Add support for skip and where

src/commands/skip.rs

@@ -0,0 +1,29 @@
+use crate::errors::ShellError;
+use crate::prelude::*;
+use derive_new::new;
+
+#[derive(new)]
+pub struct Skip;
+
+// TODO: "Amount remaining" wrapper
+
+impl crate::Command for Skip {
+    fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+        let amount = args.args[0].as_int()?;
+
+        let amount = if args.input.len() > amount as usize {
+            amount as usize
+        } else {
+            args.input.len()
+        };
+
+        let out: VecDeque<ReturnValue> = args
+            .input
+            .into_iter()
+            .skip(amount)
+            .map(|v| ReturnValue::Value(v))
+            .collect();
+
+        Ok(out)
+    }
+}

src/commands/where_.rs

@@ -0,0 +1,30 @@
+use crate::errors::ShellError;
+use crate::object::base::find;
+use crate::prelude::*;
+use derive_new::new;
+
+#[derive(new)]
+pub struct Where;
+
+impl crate::Command for Where {
+    fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+        if args.args.is_empty() {
+            return Err(ShellError::string("select requires a field"));
+        }
+
+        let field: Result<String, _> = args.args[0].as_string();
+        let field = field?;
+
+        let op: Result<String, _> = args.args[1].as_string();
+        let op = op?;
+
+        let objects = args
+            .input
+            .iter()
+            .filter(|item| find(&item, &field, &op, &args.args[2]))
+            .map(|item| ReturnValue::Value(item.copy()))
+            .collect();
+
+        Ok(objects)
+    }
+}