Port over the reverse command from nushell (#303)

* initial commit of reverse
* reverse is working, now move on to the examples
* add in working examples for reverse
* #[allow(clippy::needless_collect)]

crates/nu-command/src/default_context.rs

@@ -86,6 +86,7 @@ pub fn create_default_context() -> EngineState {
             ParEach,
             Ps,
             Range,
+            Reverse,
             Rm,
             Select,
             Shuffle,

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

@@ -6,6 +6,7 @@ mod length;
 mod lines;
 mod par_each;
 mod range;
+mod reverse;
 mod select;
 mod shuffle;
 mod where_;
@@ -20,6 +21,7 @@ pub use length::Length;
 pub use lines::Lines;
 pub use par_each::ParEach;
 pub use range::Range;
+pub use reverse::Reverse;
 pub use select::Select;
 pub use shuffle::Shuffle;
 pub use where_::Where;

crates/nu-command/src/filters/reverse.rs

@@ -0,0 +1,63 @@
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{
+    Example, IntoInterruptiblePipelineData, PipelineData, ShellError, Signature, Span, Value,
+};
+
+#[derive(Clone)]
+pub struct Reverse;
+
+impl Command for Reverse {
+    fn name(&self) -> &str {
+        "reverse"
+    }
+
+    fn signature(&self) -> nu_protocol::Signature {
+        Signature::build("reverse")
+    }
+
+    fn usage(&self) -> &str {
+        "Reverses the table."
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            example: "[0,1,2,3] | reverse",
+            description: "Reverse the items",
+            result: Some(Value::List {
+                vals: vec![
+                    Value::test_int(3),
+                    Value::test_int(2),
+                    Value::test_int(1),
+                    Value::test_int(0),
+                ],
+                span: Span::unknown(),
+            }),
+        }]
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        _stack: &mut Stack,
+        _call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        #[allow(clippy::needless_collect)]
+        let v: Vec<_> = input.into_iter().collect();
+        let iter = v.into_iter().rev();
+        Ok(iter.into_pipeline_data(engine_state.ctrlc.clone()))
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_examples() {
+        use crate::test_examples;
+
+        test_examples(Reverse {})
+    }
+}