nu_cmd_extra/extra/math/
cos.rs

1use nu_engine::command_prelude::*;
2
3#[derive(Clone)]
4pub struct MathCos;
5
6impl Command for MathCos {
7    fn name(&self) -> &str {
8        "math cos"
9    }
10
11    fn signature(&self) -> Signature {
12        Signature::build("math cos")
13            .switch("degrees", "Use degrees instead of radians", Some('d'))
14            .input_output_types(vec![
15                (Type::Number, Type::Float),
16                (
17                    Type::List(Box::new(Type::Number)),
18                    Type::List(Box::new(Type::Float)),
19                ),
20            ])
21            .category(Category::Math)
22    }
23
24    fn description(&self) -> &str {
25        "Returns the cosine of the number."
26    }
27
28    fn search_terms(&self) -> Vec<&str> {
29        vec!["trigonometry"]
30    }
31
32    fn run(
33        &self,
34        engine_state: &EngineState,
35        stack: &mut Stack,
36        call: &Call,
37        input: PipelineData,
38    ) -> Result<PipelineData, ShellError> {
39        let head = call.head;
40        let use_degrees = call.has_flag(engine_state, stack, "degrees")?;
41        // This doesn't match explicit nulls
42        if let PipelineData::Empty = input {
43            return Err(ShellError::PipelineEmpty { dst_span: head });
44        }
45        input.map(
46            move |value| operate(value, head, use_degrees),
47            engine_state.signals(),
48        )
49    }
50
51    fn examples(&self) -> Vec<Example<'_>> {
52        vec![
53            Example {
54                description: "Apply the cosine to π",
55                example: "3.141592 | math cos | math round --precision 4",
56                result: Some(Value::test_float(-1f64)),
57            },
58            Example {
59                description: "Apply the cosine to a list of angles in degrees",
60                example: "[0 90 180 270 360] | math cos --degrees",
61                result: Some(Value::list(
62                    vec![
63                        Value::test_float(1f64),
64                        Value::test_float(0f64),
65                        Value::test_float(-1f64),
66                        Value::test_float(0f64),
67                        Value::test_float(1f64),
68                    ],
69                    Span::test_data(),
70                )),
71            },
72        ]
73    }
74}
75
76fn operate(value: Value, head: Span, use_degrees: bool) -> Value {
77    match value {
78        numeric @ (Value::Int { .. } | Value::Float { .. }) => {
79            let span = numeric.span();
80            let (val, span) = match numeric {
81                Value::Int { val, .. } => (val as f64, span),
82                Value::Float { val, .. } => (val, span),
83                _ => unreachable!(),
84            };
85
86            let val = if use_degrees { val.to_radians() } else { val };
87
88            Value::float(val.cos(), span)
89        }
90        Value::Error { .. } => value,
91        other => Value::error(
92            ShellError::OnlySupportsThisInputType {
93                exp_input_type: "numeric".into(),
94                wrong_type: other.get_type().to_string(),
95                dst_span: head,
96                src_span: other.span(),
97            },
98            head,
99        ),
100    }
101}
102
103#[cfg(test)]
104mod test {
105    use super::*;
106
107    #[test]
108    fn test_examples() {
109        use crate::test_examples;
110
111        test_examples(MathCos {})
112    }
113}
nu_cmd_extra/extra/math/cos.rs

nu_cmd_extra/extra/math/
cos.rs
