Merge pull request #282 from luccasmmg/engine-q-math

math: floor, ceil, median and mode

crates/nu-command/src/default_context.rs

@@ -64,8 +64,12 @@ pub fn create_default_context() -> EngineState {
             Math,
             MathAbs,
             MathAvg,
+            MathCeil,
+            MathFloor,
             MathMax,
+            MathMedian,
             MathMin,
+            MathMode,
             MathProduct,
             MathRound,
             MathSqrt,

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

@@ -0,0 +1,73 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, Value};
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "math ceil"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("math ceil")
+    }
+
+    fn usage(&self) -> &str {
+        "Applies the ceil function to a list of numbers"
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        let head = call.head;
+        input.map(
+            move |value| operate(value, head),
+            engine_state.ctrlc.clone(),
+        )
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Apply the ceil function to a list of numbers",
+            example: "[1.5 2.3 -3.1] | math ceil",
+            result: Some(Value::List {
+                vals: vec![Value::test_int(2), Value::test_int(3), Value::test_int(-3)],
+                span: Span::unknown(),
+            }),
+        }]
+    }
+}
+
+fn operate(value: Value, head: Span) -> Value {
+    match value {
+        Value::Int { .. } => value,
+        Value::Float { val, span } => Value::Float {
+            val: val.ceil(),
+            span,
+        },
+        other => Value::Error {
+            error: ShellError::UnsupportedInput(
+                String::from("Only numerical values are supported"),
+                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/floor.rs

@@ -0,0 +1,73 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, Value};
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "math floor"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("math floor")
+    }
+
+    fn usage(&self) -> &str {
+        "Applies the floor function to a list of numbers"
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        let head = call.head;
+        input.map(
+            move |value| operate(value, head),
+            engine_state.ctrlc.clone(),
+        )
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Apply the floor function to a list of numbers",
+            example: "[1.5 2.3 -3.1] | math floor",
+            result: Some(Value::List {
+                vals: vec![Value::test_int(1), Value::test_int(2), Value::test_int(-4)],
+                span: Span::unknown(),
+            }),
+        }]
+    }
+}
+
+fn operate(value: Value, head: Span) -> Value {
+    match value {
+        Value::Int { .. } => value,
+        Value::Float { val, span } => Value::Float {
+            val: val.floor(),
+            span,
+        },
+        other => Value::Error {
+            error: ShellError::UnsupportedInput(
+                String::from("Only numerical values are supported"),
+                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/median.rs

@@ -0,0 +1,121 @@
+use crate::math::avg::average;
+use crate::math::utils::run_with_function;
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, Value};
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "math median"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("math median")
+    }
+
+    fn usage(&self) -> &str {
+        "Gets the median of a list of numbers"
+    }
+
+    fn run(
+        &self,
+        _engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        run_with_function(call, input, median)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Get the median of a list of numbers",
+            example: "[3 8 9 12 12 15] | math median",
+            result: Some(Value::Float {
+                val: 10.5,
+                span: Span::unknown(),
+            }),
+        }]
+    }
+}
+
+enum Pick {
+    MedianAverage,
+    Median,
+}
+
+pub fn median(values: &[Value], head: &Span) -> Result<Value, ShellError> {
+    let take = if values.len() % 2 == 0 {
+        Pick::MedianAverage
+    } else {
+        Pick::Median
+    };
+
+    let mut sorted = vec![];
+
+    for item in values {
+        sorted.push(item.clone());
+    }
+
+    if let Some(Err(values)) = values
+        .windows(2)
+        .map(|elem| {
+            if elem[0].partial_cmp(&elem[1]).is_none() {
+                return Err(ShellError::OperatorMismatch {
+                    op_span: *head,
+                    lhs_ty: elem[0].get_type(),
+                    lhs_span: elem[0].span()?,
+                    rhs_ty: elem[1].get_type(),
+                    rhs_span: elem[1].span()?,
+                });
+            }
+            Ok(elem[0].partial_cmp(&elem[1]).unwrap())
+        })
+        .find(|elem| elem.is_err())
+    {
+        return Err(values);
+    }
+
+    sorted.sort_by(|a, b| a.partial_cmp(b).unwrap());
+
+    match take {
+        Pick::Median => {
+            let idx = (values.len() as f64 / 2.0).floor() as usize;
+            let out = sorted
+                .get(idx)
+                .ok_or_else(|| ShellError::UnsupportedInput("Empty input".to_string(), *head))?;
+            Ok(out.clone())
+        }
+        Pick::MedianAverage => {
+            let idx_end = (values.len() / 2) as usize;
+            let idx_start = idx_end - 1;
+
+            let left = sorted
+                .get(idx_start)
+                .ok_or_else(|| ShellError::UnsupportedInput("Empty input".to_string(), *head))?
+                .clone();
+
+            let right = sorted
+                .get(idx_end)
+                .ok_or_else(|| ShellError::UnsupportedInput("Empty input".to_string(), *head))?
+                .clone();
+
+            average(&[left, right], 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

@@ -1,8 +1,12 @@
 mod abs;
 mod avg;
+mod ceil;
 pub mod command;
+mod floor;
 mod max;
+mod median;
 mod min;
+mod mode;
 mod product;
 mod reducers;
 mod round;
@@ -12,9 +16,13 @@ mod utils;
 
 pub use abs::SubCommand as MathAbs;
 pub use avg::SubCommand as MathAvg;
+pub use ceil::SubCommand as MathCeil;
 pub use command::MathCommand as Math;
+pub use floor::SubCommand as MathFloor;
 pub use max::SubCommand as MathMax;
+pub use median::SubCommand as MathMedian;
 pub use min::SubCommand as MathMin;
+pub use mode::SubCommand as MathMode;
 pub use product::SubCommand as MathProduct;
 pub use round::SubCommand as MathRound;
 pub use sqrt::SubCommand as MathSqrt;

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

@@ -0,0 +1,174 @@
+use crate::math::utils::run_with_function;
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{Example, PipelineData, ShellError, Signature, Span, Value};
+use std::cmp::Ordering;
+
+#[derive(Clone)]
+pub struct SubCommand;
+
+#[derive(Hash, Eq, PartialEq, Debug)]
+enum NumberTypes {
+    Float,
+    Int,
+    Duration,
+    Filesize,
+}
+
+#[derive(Hash, Eq, PartialEq, Debug)]
+struct HashableType {
+    bytes: [u8; 8],
+    original_type: NumberTypes,
+}
+
+impl HashableType {
+    fn new(bytes: [u8; 8], original_type: NumberTypes) -> HashableType {
+        HashableType {
+            bytes,
+            original_type,
+        }
+    }
+}
+
+impl Command for SubCommand {
+    fn name(&self) -> &str {
+        "math mode"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("math mode")
+    }
+
+    fn usage(&self) -> &str {
+        "Gets the most frequent element(s) from a list of numbers or tables"
+    }
+
+    fn run(
+        &self,
+        _engine_state: &EngineState,
+        _stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        run_with_function(call, input, mode)
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Get the mode(s) of a list of numbers",
+            example: "[3 3 9 12 12 15] | math mode",
+            result: Some(Value::List {
+                vals: vec![Value::test_int(3), Value::test_int(12)],
+                span: Span::unknown(),
+            }),
+        }]
+    }
+}
+
+pub fn mode(values: &[Value], head: &Span) -> Result<Value, ShellError> {
+    if let Some(Err(values)) = values
+        .windows(2)
+        .map(|elem| {
+            if elem[0].partial_cmp(&elem[1]).is_none() {
+                return Err(ShellError::OperatorMismatch {
+                    op_span: *head,
+                    lhs_ty: elem[0].get_type(),
+                    lhs_span: elem[0].span()?,
+                    rhs_ty: elem[1].get_type(),
+                    rhs_span: elem[1].span()?,
+                });
+            }
+            Ok(elem[0].partial_cmp(&elem[1]).unwrap())
+        })
+        .find(|elem| elem.is_err())
+    {
+        return Err(values);
+    }
+    //In e-q, Value doesn't implement Hash or Eq, so we have to get the values inside
+    // But f64 doesn't implement Hash, so we get the binary representation to use as
+    // key in the HashMap
+    let hashable_values: Result<Vec<HashableType>, ShellError> = values
+        .iter()
+        .map(|val| match val {
+            Value::Int { val, .. } => Ok(HashableType::new(val.to_ne_bytes(), NumberTypes::Int)),
+            Value::Duration { val, .. } => {
+                Ok(HashableType::new(val.to_ne_bytes(), NumberTypes::Duration))
+            }
+            Value::Float { val, .. } => {
+                Ok(HashableType::new(val.to_ne_bytes(), NumberTypes::Float))
+            }
+            Value::Filesize { val, .. } => {
+                Ok(HashableType::new(val.to_ne_bytes(), NumberTypes::Filesize))
+            }
+            other => Err(ShellError::UnsupportedInput(
+                "Unable to give a result with this input".to_string(),
+                other.span().unwrap(),
+            )),
+        })
+        .collect::<Result<Vec<HashableType>, ShellError>>();
+    if let Err(not_hashable) = hashable_values {
+        return Err(not_hashable);
+    }
+
+    let mut frequency_map = std::collections::HashMap::new();
+    for v in hashable_values.unwrap() {
+        let counter = frequency_map.entry(v).or_insert(0);
+        *counter += 1;
+    }
+
+    let mut max_freq = -1;
+    let mut modes = Vec::<Value>::new();
+    for (value, frequency) in &frequency_map {
+        match max_freq.cmp(frequency) {
+            Ordering::Less => {
+                max_freq = *frequency;
+                modes.clear();
+                modes.push(recreate_value(value, *head));
+            }
+            Ordering::Equal => {
+                modes.push(recreate_value(value, *head));
+            }
+            Ordering::Greater => (),
+        }
+    }
+
+    modes.sort_by(|a, b| a.partial_cmp(b).unwrap());
+    Ok(Value::List {
+        vals: modes,
+        span: *head,
+    })
+}
+
+fn recreate_value(hashable_value: &HashableType, head: Span) -> Value {
+    let bytes = hashable_value.bytes;
+    match &hashable_value.original_type {
+        NumberTypes::Int => Value::Int {
+            val: i64::from_ne_bytes(bytes),
+            span: head,
+        },
+        NumberTypes::Float => Value::Float {
+            val: f64::from_ne_bytes(bytes),
+            span: head,
+        },
+        NumberTypes::Duration => Value::Duration {
+            val: i64::from_ne_bytes(bytes),
+            span: head,
+        },
+        NumberTypes::Filesize => Value::Filesize {
+            val: i64::from_ne_bytes(bytes),
+            span: head,
+        },
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(SubCommand {})
+    }
+}