]
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pub struct SubCommand;
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impl Command for SubCommand {
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fn name(&self) -> &str {
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"math avg"
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}
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fn signature(&self) -> Signature {
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Signature::build("math avg")
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.input_output_types(vec![
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(Type::List(Box::new(Type::Duration)), Type::Duration),
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(Type::Duration, Type::Duration),
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(Type::List(Box::new(Type::Filesize)), Type::Filesize),
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(Type::Filesize, Type::Filesize),
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(Type::List(Box::new(Type::Number)), Type::Number),
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(Type::Number, Type::Number),
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(Type::Range, Type::Number),
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(Type::table(), Type::record()),
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(Type::record(), Type::record()),
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])
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.allow_variants_without_examples(true)
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.category(Category::Math)
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}
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fn usage(&self) -> &str {
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"Returns the average of a list of numbers."
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}
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fn search_terms(&self) -> Vec<&str> {
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vec!["average", "mean", "statistics"]
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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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run_with_function(call, input, average)
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}
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fn examples(&self) -> Vec<Example> {
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vec![
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Example {
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description: "Compute the average of a list of numbers",
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example: "[-50 100.0 25] | math avg",
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result: Some(Value::test_float(25.0)),
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},
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Example {
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description: "Compute the average of a list of durations",
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example: "[2sec 1min] | math avg",
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result: Some(Value::test_duration(31 * NS_PER_SEC)),
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},
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Example {
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description: "Compute the average of each column in a table",
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example: "[[a b]; [1 2] [3 4]] | math avg",
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result: Some(Value::test_record(record! {
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"a" => Value::test_int(2),
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"b" => Value::test_int(3),
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})),
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},
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]
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}
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}
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pub fn average(values: &[Value], span: Span, head: Span) -> Result<Value, ShellError> {
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let sum = reducer_for(Reduce::Summation);
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let total = &sum(Value::int(0, head), values.to_vec(), span, head)?;
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let span = total.span();
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match total {
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Value::Filesize { val, .. } => Ok(Value::filesize(val / values.len() as i64, span)),
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Value::Duration { val, .. } => Ok(Value::duration(val / values.len() as i64, span)),
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_ => total.div(head, &Value::int(values.len() as i64, head), head),
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}
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}
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#[cfg(test)]
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mod test {
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use super::*;
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#[test]
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fn test_examples() {
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use crate::test_examples;
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test_examples(SubCommand {})
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}
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}
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