cratification: part III of the math commands to nu-cmd-extra (#9674)

The following math commands are being moved to nu-cmd-extra

* e (euler)
* exp
* ln

This should conclude moving the extra math commands as discussed in
yesterday's
core team meeting...

The remaining math commands will stay in nu-command (for now)....

crates/nu-cmd-extra/src/example_test.rs

@@ -15,6 +15,7 @@ mod test_examples {
         check_example_input_and_output_types_match_command_signature,
     };
 
+    use crate::MathEuler;
     use crate::MathPi;
     use nu_protocol::{
         engine::{Command, EngineState, StateWorkingSet},
@@ -65,6 +66,7 @@ mod test_examples {
             working_set.add_decl(Box::new(nu_command::Enumerate));
             working_set.add_decl(Box::new(nu_cmd_lang::If));
             // math commands
+            working_set.add_decl(Box::new(MathEuler));
             working_set.add_decl(Box::new(MathPi));
             working_set.add_decl(Box::new(nu_command::MathRound));
 

crates/nu-cmd-extra/src/extra/math/euler.rs

@@ -0,0 +1,59 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Type, Value,
+};
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "math e"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("math e")
+            .input_output_types(vec![(Type::Any, Type::Float)])
+            .category(Category::Math)
+    }
+
+    fn usage(&self) -> &str {
+        "Returns the mathematical constant e (exp(1)/'1 | math exp')."
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["euler", "number", "constant"]
+    }
+
+    #[allow(clippy::approx_constant)]
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            example: "math e | math round --precision 3",
+            description: "Get the first three decimal digits of e",
+            result: Some(Value::test_float(2.718)),
+        }]
+    }
+
+    fn run(
+        &self,
+        _engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        _input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        Ok(Value::float(std::f64::consts::E, call.head).into_pipeline_data())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(SubCommand {})
+    }
+}

crates/nu-cmd-extra/src/extra/math/exp.rs

@@ -0,0 +1,98 @@
+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 exp"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("math exp")
+            .input_output_types(vec![(Type::Number, Type::Float)])
+            .vectorizes_over_list(true)
+            .category(Category::Math)
+    }
+
+    fn usage(&self) -> &str {
+        "Returns e raised to the power of x."
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["exponential", "exponentiation", "euler"]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let head = call.head;
+        // This doesn't match explicit nulls
+        if matches!(input, PipelineData::Empty) {
+            return Err(ShellError::PipelineEmpty { dst_span: head });
+        }
+        input.map(
+            move |value| operate(value, head),
+            engine_state.ctrlc.clone(),
+        )
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![
+            Example {
+                description: "Get e raised to the power of zero",
+                example: "0 | math exp",
+                result: Some(Value::test_float(1.0f64)),
+            },
+            Example {
+                description: "Get e (same as 'math e')",
+                example: "1 | math exp",
+                result: Some(Value::test_float(1.0f64.exp())),
+            },
+        ]
+    }
+}
+
+fn operate(value: Value, head: Span) -> 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!(),
+            };
+
+            Value::Float {
+                val: val.exp(),
+                span,
+            }
+        }
+        Value::Error { .. } => value,
+        other => Value::Error {
+            error: Box::new(ShellError::OnlySupportsThisInputType {
+                exp_input_type: "numeric".into(),
+                wrong_type: other.get_type().to_string(),
+                dst_span: head,
+                src_span: other.expect_span(),
+            }),
+        },
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(SubCommand {})
+    }
+}

crates/nu-cmd-extra/src/extra/math/ln.rs

@@ -0,0 +1,101 @@
+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 ln"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("math ln")
+            .input_output_types(vec![(Type::Number, Type::Float)])
+            .vectorizes_over_list(true)
+            .category(Category::Math)
+    }
+
+    fn usage(&self) -> &str {
+        "Returns the natural logarithm. Base: (math e)."
+    }
+
+    fn search_terms(&self) -> Vec<&str> {
+        vec!["natural", "logarithm", "inverse", "euler"]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let head = call.head;
+        // This doesn't match explicit nulls
+        if matches!(input, PipelineData::Empty) {
+            return Err(ShellError::PipelineEmpty { dst_span: head });
+        }
+        input.map(
+            move |value| operate(value, head),
+            engine_state.ctrlc.clone(),
+        )
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Get the natural logarithm of e",
+            example: "math e | math ln",
+            result: Some(Value::test_float(1.0f64)),
+        }]
+    }
+}
+
+fn operate(value: Value, head: Span) -> 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!(),
+            };
+
+            if val > 0.0 {
+                let val = val.ln();
+
+                Value::Float { val, span }
+            } else {
+                Value::Error {
+                    error: Box::new(ShellError::UnsupportedInput(
+                        "'ln' undefined for values outside the open interval (0, Inf).".into(),
+                        "value originates from here".into(),
+                        head,
+                        span,
+                    )),
+                }
+            }
+        }
+        Value::Error { .. } => value,
+        other => Value::Error {
+            error: Box::new(ShellError::OnlySupportsThisInputType {
+                exp_input_type: "numeric".into(),
+                wrong_type: other.get_type().to_string(),
+                dst_span: head,
+                src_span: other.expect_span(),
+            }),
+        },
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(SubCommand {})
+    }
+}

crates/nu-cmd-extra/src/extra/math/mod.rs

@@ -6,6 +6,9 @@ mod tan;
 mod tanh;
 
 mod egamma;
+mod euler;
+mod exp;
+mod ln;
 mod phi;
 mod pi;
 mod tau;
@@ -25,6 +28,9 @@ pub use tan::SubCommand as MathTan;
 pub use tanh::SubCommand as MathTanH;
 
 pub use egamma::SubCommand as MathEulerGamma;
+pub use euler::SubCommand as MathEuler;
+pub use exp::SubCommand as MathExp;
+pub use ln::SubCommand as MathLn;
 pub use phi::SubCommand as MathPhi;
 pub use pi::SubCommand as MathPi;
 pub use tau::SubCommand as MathTau;

crates/nu-cmd-extra/src/extra/mod.rs

@@ -38,7 +38,10 @@ pub use math::MathSinH;
 pub use math::MathTan;
 pub use math::MathTanH;
 
+pub use math::MathEuler;
 pub use math::MathEulerGamma;
+pub use math::MathExp;
+pub use math::MathLn;
 pub use math::MathPhi;
 pub use math::MathPi;
 pub use math::MathTau;
@@ -133,7 +136,10 @@ pub fn add_extra_command_context(mut engine_state: EngineState) -> EngineState {
             MathCosH,
             MathTanH,
             MathPi,
-            MathTau
+            MathTau,
+            MathEuler,
+            MathExp,
+            MathLn
         };
 
         working_set.render()