Restructure and make commands uniform

Cargo.toml

@@ -9,15 +9,15 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-rustyline = "4.0.0"
-sysinfo = "0.8.3"
+rustyline = "4.1.0"
+sysinfo = "0.8.4"
 chrono = "0.4.6"
 chrono-tz = "0.5.1"
 derive-new = "0.5.6"
 prettytable-rs = "0.8.0"
 itertools = "0.8.0"
 ansi_term = "0.11.0"
-conch-parser = "0.1.0"
+conch-parser = "0.1.1"
 nom = "5.0.0-beta1"
 subprocess = "0.1.18"
 dunce = "1.0.0"
@@ -28,3 +28,4 @@ chrono-humanize = "0.0.11"
 byte-unit = "2.1.0"
 ordered-float = "1.0.2"
 prettyprint = "0.6.0"
+cursive = { version = "0.12.0", features = ["pancurses-backend"], default-features = false }

src/commands.rs

@@ -1,5 +1,6 @@
 crate mod args;
 crate mod cd;
+crate mod classified;
 crate mod command;
 crate mod ls;
 crate mod ps;
@@ -12,4 +13,4 @@ crate mod to_array;
 crate mod view;
 crate mod where_;
 
-crate use to_array::to_array;
+crate use to_array::stream_to_array;

src/commands/cd.rs

@@ -1,25 +1,19 @@
 use crate::errors::ShellError;
 use crate::prelude::*;
-use derive_new::new;
 use std::env;
 
-#[derive(new)]
-pub struct Cd;
+pub fn cd(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    let target = match args.args.first() {
+        // TODO: This needs better infra
+        None => return Err(ShellError::string(format!("cd must take one arg"))),
+        Some(v) => v.as_string()?.clone(),
+    };
 
-impl crate::Command for Cd {
-    fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
-        let target = match args.args.first() {
-            // TODO: This needs better infra
-            None => return Err(ShellError::string(format!("cd must take one arg"))),
-            Some(v) => v.as_string()?.clone(),
-        };
+    let cwd = args.env.cwd().to_path_buf();
 
-        let cwd = args.env.cwd().to_path_buf();
-
-        let mut stream = VecDeque::new();
-        let path = dunce::canonicalize(cwd.join(&target).as_path())?;
-        let _ = env::set_current_dir(&path);
-        stream.push_back(ReturnValue::change_cwd(path));
-        Ok(stream)
-    }
+    let mut stream = VecDeque::new();
+    let path = dunce::canonicalize(cwd.join(&target).as_path())?;
+    let _ = env::set_current_dir(&path);
+    stream.push_back(ReturnValue::change_cwd(path));
+    Ok(stream)
 }

src/commands/classified.rs

@@ -0,0 +1,55 @@
+use crate::prelude::*;
+use std::sync::Arc;
+use subprocess::Exec;
+
+crate enum ClassifiedCommand {
+    Internal(InternalCommand),
+    External(ExternalCommand),
+}
+
+impl ClassifiedCommand {
+    crate fn run(
+        self,
+        input: VecDeque<Value>,
+        context: &mut crate::Context,
+    ) -> Result<VecDeque<Value>, ShellError> {
+        match self {
+            ClassifiedCommand::Internal(internal) => {
+                let result = context.run_command(internal.command, internal.args, input)?;
+
+                let mut next = VecDeque::new();
+
+                for v in result {
+                    match v {
+                        ReturnValue::Action(action) => match action {
+                            crate::CommandAction::ChangeCwd(cwd) => context.env.cwd = cwd,
+                        },
+
+                        ReturnValue::Value(v) => next.push_back(v),
+                    }
+                }
+
+                Ok(next)
+            }
+
+            ClassifiedCommand::External(external) => {
+                Exec::shell(&external.name)
+                    .args(&external.args)
+                    .cwd(context.env.cwd())
+                    .join()
+                    .unwrap();
+                Ok(VecDeque::new())
+            }
+        }
+    }
+}
+
+crate struct InternalCommand {
+    crate command: Arc<dyn Command>,
+    crate args: Vec<Value>,
+}
+
+crate struct ExternalCommand {
+    crate name: String,
+    crate args: Vec<String>,
+}

src/commands/command.rs

@@ -1,22 +1,29 @@
 use crate::errors::ShellError;
 use crate::object::Value;
 use crate::prelude::*;
+use crate::Context;
 use std::path::PathBuf;
 
 pub struct CommandArgs<'caller> {
-    pub host: &'caller dyn Host,
+    pub host: &'caller mut dyn Host,
     pub env: &'caller crate::Environment,
     pub args: Vec<Value>,
     pub input: VecDeque<Value>,
 }
 
-pub trait CommandBlueprint {
-    fn create(
-        &self,
-        input: Vec<Value>,
-        host: &dyn crate::Host,
-        env: &mut crate::Environment,
-    ) -> Result<Box<dyn Command>, ShellError>;
+impl CommandArgs<'caller> {
+    crate fn from_context(
+        ctx: &'caller mut Context,
+        args: Vec<Value>,
+        input: VecDeque<Value>,
+    ) -> CommandArgs<'caller> {
+        CommandArgs {
+            host: &mut ctx.host,
+            env: &ctx.env,
+            args,
+            input,
+        }
+    }
 }
 
 #[derive(Debug)]
@@ -45,3 +52,12 @@ impl ReturnValue {
 pub trait Command {
     fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError>;
 }
+
+impl<F> Command for F
+where
+    F: Fn(CommandArgs<'_>) -> Result<VecDeque<ReturnValue>, ShellError>,
+{
+    fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+        self(args)
+    }
+}

src/commands/ls.rs

@@ -1,25 +1,18 @@
 use crate::errors::ShellError;
 use crate::object::{dir_entry_dict, Value};
 use crate::prelude::*;
-use derive_new::new;
 
-#[derive(new)]
-pub struct Ls;
+pub fn ls(args: CommandArgs<'value>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    let cwd = args.env.cwd().to_path_buf();
 
-impl crate::Command for Ls {
-    fn run(&self, args: CommandArgs<'value>) -> Result<VecDeque<ReturnValue>, ShellError> {
-        let cwd = args.env.cwd().to_path_buf();
+    let entries = std::fs::read_dir(&cwd).map_err(|e| ShellError::string(format!("{:?}", e)))?;
 
-        let entries =
-            std::fs::read_dir(&cwd).map_err(|e| ShellError::string(format!("{:?}", e)))?;
+    let mut shell_entries = VecDeque::new();
 
-        let mut shell_entries = VecDeque::new();
-
-        for entry in entries {
-            let value = Value::Object(dir_entry_dict(&entry?)?);
-            shell_entries.push_back(ReturnValue::Value(value))
-        }
-
-        Ok(shell_entries)
+    for entry in entries {
+        let value = Value::Object(dir_entry_dict(&entry?)?);
+        shell_entries.push_back(ReturnValue::Value(value))
     }
+
+    Ok(shell_entries)
 }

src/commands/ps.rs

@@ -2,24 +2,18 @@ use crate::errors::ShellError;
 use crate::object::process::process_dict;
 use crate::object::Value;
 use crate::prelude::*;
-use derive_new::new;
 use sysinfo::SystemExt;
 
-#[derive(new)]
-pub struct Ps;
+pub fn ps(_args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    let mut system = sysinfo::System::new();
+    system.refresh_all();
 
-impl crate::Command for Ps {
-    fn run(&self, _args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
-        let mut system = sysinfo::System::new();
-        system.refresh_all();
+    let list = system.get_process_list();
 
-        let list = system.get_process_list();
+    let list = list
+        .into_iter()
+        .map(|(_, process)| ReturnValue::Value(Value::Object(process_dict(process))))
+        .collect::<VecDeque<_>>();
 
-        let list = list
-            .into_iter()
-            .map(|(_, process)| ReturnValue::Value(Value::Object(process_dict(process))))
-            .collect::<VecDeque<_>>();
-
-        Ok(list)
-    }
+    Ok(list)
 }

src/commands/reject.rs

@@ -1,28 +1,22 @@
 use crate::errors::ShellError;
-use crate::object::base::reject;
+use crate::object::base::reject_fields;
 use crate::object::Value;
 use crate::prelude::*;
-use derive_new::new;
 
-#[derive(new)]
-pub struct Reject;
-
-impl crate::Command for Reject {
-    fn run(&self, args: CommandArgs<'value>) -> Result<VecDeque<ReturnValue>, ShellError> {
-        if args.args.is_empty() {
-            return Err(ShellError::string("select requires a field"));
-        }
-
-        let fields: Result<Vec<String>, _> = args.args.iter().map(|a| a.as_string()).collect();
-        let fields = fields?;
-
-        let objects = args
-            .input
-            .iter()
-            .map(|item| Value::Object(reject(item, &fields)))
-            .map(|item| ReturnValue::Value(item))
-            .collect();
-
-        Ok(objects)
+pub fn reject(args: CommandArgs<'value>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    if args.args.is_empty() {
+        return Err(ShellError::string("select requires a field"));
     }
+
+    let fields: Result<Vec<String>, _> = args.args.iter().map(|a| a.as_string()).collect();
+    let fields = fields?;
+
+    let objects = args
+        .input
+        .iter()
+        .map(|item| Value::Object(reject_fields(item, &fields)))
+        .map(|item| ReturnValue::Value(item))
+        .collect();
+
+    Ok(objects)
 }

src/commands/select.rs

@@ -1,28 +1,22 @@
 use crate::errors::ShellError;
-use crate::object::base::select;
+use crate::object::base::select_fields;
 use crate::object::Value;
 use crate::prelude::*;
-use derive_new::new;
 
-#[derive(new)]
-pub struct Select;
-
-impl crate::Command for Select {
-    fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
-        if args.args.is_empty() {
-            return Err(ShellError::string("select requires a field"));
-        }
-
-        let fields: Result<Vec<String>, _> = args.args.iter().map(|a| a.as_string()).collect();
-        let fields = fields?;
-
-        let objects = args
-            .input
-            .iter()
-            .map(|item| Value::Object(select(item, &fields)))
-            .map(|item| ReturnValue::Value(item))
-            .collect();
-
-        Ok(objects)
+pub fn select(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    if args.args.is_empty() {
+        return Err(ShellError::string("select requires a field"));
     }
+
+    let fields: Result<Vec<String>, _> = args.args.iter().map(|a| a.as_string()).collect();
+    let fields = fields?;
+
+    let objects = args
+        .input
+        .iter()
+        .map(|item| Value::Object(select_fields(item, &fields)))
+        .map(|item| ReturnValue::Value(item))
+        .collect();
+
+    Ok(objects)
 }

src/commands/skip.rs

@@ -1,29 +1,21 @@
 use crate::errors::ShellError;
 use crate::prelude::*;
-use derive_new::new;
 
-#[derive(new)]
-pub struct Skip;
+pub fn skip(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    let amount = args.args[0].as_int()?;
 
-// TODO: "Amount remaining" wrapper
+    let amount = if args.input.len() > amount as usize {
+        amount as usize
+    } else {
+        args.input.len()
+    };
 
-impl crate::Command for Skip {
-    fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
-        let amount = args.args[0].as_int()?;
+    let out: VecDeque<ReturnValue> = args
+        .input
+        .into_iter()
+        .skip(amount)
+        .map(|v| ReturnValue::Value(v))
+        .collect();
 
-        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)
-    }
+    Ok(out)
 }

src/commands/sort_by.rs

@@ -1,29 +1,23 @@
 use crate::errors::ShellError;
 use crate::prelude::*;
-use derive_new::new;
 
-#[derive(new)]
-pub struct SortBy;
+pub fn sort_by(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    let fields: Result<Vec<_>, _> = args.args.iter().map(|a| a.as_string()).collect();
+    let fields = fields?;
 
-impl crate::Command for SortBy {
-    fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
-        let fields: Result<Vec<_>, _> = args.args.iter().map(|a| a.as_string()).collect();
-        let fields = fields?;
+    let mut output = args.input.into_iter().collect::<Vec<_>>();
 
-        let mut output = args.input.into_iter().collect::<Vec<_>>();
-
-        output.sort_by_key(|item| {
-            fields
-                .iter()
-                .map(|f| item.get_data_by_key(f).borrow().copy())
-                .collect::<Vec<Value>>()
-        });
-
-        let output = output
+    output.sort_by_key(|item| {
+        fields
             .iter()
-            .map(|o| ReturnValue::Value(o.copy()))
-            .collect();
+            .map(|f| item.get_data_by_key(f).borrow().copy())
+            .collect::<Vec<Value>>()
+    });
 
-        Ok(output)
-    }
+    let output = output
+        .iter()
+        .map(|o| ReturnValue::Value(o.copy()))
+        .collect();
+
+    Ok(output)
 }

src/commands/take.rs

@@ -1,29 +1,23 @@
 use crate::errors::ShellError;
 use crate::prelude::*;
-use derive_new::new;
-
-#[derive(new)]
-pub struct Take;
 
 // TODO: "Amount remaining" wrapper
 
-impl crate::Command for Take {
-    fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
-        let amount = args.args[0].as_int()?;
+pub fn take(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 amount = if args.input.len() > amount as usize {
+        amount as usize
+    } else {
+        args.input.len()
+    };
 
-        let out: VecDeque<ReturnValue> = args
-            .input
-            .into_iter()
-            .take(amount)
-            .map(|v| ReturnValue::Value(v))
-            .collect();
+    let out: VecDeque<ReturnValue> = args
+        .input
+        .into_iter()
+        .take(amount)
+        .map(|v| ReturnValue::Value(v))
+        .collect();
 
-        Ok(out)
-    }
+    Ok(out)
 }

src/commands/to_array.rs

@@ -1,19 +1,13 @@
 use crate::errors::ShellError;
 use crate::object::Value;
 use crate::prelude::*;
-use derive_new::new;
 
-#[derive(new)]
-pub struct ToArray;
-
-impl crate::Command for ToArray {
-    fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
-        let out = args.input.into_iter().collect();
-        Ok(ReturnValue::single(Value::List(out)))
-    }
+pub fn to_array(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    let out = args.input.into_iter().collect();
+    Ok(ReturnValue::single(Value::List(out)))
 }
 
-crate fn to_array(stream: VecDeque<Value>) -> VecDeque<Value> {
+crate fn stream_to_array(stream: VecDeque<Value>) -> VecDeque<Value> {
     let out = Value::List(stream.into_iter().collect());
     let mut stream = VecDeque::new();
     stream.push_back(out);

src/commands/view.rs

@@ -1,32 +1,26 @@
 use crate::errors::ShellError;
 use crate::prelude::*;
-use derive_new::new;
 use prettyprint::PrettyPrinter;
 
-#[derive(new)]
-pub struct View;
+pub fn view(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    let target = match args.args.first() {
+        // TODO: This needs better infra
+        None => return Err(ShellError::string(format!("cat must take one arg"))),
+        Some(v) => v.as_string()?.clone(),
+    };
 
-impl crate::Command for View {
-    fn run(&self, args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
-        let target = match args.args.first() {
-            // TODO: This needs better infra
-            None => return Err(ShellError::string(format!("cat must take one arg"))),
-            Some(v) => v.as_string()?.clone(),
-        };
+    let cwd = args.env.cwd().to_path_buf();
 
-        let cwd = args.env.cwd().to_path_buf();
+    let printer = PrettyPrinter::default()
+        .line_numbers(false)
+        .header(false)
+        .grid(false)
+        .build()
+        .map_err(|e| ShellError::string(e))?;
 
-        let printer = PrettyPrinter::default()
-            .line_numbers(false)
-            .header(false)
-            .grid(false)
-            .build()
-            .map_err(|e| ShellError::string(e))?;
+    let file = cwd.join(target);
 
-        let file = cwd.join(target);
+    let _ = printer.file(file.display().to_string());
 
-        let _ = printer.file(file.display().to_string());
-
-        Ok(VecDeque::new())
-    }
+    Ok(VecDeque::new())
 }

src/commands/where_.rs

@@ -1,35 +1,29 @@
 use crate::errors::ShellError;
 use crate::object::base::find;
 use crate::prelude::*;
-use derive_new::new;
 
-#[derive(new)]
-pub struct Where;
+pub fn r#where(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    if args.args.is_empty() {
+        return Err(ShellError::string("select requires a field"));
+    }
 
-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?;
+
+    match args.args[1] {
+        Value::Primitive(Primitive::Operator(ref operator)) => {
+            let objects = args
+                .input
+                .iter()
+                .filter(|item| find(&item, &field, operator, &args.args[2]))
+                .map(|item| ReturnValue::Value(item.copy()))
+                .collect();
+
+            Ok(objects)
         }
-
-        let field: Result<String, _> = args.args[0].as_string();
-        let field = field?;
-
-        match args.args[1] {
-            Value::Primitive(Primitive::Operator(ref operator)) => {
-                let objects = args
-                    .input
-                    .iter()
-                    .filter(|item| find(&item, &field, operator, &args.args[2]))
-                    .map(|item| ReturnValue::Value(item.copy()))
-                    .collect();
-
-                Ok(objects)
-            }
-            ref x => {
-                println!("{:?}", x);
-                Err(ShellError::string("expected a comparison operator"))
-            }
+        ref x => {
+            println!("{:?}", x);
+            Err(ShellError::string("expected a comparison operator"))
         }
     }
 }

src/context.rs

@@ -1,9 +1,10 @@
 use crate::prelude::*;
 
 use std::error::Error;
+use std::sync::Arc;
 
 pub struct Context {
-    commands: indexmap::IndexMap<String, Box<dyn crate::Command>>,
+    commands: indexmap::IndexMap<String, Arc<dyn crate::Command>>,
     crate host: Box<dyn crate::Host>,
     crate env: Environment,
 }
@@ -17,35 +18,33 @@ impl Context {
         })
     }
 
-    pub fn add_commands(&mut self, commands: Vec<(&str, Box<dyn crate::Command>)>) {
+    pub fn add_commands(&mut self, commands: Vec<(&str, Arc<dyn crate::Command>)>) {
         for (name, command) in commands {
             self.commands.insert(name.to_string(), command);
         }
     }
 
-    crate fn has_command(&mut self, name: &str) -> bool {
+    crate fn has_command(&self, name: &str) -> bool {
         self.commands.contains_key(name)
     }
 
+    crate fn get_command(&self, name: &str) -> Arc<dyn Command> {
+        self.commands.get(name).unwrap().clone()
+    }
+
     crate fn run_command(
-        &self,
-        name: &str,
+        &mut self,
+        command: Arc<dyn Command>,
         arg_list: Vec<Value>,
         input: VecDeque<Value>,
     ) -> Result<VecDeque<ReturnValue>, ShellError> {
         let command_args = CommandArgs {
-            host: &self.host,
+            host: &mut self.host,
             env: &self.env,
             args: arg_list,
             input,
         };
 
-        match self.commands.get(name) {
-            None => Err(ShellError::string(format!(
-                "Command {} did not exist",
-                name
-            ))),
-            Some(command) => command.run(command_args),
-        }
+        command.run(command_args)
     }
 }

src/format.rs

@@ -5,9 +5,6 @@ crate mod table;
 
 use crate::prelude::*;
 
-use crate::Context;
-use std::sync::{Arc, Mutex};
-
 crate use entries::{EntriesListView, EntriesView};
 crate use generic::GenericView;
 crate use table::TableView;
@@ -22,7 +19,7 @@ fn print_rendered(lines: &[String], host: &mut dyn Host) {
     }
 }
 
-crate fn print_view(view: &impl RenderView, context: Arc<Mutex<Context>>) {
-    let mut ctx = context.lock().unwrap();
-    crate::format::print_rendered(&view.render_view(&ctx.host), &mut ctx.host);
+crate fn print_view(view: &impl RenderView, host: &mut Host) {
+    // let mut ctx = context.lock().unwrap();
+    crate::format::print_rendered(&view.render_view(host), host);
 }

src/main.rs

@@ -14,8 +14,9 @@ mod parser;
 mod prelude;
 mod shell;
 
+use crate::commands::classified::{ClassifiedCommand, ExternalCommand, InternalCommand};
 use crate::commands::command::ReturnValue;
-crate use crate::commands::command::{Command, CommandAction, CommandBlueprint};
+crate use crate::commands::command::{Command, CommandAction};
 use crate::context::Context;
 crate use crate::env::{Environment, Host};
 crate use crate::errors::ShellError;
@@ -26,8 +27,7 @@ use rustyline::error::ReadlineError;
 use rustyline::{self, ColorMode, Config, Editor};
 use std::collections::VecDeque;
 use std::error::Error;
-use std::sync::{Arc, Mutex};
-use subprocess::Exec;
+use std::sync::Arc;
 
 #[derive(Debug)]
 pub enum MaybeOwned<'a, T> {
@@ -59,39 +59,38 @@ fn main() -> Result<(), Box<Error>> {
         println!("No previous history.");
     }
 
-    let context = Arc::new(Mutex::new(Context::basic()?));
+    let mut context = Context::basic()?;
 
     {
         use crate::commands::*;
 
-        context.lock().unwrap().add_commands(vec![
-            ("ps", Box::new(ps::Ps)),
-            ("ls", Box::new(ls::Ls)),
-            ("cd", Box::new(cd::Cd)),
-            ("view", Box::new(view::View)),
-            ("skip", Box::new(skip::Skip)),
-            ("take", Box::new(take::Take)),
-            ("select", Box::new(select::Select)),
-            ("reject", Box::new(reject::Reject)),
-            ("to-array", Box::new(to_array::ToArray)),
-            ("where", Box::new(where_::Where)),
-            ("sort-by", Box::new(sort_by::SortBy)),
+        context.add_commands(vec![
+            ("format", Arc::new(format)),
+            ("format-list", Arc::new(format_list)),
+            ("ps", Arc::new(ps::ps)),
+            ("ls", Arc::new(ls::ls)),
+            ("cd", Arc::new(cd::cd)),
+            ("view", Arc::new(view::view)),
+            ("skip", Arc::new(skip::skip)),
+            ("take", Arc::new(take::take)),
+            ("select", Arc::new(select::select)),
+            ("reject", Arc::new(reject::reject)),
+            ("to-array", Arc::new(to_array::to_array)),
+            ("where", Arc::new(where_::r#where)),
+            ("sort-by", Arc::new(sort_by::sort_by)),
         ]);
     }
 
     loop {
-        let readline = rl.readline(&format!(
-            "{}> ",
-            context.lock().unwrap().env.cwd().display().to_string()
-        ));
+        let readline = rl.readline(&format!("{}> ", context.env.cwd().display().to_string()));
 
-        match process_line(readline, context.clone()) {
+        match process_line(readline, &mut context) {
             LineResult::Success(line) => {
                 rl.add_history_entry(line.clone());
             }
 
             LineResult::Error(err) => {
-                context.lock().unwrap().host.stdout(&err);
+                context.host.stdout(&err);
             }
 
             LineResult::Break => {
@@ -100,8 +99,6 @@ fn main() -> Result<(), Box<Error>> {
 
             LineResult::FatalError(err) => {
                 context
-                    .lock()
-                    .unwrap()
                     .host
                     .stdout(&format!("A surprising fatal error occurred.\n{:?}", err));
             }
@@ -121,10 +118,7 @@ enum LineResult {
     FatalError(ShellError),
 }
 
-fn process_line(
-    readline: Result<String, ReadlineError>,
-    context: Arc<Mutex<Context>>,
-) -> LineResult {
+fn process_line(readline: Result<String, ReadlineError>, ctx: &mut Context) -> LineResult {
     match &readline {
         Ok(line) if line.trim() == "exit" => LineResult::Break,
 
@@ -144,11 +138,7 @@ fn process_line(
             let mut input = VecDeque::new();
 
             for item in parsed {
-                input = match process_command(
-                    item.clone(),
-                    input,
-                    context.clone(),
-                ) {
+                input = match process_command(item.clone(), input, ctx) {
                     Ok(val) => val,
                     Err(err) => return LineResult::Error(format!("{}", err.description())),
                 };
@@ -156,9 +146,18 @@ fn process_line(
 
             if input.len() > 0 {
                 if equal_shapes(&input) {
-                    format(crate::commands::to_array(input), context.clone());
+                    let array = crate::commands::stream_to_array(input);
+                    let args = CommandArgs::from_context(ctx, vec![], array);
+                    match format(args) {
+                        Ok(_) => {}
+                        Err(err) => return LineResult::Error(err.to_string()),
+                    }
                 } else {
-                    format(input, context.clone());
+                    let args = CommandArgs::from_context(ctx, vec![], input);
+                    match format(args) {
+                        Ok(_) => {}
+                        Err(err) => return LineResult::Error(err.to_string()),
+                    }
                 }
             }
 
@@ -182,69 +181,58 @@ fn process_line(
 fn process_command(
     parsed: Vec<crate::parser::Item>,
     input: VecDeque<Value>,
-    context: Arc<Mutex<Context>>,
+    context: &mut Context,
 ) -> Result<VecDeque<Value>, ShellError> {
-    let command = &parsed[0].name()?;
-    let arg_list = parsed[1..].iter().map(|i| i.as_value()).collect();
-    let arg_list_strings: Vec<String> = parsed[1..].iter().map(|i| i.print()).collect();
+    let command = classify_command(&parsed, context)?;
 
-    if command == &"format" {
-        format(input, context);
+    command.run(input, context)
+}
 
-        Ok(VecDeque::new())
-    } else if command == &"format-list" {
-        let view = EntriesListView::from_stream(input);
+fn classify_command(
+    command: &[crate::parser::Item],
+    context: &Context,
+) -> Result<ClassifiedCommand, ShellError> {
+    let command_name = &command[0].name()?;
 
-        crate::format::print_view(&view, context.clone());
+    let arg_list: Vec<Value> = command[1..].iter().map(|i| i.as_value()).collect();
+    let arg_list_strings: Vec<String> = command[1..].iter().map(|i| i.print()).collect();
 
-        Ok(VecDeque::new())
-    } else {
-        let mut ctx = context.lock().unwrap();
-
-        match ctx.has_command(*command) {
+    match *command_name {
+        other => match context.has_command(*command_name) {
             true => {
-                // let mut instance = ctx.create_command(command, arg_list)?;
-
-                let result = ctx.run_command(command, arg_list, input)?;
-
-                // let result = command.run(input_args)?;
-                let mut next = VecDeque::new();
-
-                for v in result {
-                    match v {
-                        ReturnValue::Action(action) => match action {
-                            crate::CommandAction::ChangeCwd(cwd) => ctx.env.cwd = cwd,
-                        },
-
-                        ReturnValue::Value(v) => next.push_back(v),
-                    }
-                }
-
-                Ok(next)
+                let command = context.get_command(command_name);
+                Ok(ClassifiedCommand::Internal(InternalCommand {
+                    command,
+                    args: arg_list,
+                }))
             }
-
-            false => {
-                Exec::shell(command)
-                    .args(&arg_list_strings)
-                    .cwd(ctx.env.cwd())
-                    .join()
-                    .unwrap();
-                Ok(VecDeque::new())
-            }
-        }
+            false => Ok(ClassifiedCommand::External(ExternalCommand {
+                name: other.to_string(),
+                args: arg_list_strings,
+            })),
+        },
     }
 }
 
-fn format(input: VecDeque<Value>, context: Arc<Mutex<Context>>) {
-    let last = input.len() - 1;
-    for (i, item) in input.iter().enumerate() {
+fn format(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    let last = args.input.len() - 1;
+    for (i, item) in args.input.iter().enumerate() {
         let view = GenericView::new(item);
-        crate::format::print_view(&view, context.clone());
+        crate::format::print_view(&view, args.host);
 
         if last != i {
             println!("");
         }
     }
+
+    Ok(VecDeque::new())
+}
+
+fn format_list(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    let view = EntriesListView::from_stream(args.input);
+    crate::format::print_view(&view, args.host);
+
+    Ok(VecDeque::new())
 }
 
 fn equal_shapes(input: &VecDeque<Value>) -> bool {

src/object/base.rs

@@ -1,11 +1,11 @@
 use crate::errors::ShellError;
 use crate::object::desc::DataDescriptor;
+use crate::parser::parse::Operator;
 use ansi_term::Color;
 use chrono::{DateTime, Utc};
 use chrono_humanize::Humanize;
 use ordered_float::OrderedFloat;
 use std::time::SystemTime;
-use crate::parser::parse::Operator;
 
 type OF64 = OrderedFloat<f64>;
 
@@ -50,7 +50,7 @@ impl Primitive {
                 (false, Some(_)) => format!(""),
             },
             Primitive::Date(d) => format!("{}", d.humanize()),
-            Primitive::Operator(o) => o.print()
+            Primitive::Operator(o) => o.print(),
         }
     }
 }
@@ -196,7 +196,7 @@ impl Value {
     }
 }
 
-crate fn select(obj: &Value, fields: &[String]) -> crate::object::Dictionary {
+crate fn select_fields(obj: &Value, fields: &[String]) -> crate::object::Dictionary {
     let mut out = crate::object::Dictionary::default();
 
     let descs = obj.data_descriptors();
@@ -211,7 +211,7 @@ crate fn select(obj: &Value, fields: &[String]) -> crate::object::Dictionary {
     out
 }
 
-crate fn reject(obj: &Value, fields: &[String]) -> crate::object::Dictionary {
+crate fn reject_fields(obj: &Value, fields: &[String]) -> crate::object::Dictionary {
     let mut out = crate::object::Dictionary::default();
 
     let descs = obj.data_descriptors();
@@ -243,18 +243,28 @@ crate fn find(obj: &Value, field: &str, op: &Operator, rhs: &Value) -> bool {
                 },
                 Value::Primitive(Primitive::Bytes(i)) => match (op, rhs) {
                     (Operator::LessThan, Value::Primitive(Primitive::Int(i2))) => i < (*i2 as u128),
-                    (Operator::GreaterThan, Value::Primitive(Primitive::Int(i2))) => i > (*i2 as u128),
-                    (Operator::LessThanOrEqual, Value::Primitive(Primitive::Int(i2))) => i <= (*i2 as u128),
-                    (Operator::GreaterThanOrEqual, Value::Primitive(Primitive::Int(i2))) => i >= (*i2 as u128),
+                    (Operator::GreaterThan, Value::Primitive(Primitive::Int(i2))) => {
+                        i > (*i2 as u128)
+                    }
+                    (Operator::LessThanOrEqual, Value::Primitive(Primitive::Int(i2))) => {
+                        i <= (*i2 as u128)
+                    }
+                    (Operator::GreaterThanOrEqual, Value::Primitive(Primitive::Int(i2))) => {
+                        i >= (*i2 as u128)
+                    }
                     (Operator::Equal, Value::Primitive(Primitive::Int(i2))) => i == (*i2 as u128),
-                    (Operator::NotEqual, Value::Primitive(Primitive::Int(i2))) => i != (*i2 as u128),
+                    (Operator::NotEqual, Value::Primitive(Primitive::Int(i2))) => {
+                        i != (*i2 as u128)
+                    }
                     _ => false,
                 },
                 Value::Primitive(Primitive::Int(i)) => match (op, rhs) {
                     (Operator::LessThan, Value::Primitive(Primitive::Int(i2))) => i < *i2,
                     (Operator::GreaterThan, Value::Primitive(Primitive::Int(i2))) => i > *i2,
                     (Operator::LessThanOrEqual, Value::Primitive(Primitive::Int(i2))) => i <= *i2,
-                    (Operator::GreaterThanOrEqual, Value::Primitive(Primitive::Int(i2))) => i >= *i2,
+                    (Operator::GreaterThanOrEqual, Value::Primitive(Primitive::Int(i2))) => {
+                        i >= *i2
+                    }
                     (Operator::Equal, Value::Primitive(Primitive::Int(i2))) => i == *i2,
                     (Operator::NotEqual, Value::Primitive(Primitive::Int(i2))) => i != *i2,
                     _ => false,
@@ -263,15 +273,29 @@ crate fn find(obj: &Value, field: &str, op: &Operator, rhs: &Value) -> bool {
                     (Operator::LessThan, Value::Primitive(Primitive::Float(i2))) => i < *i2,
                     (Operator::GreaterThan, Value::Primitive(Primitive::Float(i2))) => i > *i2,
                     (Operator::LessThanOrEqual, Value::Primitive(Primitive::Float(i2))) => i <= *i2,
-                    (Operator::GreaterThanOrEqual, Value::Primitive(Primitive::Float(i2))) => i >= *i2,
+                    (Operator::GreaterThanOrEqual, Value::Primitive(Primitive::Float(i2))) => {
+                        i >= *i2
+                    }
                     (Operator::Equal, Value::Primitive(Primitive::Float(i2))) => i == *i2,
                     (Operator::NotEqual, Value::Primitive(Primitive::Float(i2))) => i != *i2,
-                    (Operator::LessThan, Value::Primitive(Primitive::Int(i2))) => (i.into_inner()) < *i2 as f64,
-                    (Operator::GreaterThan, Value::Primitive(Primitive::Int(i2))) => i.into_inner() > *i2 as f64,
-                    (Operator::LessThanOrEqual, Value::Primitive(Primitive::Int(i2))) => i.into_inner() <= *i2 as f64,
-                    (Operator::GreaterThanOrEqual, Value::Primitive(Primitive::Int(i2))) => i.into_inner() >= *i2 as f64,
-                    (Operator::Equal, Value::Primitive(Primitive::Int(i2))) => i.into_inner() == *i2 as f64,
-                    (Operator::NotEqual, Value::Primitive(Primitive::Int(i2))) => i.into_inner() != *i2 as f64,
+                    (Operator::LessThan, Value::Primitive(Primitive::Int(i2))) => {
+                        (i.into_inner()) < *i2 as f64
+                    }
+                    (Operator::GreaterThan, Value::Primitive(Primitive::Int(i2))) => {
+                        i.into_inner() > *i2 as f64
+                    }
+                    (Operator::LessThanOrEqual, Value::Primitive(Primitive::Int(i2))) => {
+                        i.into_inner() <= *i2 as f64
+                    }
+                    (Operator::GreaterThanOrEqual, Value::Primitive(Primitive::Int(i2))) => {
+                        i.into_inner() >= *i2 as f64
+                    }
+                    (Operator::Equal, Value::Primitive(Primitive::Int(i2))) => {
+                        i.into_inner() == *i2 as f64
+                    }
+                    (Operator::NotEqual, Value::Primitive(Primitive::Int(i2))) => {
+                        i.into_inner() != *i2 as f64
+                    }
 
                     _ => false,
                 },

src/parser/completer.rs

@@ -3,7 +3,7 @@ use std::collections::BTreeMap;
 
 #[allow(unused)]
 crate struct Completer {
-    commands: BTreeMap<String, Box<dyn crate::CommandBlueprint>>,
+    commands: BTreeMap<String, Box<dyn crate::Command>>,
 }
 
 impl completion::Completer for Completer {

src/prelude.rs

@@ -1,4 +1,4 @@
-crate use crate::commands::command::{CommandArgs, ReturnValue};
+crate use crate::commands::command::{Command, CommandArgs, ReturnValue};
 crate use crate::env::{Environment, Host};
 crate use crate::errors::ShellError;
 crate use crate::object::{Primitive, Value};