nu_command/math/
max.rs

1use crate::math::{
2    reducers::{Reduce, reducer_for},
3    utils::run_with_function,
4};
5use nu_engine::command_prelude::*;
6
7#[derive(Clone)]
8pub struct MathMax;
9
10impl Command for MathMax {
11    fn name(&self) -> &str {
12        "math max"
13    }
14
15    fn signature(&self) -> Signature {
16        Signature::build("math max")
17            .input_output_types(vec![
18                (Type::List(Box::new(Type::Number)), Type::Number),
19                (Type::List(Box::new(Type::Duration)), Type::Duration),
20                (Type::List(Box::new(Type::Filesize)), Type::Filesize),
21                (Type::List(Box::new(Type::Any)), Type::Any),
22                (Type::Range, Type::Number),
23                (Type::table(), Type::record()),
24                (Type::record(), Type::record()),
25            ])
26            .allow_variants_without_examples(true)
27            .category(Category::Math)
28    }
29
30    fn description(&self) -> &str {
31        "Returns the maximum of a list of values, or of columns in a table."
32    }
33
34    fn search_terms(&self) -> Vec<&str> {
35        vec!["maximum", "largest"]
36    }
37
38    fn is_const(&self) -> bool {
39        true
40    }
41
42    fn run(
43        &self,
44        _engine_state: &EngineState,
45        _stack: &mut Stack,
46        call: &Call,
47        input: PipelineData,
48    ) -> Result<PipelineData, ShellError> {
49        run_with_function(call, input, maximum)
50    }
51
52    fn run_const(
53        &self,
54        _working_set: &StateWorkingSet,
55        call: &Call,
56        input: PipelineData,
57    ) -> Result<PipelineData, ShellError> {
58        run_with_function(call, input, maximum)
59    }
60
61    fn examples(&self) -> Vec<Example> {
62        vec![
63            Example {
64                description: "Find the maximum of a list of numbers",
65                example: "[-50 100 25] | math max",
66                result: Some(Value::test_int(100)),
67            },
68            Example {
69                description: "Find the maxima of the columns of a table",
70                example: "[{a: 1 b: 3} {a: 2 b: -1}] | math max",
71                result: Some(Value::test_record(record! {
72                    "a" => Value::test_int(2),
73                    "b" => Value::test_int(3),
74                })),
75            },
76            Example {
77                description: "Find the maximum of a list of dates",
78                example: "[2022-02-02 2022-12-30 2012-12-12] | math max",
79                result: Some(Value::test_date(
80                    "2022-12-30 00:00:00Z".parse().unwrap_or_default(),
81                )),
82            },
83        ]
84    }
85}
86
87pub fn maximum(values: &[Value], span: Span, head: Span) -> Result<Value, ShellError> {
88    let max_func = reducer_for(Reduce::Maximum);
89    max_func(Value::nothing(head), values.to_vec(), span, head)
90}
91
92#[cfg(test)]
93mod test {
94    use super::*;
95
96    #[test]
97    fn test_examples() {
98        use crate::test_examples;
99
100        test_examples(MathMax {})
101    }
102}
nu_command/math/max.rs

nu_command/math/
max.rs
