Add basic trigonometric functions (#7258)

`math sin`
`math cos`
`math tan`

Support degrees with the flag `--degrees`/`-d`

crates/nu-command/src/default_context.rs

@@ -405,6 +405,9 @@ pub fn create_default_context() -> EngineState {
             MathStddev,
             MathSum,
             MathVariance,
+            MathSin,
+            MathCos,
+            MathTan,
             MathPi,
             MathEuler,
         };

crates/nu-command/src/math/cos.rs

@@ -0,0 +1,107 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, Span, Type, Value};
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "math cos"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("math cos")
+            .switch("degrees", "Use degrees instead of radians", Some('d'))
+            .input_output_types(vec![(Type::Number, Type::Float)])
+            .vectorizes_over_list(true)
+            .category(Category::Math)
+    }
+
+    fn usage(&self) -> &str {
+        "Returns the cosine of the number."
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["trigonometry"]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        let head = call.head;
+        let use_degrees = call.has_flag("degrees");
+        input.map(
+            move |value| operate(value, head, use_degrees),
+            engine_state.ctrlc.clone(),
+        )
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Apply the cosine to pi",
+                example: "math pi | math cos",
+                result: Some(Value::test_float(-1f64)),
+            },
+            Example {
+                description: "Apply the cosine to a list of angles in degrees",
+                example: "[0 90 180 270 360] | math cos -d",
+                result: Some(Value::List {
+                    vals: vec![
+                        Value::test_float(1f64),
+                        Value::test_float(0f64),
+                        Value::test_float(-1f64),
+                        Value::test_float(0f64),
+                        Value::test_float(1f64),
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+        ]
+    }
+}
+
+fn operate(value: Value, head: Span, use_degrees: bool) -> Value {
+    match value {
+        numeric @ (Value::Int { .. } | Value::Float { .. }) => {
+            let (val, span) = match numeric {
+                Value::Int { val, span } => (val as f64, span),
+                Value::Float { val, span } => (val, span),
+                _ => unreachable!(),
+            };
+
+            let val = if use_degrees { val.to_radians() } else { val };
+
+            Value::Float {
+                val: val.cos(),
+                span,
+            }
+        }
+        other => Value::Error {
+            error: ShellError::UnsupportedInput(
+                format!(
+                    "Only numerical values are supported, input type: {:?}",
+                    other.get_type()
+                ),
+                other.span().unwrap_or(head),
+            ),
+        },
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(SubCommand {})
+    }
+}

crates/nu-command/src/math/mod.rs

@@ -1,6 +1,7 @@
 mod abs;
 mod avg;
 mod ceil;
+mod cos;
 mod euler;
 mod eval;
 mod floor;
@@ -13,9 +14,11 @@ mod pi;
 mod product;
 mod reducers;
 mod round;
+mod sin;
 mod sqrt;
 mod stddev;
 mod sum;
+mod tan;
 mod utils;
 mod variance;
 
@@ -36,5 +39,9 @@ pub use stddev::SubCommand as MathStddev;
 pub use sum::SubCommand as MathSum;
 pub use variance::SubCommand as MathVariance;
 
+pub use cos::SubCommand as MathCos;
+pub use sin::SubCommand as MathSin;
+pub use tan::SubCommand as MathTan;
+
 pub use euler::SubCommand as MathEuler;
 pub use pi::SubCommand as MathPi;

crates/nu-command/src/math/sin.rs

@@ -0,0 +1,107 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, Span, Type, Value};
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "math sin"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("math sin")
+            .switch("degrees", "Use degrees instead of radians", Some('d'))
+            .input_output_types(vec![(Type::Number, Type::Float)])
+            .vectorizes_over_list(true)
+            .category(Category::Math)
+    }
+
+    fn usage(&self) -> &str {
+        "Returns the sine of the number."
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["trigonometry"]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        let head = call.head;
+        let use_degrees = call.has_flag("degrees");
+        input.map(
+            move |value| operate(value, head, use_degrees),
+            engine_state.ctrlc.clone(),
+        )
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Apply the sine to π/2",
+                example: "(math pi) / 2 | math sin",
+                result: Some(Value::test_float(1f64)),
+            },
+            Example {
+                description: "Apply the sine to a list of angles in degrees",
+                example: "[0 90 180 270 360] | math sin -d | math round --precision 4",
+                result: Some(Value::List {
+                    vals: vec![
+                        Value::test_float(0f64),
+                        Value::test_float(1f64),
+                        Value::test_float(0f64),
+                        Value::test_float(-1f64),
+                        Value::test_float(0f64),
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+        ]
+    }
+}
+
+fn operate(value: Value, head: Span, use_degrees: bool) -> Value {
+    match value {
+        numeric @ (Value::Int { .. } | Value::Float { .. }) => {
+            let (val, span) = match numeric {
+                Value::Int { val, span } => (val as f64, span),
+                Value::Float { val, span } => (val, span),
+                _ => unreachable!(),
+            };
+
+            let val = if use_degrees { val.to_radians() } else { val };
+
+            Value::Float {
+                val: val.sin(),
+                span,
+            }
+        }
+        other => Value::Error {
+            error: ShellError::UnsupportedInput(
+                format!(
+                    "Only numerical values are supported, input type: {:?}",
+                    other.get_type()
+                ),
+                other.span().unwrap_or(head),
+            ),
+        },
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(SubCommand {})
+    }
+}

crates/nu-command/src/math/tan.rs

@@ -0,0 +1,105 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{Category, Example, PipelineData, ShellError, Signature, Span, Type, Value};
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "math tan"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("math tan")
+            .switch("degrees", "Use degrees instead of radians", Some('d'))
+            .input_output_types(vec![(Type::Number, Type::Float)])
+            .vectorizes_over_list(true)
+            .category(Category::Math)
+    }
+
+    fn usage(&self) -> &str {
+        "Returns the tangent of the number."
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["trigonometry"]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        let head = call.head;
+        let use_degrees = call.has_flag("degrees");
+        input.map(
+            move |value| operate(value, head, use_degrees),
+            engine_state.ctrlc.clone(),
+        )
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Apply the tangent to pi/4",
+                example: "(math pi) / 4 | math tan",
+                result: Some(Value::test_float(1f64)),
+            },
+            Example {
+                description: "Apply the tangent to a list of angles in degrees",
+                example: "[-45 0 45] | math tan -d",
+                result: Some(Value::List {
+                    vals: vec![
+                        Value::test_float(-1f64),
+                        Value::test_float(0f64),
+                        Value::test_float(1f64),
+                    ],
+                    span: Span::test_data(),
+                }),
+            },
+        ]
+    }
+}
+
+fn operate(value: Value, head: Span, use_degrees: bool) -> Value {
+    match value {
+        numeric @ (Value::Int { .. } | Value::Float { .. }) => {
+            let (val, span) = match numeric {
+                Value::Int { val, span } => (val as f64, span),
+                Value::Float { val, span } => (val, span),
+                _ => unreachable!(),
+            };
+
+            let val = if use_degrees { val.to_radians() } else { val };
+
+            Value::Float {
+                val: val.tan(),
+                span,
+            }
+        }
+        other => Value::Error {
+            error: ShellError::UnsupportedInput(
+                format!(
+                    "Only numerical values are supported, input type: {:?}",
+                    other.get_type()
+                ),
+                other.span().unwrap_or(head),
+            ),
+        },
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(SubCommand {})
+    }
+}