Merge pull request #1 from mat-1/brigadier

azalea-brigadier

52 files changed, 2841 insertions, 0 deletions

diff --git a/Cargo.lock b/Cargo.lock
index eca4d4fa..67259fef 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -68,6 +68,10 @@ dependencies = [
 ]
 
 [[package]]
+name = "azalea-brigadier"
+version = "0.1.0"
+
+[[package]]
 name = "azalea-chat"
 version = "0.1.0"
 dependencies = [
diff --git a/Cargo.toml b/Cargo.toml
index d22c326b..7f958207 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,4 +8,5 @@ members = [
   "azalea-core",
   "azalea-auth",
   "azalea-nbt",
+  "azalea-brigadier",
 ]
diff --git a/azalea-brigadier/Cargo.toml b/azalea-brigadier/Cargo.toml
new file mode 100644
index 00000000..a7ebf618
--- /dev/null
+++ b/azalea-brigadier/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+edition = "2021"
+name = "azalea-brigadier"
+version = "0.1.0"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/azalea-brigadier/README.md b/azalea-brigadier/README.md
new file mode 100644
index 00000000..a7318566
--- /dev/null
+++ b/azalea-brigadier/README.md
@@ -0,0 +1,3 @@
+# Azalea Brigadier
+
+A Rust port of Mojang's [Brigadier](https://github.com/Mojang/brigadier) command parsing and dispatching library.
diff --git a/azalea-brigadier/src/arguments/argument_type.rs b/azalea-brigadier/src/arguments/argument_type.rs
new file mode 100644
index 00000000..029e4696
--- /dev/null
+++ b/azalea-brigadier/src/arguments/argument_type.rs
@@ -0,0 +1,7 @@
+use std::{any::Any, rc::Rc};
+
+use crate::{exceptions::CommandSyntaxException, string_reader::StringReader};
+
+pub trait ArgumentType {
+    fn parse(&self, reader: &mut StringReader) -> Result<Rc<dyn Any>, CommandSyntaxException>;
+}
diff --git a/azalea-brigadier/src/arguments/integer_argument_type.rs b/azalea-brigadier/src/arguments/integer_argument_type.rs
new file mode 100644
index 00000000..336046a7
--- /dev/null
+++ b/azalea-brigadier/src/arguments/integer_argument_type.rs
@@ -0,0 +1,54 @@
+use std::{any::Any, rc::Rc};
+
+use crate::{
+    context::CommandContext,
+    exceptions::{BuiltInExceptions, CommandSyntaxException},
+    string_reader::StringReader,
+};
+
+use super::ArgumentType;
+
+#[derive(Default)]
+struct Integer {
+    pub minimum: Option<i32>,
+    pub maximum: Option<i32>,
+}
+
+impl ArgumentType for Integer {
+    fn parse(&self, reader: &mut StringReader) -> Result<Rc<dyn Any>, CommandSyntaxException> {
+        let start = reader.cursor;
+        let result = reader.read_int()?;
+        if let Some(minimum) = self.minimum {
+            if result < minimum {
+                reader.cursor = start;
+                return Err(BuiltInExceptions::IntegerTooSmall {
+                    found: result,
+                    min: minimum,
+                }
+                .create_with_context(reader));
+            }
+        }
+        if let Some(maximum) = self.maximum {
+            if result > maximum {
+                reader.cursor = start;
+                return Err(BuiltInExceptions::IntegerTooBig {
+                    found: result,
+                    max: maximum,
+                }
+                .create_with_context(reader));
+            }
+        }
+        Ok(Rc::new(result))
+    }
+}
+
+pub fn integer() -> impl ArgumentType {
+    Integer::default()
+}
+pub fn get_integer<S>(context: &CommandContext<S>, name: &str) -> Option<i32> {
+    context
+        .argument(name)
+        .unwrap()
+        .downcast_ref::<i32>()
+        .copied()
+}
diff --git a/azalea-brigadier/src/arguments/mod.rs b/azalea-brigadier/src/arguments/mod.rs
new file mode 100644
index 00000000..dec39297
--- /dev/null
+++ b/azalea-brigadier/src/arguments/mod.rs
@@ -0,0 +1,4 @@
+mod argument_type;
+pub mod integer_argument_type;
+
+pub use argument_type::ArgumentType;
diff --git a/azalea-brigadier/src/builder/argument_builder.rs b/azalea-brigadier/src/builder/argument_builder.rs
new file mode 100644
index 00000000..d26b2a8a
--- /dev/null
+++ b/azalea-brigadier/src/builder/argument_builder.rs
@@ -0,0 +1,137 @@
+use crate::{context::CommandContext, modifier::RedirectModifier, tree::CommandNode};
+
+use super::{literal_argument_builder::Literal, required_argument_builder::Argument};
+use std::{cell::RefCell, fmt::Debug, rc::Rc};
+
+#[derive(Debug, Clone)]
+pub enum ArgumentBuilderType {
+    Literal(Literal),
+    Argument(Argument),
+}
+
+/// A node that hasn't yet been built.
+pub struct ArgumentBuilder<S> {
+    arguments: CommandNode<S>,
+
+    command: Option<Rc<dyn Fn(&CommandContext<S>) -> i32>>,
+    requirement: Rc<dyn Fn(Rc<S>) -> bool>,
+    target: Option<Rc<RefCell<CommandNode<S>>>>,
+
+    forks: bool,
+    modifier: Option<Rc<RedirectModifier<S>>>,
+}
+
+impl<S> Clone for ArgumentBuilder<S> {
+    fn clone(&self) -> Self {
+        Self {
+            arguments: self.arguments.clone(),
+            command: self.command.clone(),
+            requirement: self.requirement.clone(),
+            target: self.target.clone(),
+            forks: self.forks,
+            modifier: self.modifier.clone(),
+        }
+    }
+}
+
+/// A node that isn't yet built.
+impl<S> ArgumentBuilder<S> {
+    pub fn new(value: ArgumentBuilderType) -> Self {
+        Self {
+            arguments: CommandNode {
+                value,
+                ..Default::default()
+            },
+            command: None,
+            requirement: Rc::new(|_| true),
+            forks: false,
+            modifier: None,
+            target: None,
+        }
+    }
+
+    pub fn then(&mut self, argument: ArgumentBuilder<S>) -> Self {
+        self.then_built(argument.build())
+    }
+
+    pub fn then_built(&mut self, argument: CommandNode<S>) -> Self {
+        self.arguments.add_child(&Rc::new(RefCell::new(argument)));
+        self.clone()
+    }
+
+    pub fn executes<F>(&mut self, f: F) -> Self
+    where
+        F: Fn(&CommandContext<S>) -> i32 + 'static,
+    {
+        self.command = Some(Rc::new(f));
+        self.clone()
+    }
+
+    pub fn requires<F>(&mut self, requirement: F) -> Self
+    where
+        F: Fn(Rc<S>) -> bool + 'static,
+    {
+        self.requirement = Rc::new(requirement);
+        self.clone()
+    }
+
+    pub fn redirect(&mut self, target: Rc<RefCell<CommandNode<S>>>) -> Self {
+        self.forward(target, None, false)
+    }
+
+    pub fn fork(
+        &mut self,
+        target: Rc<RefCell<CommandNode<S>>>,
+        modifier: Rc<RedirectModifier<S>>,
+    ) -> Self {
+        self.forward(target, Some(modifier), true)
+    }
+
+    pub fn forward(
+        &mut self,
+        target: Rc<RefCell<CommandNode<S>>>,
+        modifier: Option<Rc<RedirectModifier<S>>>,
+        fork: bool,
+    ) -> Self {
+        if !self.arguments.children.is_empty() {
+            panic!("Cannot forward a node with children");
+        }
+        self.target = Some(target);
+        self.modifier = modifier;
+        self.forks = fork;
+        self.clone()
+    }
+
+    pub fn build(self) -> CommandNode<S> {
+        let mut result = CommandNode {
+            value: self.arguments.value,
+            command: self.command,
+            requirement: self.requirement,
+            redirect: self.target,
+            modifier: self.modifier,
+            forks: self.forks,
+            arguments: Default::default(),
+            children: Default::default(),
+            literals: Default::default(),
+        };
+
+        for argument in self.arguments.children.values() {
+            result.add_child(argument);
+        }
+
+        result
+    }
+}
+
+impl<S> Debug for ArgumentBuilder<S> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("ArgumentBuilder")
+            .field("arguments", &self.arguments)
+            // .field("command", &self.command)
+            // .field("requirement", &self.requirement)
+            .field("target", &self.target)
+            .field("forks", &self.forks)
+            // .field("modifier", &self.modifier)
+            .finish()
+    }
+}
diff --git a/azalea-brigadier/src/builder/literal_argument_builder.rs b/azalea-brigadier/src/builder/literal_argument_builder.rs
new file mode 100644
index 00000000..6627ffdc
--- /dev/null
+++ b/azalea-brigadier/src/builder/literal_argument_builder.rs
@@ -0,0 +1,24 @@
+use super::argument_builder::{ArgumentBuilder, ArgumentBuilderType};
+
+#[derive(Debug, Clone, Default)]
+pub struct Literal {
+    pub value: String,
+}
+impl Literal {
+    pub fn new(value: &str) -> Self {
+        Self {
+            value: value.to_string(),
+        }
+    }
+}
+
+impl From<Literal> for ArgumentBuilderType {
+    fn from(literal: Literal) -> Self {
+        Self::Literal(literal)
+    }
+}
+
+/// Shortcut for creating a new literal builder node.
+pub fn literal<S>(value: &str) -> ArgumentBuilder<S> {
+    ArgumentBuilder::new(ArgumentBuilderType::Literal(Literal::new(value)))
+}
diff --git a/azalea-brigadier/src/builder/mod.rs b/azalea-brigadier/src/builder/mod.rs
new file mode 100644
index 00000000..26f2f644
--- /dev/null
+++ b/azalea-brigadier/src/builder/mod.rs
@@ -0,0 +1,3 @@
+pub mod argument_builder;
+pub mod literal_argument_builder;
+pub mod required_argument_builder;
diff --git a/azalea-brigadier/src/builder/required_argument_builder.rs b/azalea-brigadier/src/builder/required_argument_builder.rs
new file mode 100644
index 00000000..9d4d9e0a
--- /dev/null
+++ b/azalea-brigadier/src/builder/required_argument_builder.rs
@@ -0,0 +1,45 @@
+use super::argument_builder::{ArgumentBuilder, ArgumentBuilderType};
+use crate::{
+    arguments::ArgumentType, exceptions::CommandSyntaxException, string_reader::StringReader,
+};
+use std::{any::Any, fmt::Debug, rc::Rc};
+
+/// An argument node type. The `T` type parameter is the type of the argument,
+/// which can be anything.
+#[derive(Clone)]
+pub struct Argument {
+    pub name: String,
+    parser: Rc<dyn ArgumentType>,
+}
+impl Argument {
+    pub fn new(name: &str, parser: Rc<dyn ArgumentType>) -> Self {
+        Self {
+            name: name.to_string(),
+            parser,
+        }
+    }
+
+    pub fn parse(&self, reader: &mut StringReader) -> Result<Rc<dyn Any>, CommandSyntaxException> {
+        self.parser.parse(reader)
+    }
+}
+
+impl From<Argument> for ArgumentBuilderType {
+    fn from(argument: Argument) -> Self {
+        Self::Argument(argument)
+    }
+}
+
+impl Debug for Argument {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("Argument")
+            .field("name", &self.name)
+            // .field("parser", &self.parser)
+            .finish()
+    }
+}
+
+/// Shortcut for creating a new argument builder node.
+pub fn argument<S>(name: &str, parser: impl ArgumentType + 'static) -> ArgumentBuilder<S> {
+    ArgumentBuilder::new(Argument::new(name, Rc::new(parser)).into())
+}
diff --git a/azalea-brigadier/src/command_dispatcher.rs b/azalea-brigadier/src/command_dispatcher.rs
new file mode 100644
index 00000000..eab42dd8
--- /dev/null
+++ b/azalea-brigadier/src/command_dispatcher.rs
@@ -0,0 +1,298 @@
+use crate::{
+    builder::argument_builder::ArgumentBuilder,
+    context::{CommandContext, CommandContextBuilder},
+    exceptions::{BuiltInExceptions, CommandSyntaxException},
+    parse_results::ParseResults,
+    string_reader::StringReader,
+    tree::CommandNode,
+};
+use std::{cell::RefCell, cmp::Ordering, collections::HashMap, marker::PhantomData, mem, rc::Rc};
+
+#[derive(Default)]
+pub struct CommandDispatcher<S> {
+    pub root: Rc<RefCell<CommandNode<S>>>,
+    _marker: PhantomData<S>,
+}
+
+impl<S> CommandDispatcher<S> {
+    pub fn new() -> Self {
+        Self {
+            root: Rc::new(RefCell::new(CommandNode::default())),
+            _marker: PhantomData,
+        }
+    }
+
+    pub fn register(&mut self, node: ArgumentBuilder<S>) -> Rc<RefCell<CommandNode<S>>> {
+        let build = Rc::new(RefCell::new(node.build()));
+        self.root.borrow_mut().add_child(&build);
+        build
+    }
+
+    pub fn parse(&self, command: StringReader, source: Rc<S>) -> ParseResults<S> {
+        let context = CommandContextBuilder::new(
+            Rc::new(self.clone()),
+            source,
+            self.root.clone(),
+            command.cursor(),
+        );
+        self.parse_nodes(&self.root, &command, context).unwrap()
+    }
+
+    fn parse_nodes(
+        &self,
+        node: &Rc<RefCell<CommandNode<S>>>,
+        original_reader: &StringReader,
+        context_so_far: CommandContextBuilder<S>,
+    ) -> Result<ParseResults<S>, CommandSyntaxException> {
+        let source = context_so_far.source.clone();
+        let mut errors = HashMap::<Rc<CommandNode<S>>, CommandSyntaxException>::new();
+        let mut potentials: Vec<ParseResults<S>> = vec![];
+        let cursor = original_reader.cursor();
+
+        for child in node
+            .borrow()
+            .get_relevant_nodes(&mut original_reader.clone())
+        {
+            if !child.borrow().can_use(source.clone()) {
+                continue;
+            }
+            let mut context = context_so_far.clone();
+            let mut reader = original_reader.clone();
+
+            let parse_with_context_result =
+                child.borrow().parse_with_context(&mut reader, &mut context);
+            if let Err(ex) = parse_with_context_result {
+                errors.insert(
+                    Rc::new((*child.borrow()).clone()),
+                    BuiltInExceptions::DispatcherParseException {
+                        message: ex.message(),
+                    }
+                    .create_with_context(&reader),
+                );
+                reader.cursor = cursor;
+                continue;
+            }
+            if reader.can_read() && reader.peek() != ' ' {
+                errors.insert(
+                    Rc::new((*child.borrow()).clone()),
+                    BuiltInExceptions::DispatcherExpectedArgumentSeparator
+                        .create_with_context(&reader),
+                );
+                reader.cursor = cursor;
+                continue;
+            }
+
+            context.with_command(&child.borrow().command);
+            if reader.can_read_length(if child.borrow().redirect.is_none() {
+                2
+            } else {
+                1
+            }) {
+                reader.skip();
+                if let Some(redirect) = &child.borrow().redirect {
+                    let child_context = CommandContextBuilder::new(
+                        Rc::new(self.clone()),
+                        source,
+                        redirect.clone(),
+                        reader.cursor,
+                    );
+                    let parse = self
+                        .parse_nodes(redirect, &reader, child_context)
+                        .expect("Parsing nodes failed");
+                    context.with_child(Rc::new(parse.context));
+                    return Ok(ParseResults {
+                        context,
+                        reader: parse.reader,
+                        exceptions: parse.exceptions,
+                    });
+                } else {
+                    let parse = self
+                        .parse_nodes(&child, &reader, context)
+                        .expect("Parsing nodes failed");
+                    potentials.push(parse);
+                }
+            } else {
+                potentials.push(ParseResults {
+                    context,
+                    reader,
+                    exceptions: HashMap::new(),
+                });
+            }
+        }
+
+        if !potentials.is_empty() {
+            if potentials.len() > 1 {
+                potentials.sort_by(|a, b| {
+                    if !a.reader.can_read() && b.reader.can_read() {
+                        return Ordering::Less;
+                    };
+                    if a.reader.can_read() && !b.reader.can_read() {
+                        return Ordering::Greater;
+                    };
+                    if a.exceptions.is_empty() && !b.exceptions.is_empty() {
+                        return Ordering::Less;
+                    };
+                    if !a.exceptions.is_empty() && b.exceptions.is_empty() {
+                        return Ordering::Greater;
+                    };
+                    Ordering::Equal
+                })
+            }
+            let best_potential = potentials.into_iter().next().unwrap();
+            return Ok(best_potential);
+        }
+
+        Ok(ParseResults {
+            context: context_so_far,
+            reader: original_reader.clone(),
+            exceptions: errors,
+        })
+    }
+
+    pub fn execute(
+        &self,
+        input: StringReader,
+        source: Rc<S>,
+    ) -> Result<i32, CommandSyntaxException> {
+        let parse = self.parse(input, source);
+        Self::execute_parsed(parse)
+    }
+
+    pub fn add_paths(
+        &self,
+        node: Rc<RefCell<CommandNode<S>>>,
+        result: &mut Vec<Vec<Rc<RefCell<CommandNode<S>>>>>,
+        parents: Vec<Rc<RefCell<CommandNode<S>>>>,
+    ) {
+        let mut current = parents;
+        current.push(node.clone());
+        result.push(current.clone());
+
+        for child in node.borrow().children.values() {
+            self.add_paths(child.clone(), result, current.clone());
+        }
+    }
+
+    pub fn get_path(&self, target: CommandNode<S>) -> Vec<String> {
+        let rc_target = Rc::new(RefCell::new(target));
+        let mut nodes: Vec<Vec<Rc<RefCell<CommandNode<S>>>>> = Vec::new();
+        self.add_paths(self.root.clone(), &mut nodes, vec![]);
+
+        for list in nodes {
+            if *list.last().expect("Nothing in list").borrow() == *rc_target.borrow() {
+                let mut result: Vec<String> = Vec::with_capacity(list.len());
+                for node in list {
+                    if node != self.root {
+                        result.push(node.borrow().name().to_string());
+                    }
+                }
+                return result;
+            }
+        }
+        vec![]
+    }
+
+    pub fn find_node(&self, path: &[&str]) -> Option<Rc<RefCell<CommandNode<S>>>> {
+        let mut node = self.root.clone();
+        for name in path {
+            if let Some(child) = node.clone().borrow().child(name) {
+                node = child
+            } else {
+                return None;
+            }
+        }
+        Some(node)
+    }
+
+    /// Executes a given pre-parsed command.
+    pub fn execute_parsed(parse: ParseResults<S>) -> Result<i32, CommandSyntaxException> {
+        if parse.reader.can_read() {
+            if parse.exceptions.len() == 1 {
+                return Err(parse.exceptions.values().next().unwrap().clone());
+            }
+            if parse.context.range.is_empty() {
+                return Err(
+                    BuiltInExceptions::DispatcherUnknownCommand.create_with_context(&parse.reader)
+                );
+            }
+            return Err(
+                BuiltInExceptions::DispatcherUnknownArgument.create_with_context(&parse.reader)
+            );
+        }
+        let mut result = 0i32;
+        let mut successful_forks = 0;
+        let mut forked = false;
+        let mut found_command = false;
+        let command = parse.reader.string();
+        let original = parse.context.build(command);
+        let mut contexts = vec![original];
+        let mut next: Vec<CommandContext<S>> = vec![];
+
+        while !contexts.is_empty() {
+            for context in contexts.iter() {
+                let child = &context.child;
+                if let Some(child) = child {
+                    println!("aaaaaaa {:?}", child);
+                    forked |= child.forks;
+                    if child.has_nodes() {
+                        found_command = true;
+                        let modifier = &context.modifier;
+                        if let Some(modifier) = modifier {
+                            let results = modifier(context);
+                            if let Ok(results) = results {
+                                if !results.is_empty() {
+                                    next.extend(results.iter().map(|s| child.copy_for(s.clone())));
+                                }
+                            } else {
+                                // TODO
+                                // self.consumer.on_command_complete(context, false, 0);
+                                if !forked {
+                                    return Err(results.err().unwrap());
+                                }
+                            }
+                        } else {
+                            next.push(child.copy_for(context.source.clone()));
+                        }
+                    }
+                } else if let Some(context_command) = &context.command {
+                    found_command = true;
+
+                    let value = context_command(context);
+                    result += value;
+                    // consumer.on_command_complete(context, true, value);
+                    successful_forks += 1;
+
+                    // TODO: allow context_command to error and handle those errors
+                }
+            }
+
+            // move next into contexts and clear next
+            mem::swap(&mut contexts, &mut next);
+            next.clear();
+        }
+
+        if !found_command {
+            // consumer.on_command_complete(original, false, 0);
+            return Err(
+                BuiltInExceptions::DispatcherUnknownCommand.create_with_context(&parse.reader)
+            );
+        }
+
+        // TODO: this is not how vanilla does it but it works
+        Ok(if successful_forks >= 2 {
+            successful_forks
+        } else {
+            result
+        })
+        // Ok(if forked { successful_forks } else { result })
+    }
+}
+
+impl<S> Clone for CommandDispatcher<S> {
+    fn clone(&self) -> Self {
+        Self {
+            root: self.root.clone(),
+            _marker: PhantomData,
+        }
+    }
+}
diff --git a/azalea-brigadier/src/context/command_context.rs b/azalea-brigadier/src/context/command_context.rs
new file mode 100644
index 00000000..1834a73d
--- /dev/null
+++ b/azalea-brigadier/src/context/command_context.rs
@@ -0,0 +1,80 @@
+use super::{parsed_command_node::ParsedCommandNode, string_range::StringRange, ParsedArgument};
+use crate::{modifier::RedirectModifier, tree::CommandNode};
+use std::{any::Any, cell::RefCell, collections::HashMap, fmt::Debug, rc::Rc};
+
+/// A built `CommandContextBuilder`.
+pub struct CommandContext<S> {
+    pub source: Rc<S>,
+    pub input: String,
+    pub arguments: HashMap<String, ParsedArgument>,
+    pub command: Option<Rc<dyn Fn(&CommandContext<S>) -> i32>>,
+    pub root_node: Rc<RefCell<CommandNode<S>>>,
+    pub nodes: Vec<ParsedCommandNode<S>>,
+    pub range: StringRange,
+    pub child: Option<Rc<CommandContext<S>>>,
+    pub modifier: Option<Rc<RedirectModifier<S>>>,
+    pub forks: bool,
+}
+
+impl<S> Clone for CommandContext<S> {
+    fn clone(&self) -> Self {
+        Self {
+            source: self.source.clone(),
+            input: self.input.clone(),
+            arguments: self.arguments.clone(),
+            command: self.command.clone(),
+            root_node: self.root_node.clone(),
+            nodes: self.nodes.clone(),
+            range: self.range.clone(),
+            child: self.child.clone(),
+            modifier: self.modifier.clone(),
+            forks: self.forks,
+        }
+    }
+}
+
+impl<S> Debug for CommandContext<S> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("CommandContext")
+            // .field("source", &self.source)
+            .field("input", &self.input)
+            // .field("arguments", &self.arguments)
+            // .field("command", &self.command)
+            // .field("root_node", &self.root_node)
+            // .field("nodes", &self.nodes)
+            .field("range", &self.range)
+            .field("child", &self.child)
+            // .field("modifier", &self.modifier)
+            .field("forks", &self.forks)
+            .finish()
+    }
+}
+
+impl<S> CommandContext<S> {
+    pub fn copy_for(&self, source: Rc<S>) -> Self {
+        if Rc::ptr_eq(&source, &self.source) {
+            return self.clone();
+        }
+        CommandContext {
+            source,
+            input: self.input.clone(),
+            arguments: self.arguments.clone(),
+            command: self.command.clone(),
+            root_node: self.root_node.clone(),
+            nodes: self.nodes.clone(),
+            range: self.range.clone(),
+            child: self.child.clone(),
+            modifier: self.modifier.clone(),
+            forks: self.forks,
+        }
+    }
+
+    pub fn has_nodes(&self) -> bool {
+        !self.nodes.is_empty()
+    }
+
+    pub fn argument(&self, name: &str) -> Option<Rc<dyn Any>> {
+        let argument = self.arguments.get(name);
+        argument.map(|a| a.result.clone())
+    }
+}
diff --git a/azalea-brigadier/src/context/command_context_builder.rs b/azalea-brigadier/src/context/command_context_builder.rs
new file mode 100644
index 00000000..f192f6b7
--- /dev/null
+++ b/azalea-brigadier/src/context/command_context_builder.rs
@@ -0,0 +1,116 @@
+use super::{
+    command_context::CommandContext, parsed_command_node::ParsedCommandNode,
+    string_range::StringRange, ParsedArgument,
+};
+use crate::{command_dispatcher::CommandDispatcher, modifier::RedirectModifier, tree::CommandNode};
+use std::{cell::RefCell, collections::HashMap, fmt::Debug, rc::Rc};
+
+pub struct CommandContextBuilder<S> {
+    pub arguments: HashMap<String, ParsedArgument>,
+    pub root: Rc<RefCell<CommandNode<S>>>,
+    pub nodes: Vec<ParsedCommandNode<S>>,
+    pub dispatcher: Rc<CommandDispatcher<S>>,
+    pub source: Rc<S>,
+    pub command: Option<Rc<dyn Fn(&CommandContext<S>) -> i32>>,
+    pub child: Option<Rc<CommandContextBuilder<S>>>,
+    pub range: StringRange,
+    pub modifier: Option<Rc<RedirectModifier<S>>>,
+    pub forks: bool,
+}
+
+impl<S> Clone for CommandContextBuilder<S> {
+    fn clone(&self) -> Self {
+        Self {
+            arguments: self.arguments.clone(),
+            root: self.root.clone(),
+            nodes: self.nodes.clone(),
+            dispatcher: self.dispatcher.clone(),
+            source: self.source.clone(),
+            command: self.command.clone(),
+            child: self.child.clone(),
+            range: self.range.clone(),
+            modifier: self.modifier.clone(),
+            forks: self.forks,
+        }
+    }
+}
+
+impl<S> CommandContextBuilder<S> {
+    pub fn new(
+        dispatcher: Rc<CommandDispatcher<S>>,
+        source: Rc<S>,
+        root_node: Rc<RefCell<CommandNode<S>>>,
+        start: usize,
+    ) -> Self {
+        Self {
+            arguments: HashMap::new(),
+            root: root_node,
+            source,
+            range: StringRange::at(start),
+            command: None,
+            dispatcher,
+            nodes: vec![],
+            child: None,
+            modifier: None,
+            forks: false,
+        }
+    }
+
+    pub fn with_command(
+        &mut self,
+        command: &Option<Rc<dyn Fn(&CommandContext<S>) -> i32>>,
+    ) -> &Self {
+        self.command = command.clone();
+        self
+    }
+    pub fn with_child(&mut self, child: Rc<CommandContextBuilder<S>>) -> &Self {
+        self.child = Some(child);
+        self
+    }
+    pub fn with_argument(&mut self, name: &str, argument: ParsedArgument) -> &Self {
+        self.arguments.insert(name.to_string(), argument);
+        self
+    }
+    pub fn with_node(&mut self, node: Rc<RefCell<CommandNode<S>>>, range: StringRange) -> &Self {
+        self.nodes.push(ParsedCommandNode {
+            node: node.clone(),
+            range: range.clone(),
+        });
+        self.range = StringRange::encompassing(&self.range, &range);
+        self.modifier = node.borrow().modifier.clone();
+        self.forks = node.borrow().forks;
+        self
+    }
+
+    pub fn build(&self, input: &str) -> CommandContext<S> {
+        CommandContext {
+            arguments: self.arguments.clone(),
+            root_node: self.root.clone(),
+            nodes: self.nodes.clone(),
+            source: self.source.clone(),
+            command: self.command.clone(),
+            child: self.child.clone().map(|c| Rc::new(c.build(input))),
+            range: self.range.clone(),
+            forks: self.forks,
+            modifier: self.modifier.clone(),
+            input: input.to_string(),
+        }
+    }
+}
+
+impl<S> Debug for CommandContextBuilder<S> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("CommandContextBuilder")
+            // .field("arguments", &self.arguments)
+            .field("root", &self.root)
+            // .field("nodes", &self.nodes)
+            // .field("dispatcher", &self.dispatcher)
+            // .field("source", &self.source)
+            // .field("command", &self.command)
+            .field("child", &self.child)
+            .field("range", &self.range)
+            // .field("modifier", &self.modifier)
+            .field("forks", &self.forks)
+            .finish()
+    }
+}
diff --git a/azalea-brigadier/src/context/mod.rs b/azalea-brigadier/src/context/mod.rs
new file mode 100644
index 00000000..d535602a
--- /dev/null
+++ b/azalea-brigadier/src/context/mod.rs
@@ -0,0 +1,11 @@
+mod command_context;
+mod command_context_builder;
+mod parsed_argument;
+mod parsed_command_node;
+mod string_range;
+
+pub use command_context::CommandContext;
+pub use command_context_builder::CommandContextBuilder;
+pub use parsed_argument::ParsedArgument;
+pub use parsed_command_node::ParsedCommandNode;
+pub use string_range::StringRange;
diff --git a/azalea-brigadier/src/context/parsed_argument.rs b/azalea-brigadier/src/context/parsed_argument.rs
new file mode 100644
index 00000000..3302b1be
--- /dev/null
+++ b/azalea-brigadier/src/context/parsed_argument.rs
@@ -0,0 +1,8 @@
+use super::string_range::StringRange;
+use std::{any::Any, rc::Rc};
+
+#[derive(Clone)]
+pub struct ParsedArgument {
+    pub range: StringRange,
+    pub result: Rc<dyn Any>,
+}
diff --git a/azalea-brigadier/src/context/parsed_command_node.rs b/azalea-brigadier/src/context/parsed_command_node.rs
new file mode 100644
index 00000000..ed49928d
--- /dev/null
+++ b/azalea-brigadier/src/context/parsed_command_node.rs
@@ -0,0 +1,18 @@
+use super::string_range::StringRange;
+use crate::tree::CommandNode;
+use std::{cell::RefCell, rc::Rc};
+
+#[derive(Debug)]
+pub struct ParsedCommandNode<S> {
+    pub node: Rc<RefCell<CommandNode<S>>>,
+    pub range: StringRange,
+}
+
+impl<S> Clone for ParsedCommandNode<S> {
+    fn clone(&self) -> Self {
+        Self {
+            node: self.node.clone(),
+            range: self.range.clone(),
+        }
+    }
+}
diff --git a/azalea-brigadier/src/context/string_range.rs b/azalea-brigadier/src/context/string_range.rs
new file mode 100644
index 00000000..8ca88624
--- /dev/null
+++ b/azalea-brigadier/src/context/string_range.rs
@@ -0,0 +1,45 @@
+use std::cmp;
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Default)]
+pub struct StringRange {
+    start: usize,
+    end: usize,
+}
+
+impl StringRange {
+    pub fn new(start: usize, end: usize) -> Self {
+        Self { start, end }
+    }
+
+    pub fn at(pos: usize) -> Self {
+        Self::new(pos, pos)
+    }
+
+    pub fn between(start: usize, end: usize) -> Self {
+        Self::new(start, end)
+    }
+
+    pub fn encompassing(a: &Self, b: &Self) -> Self {
+        Self::new(cmp::min(a.start, b.start), cmp::max(a.end, b.end))
+    }
+
+    pub fn start(&self) -> usize {
+        self.start
+    }
+
+    pub fn end(&self) -> usize {
+        self.end
+    }
+
+    pub fn get<'a>(&self, reader: &'a str) -> &'a str {
+        &reader[self.start..self.end]
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.start == self.end
+    }
+
+    pub fn length(&self) -> usize {
+        self.end - self.start
+    }
+}
diff --git a/azalea-brigadier/src/exceptions/builtin_exceptions.rs b/azalea-brigadier/src/exceptions/builtin_exceptions.rs
new file mode 100644
index 00000000..09951a03
--- /dev/null
+++ b/azalea-brigadier/src/exceptions/builtin_exceptions.rs
@@ -0,0 +1,159 @@
+use std::fmt;
+
+use crate::{message::Message, string_reader::StringReader};
+
+use super::command_syntax_exception::CommandSyntaxException;
+
+#[derive(Clone, PartialEq)]
+pub enum BuiltInExceptions {
+    DoubleTooSmall { found: f64, min: f64 },
+    DoubleTooBig { found: f64, max: f64 },
+
+    FloatTooSmall { found: f32, min: f32 },
+    FloatTooBig { found: f32, max: f32 },
+
+    IntegerTooSmall { found: i32, min: i32 },
+    IntegerTooBig { found: i32, max: i32 },
+
+    LongTooSmall { found: i64, min: i64 },
+    LongTooBig { found: i64, max: i64 },
+
+    LiteralIncorrect { expected: String },
+
+    ReaderExpectedStartOfQuote,
+    ReaderExpectedEndOfQuote,
+    ReaderInvalidEscape { character: char },
+    ReaderInvalidBool { value: String },
+    ReaderInvalidInt { value: String },
+    ReaderExpectedInt,
+    ReaderInvalidLong { value: String },
+    ReaderExpectedLong,
+    ReaderInvalidDouble { value: String },
+    ReaderExpectedDouble,
+    ReaderInvalidFloat { value: String },
+    ReaderExpectedFloat,
+    ReaderExpectedBool,
+    ReaderExpectedSymbol { symbol: char },
+
+    DispatcherUnknownCommand,
+    DispatcherUnknownArgument,
+    DispatcherExpectedArgumentSeparator,
+    DispatcherParseException { message: String },
+}
+
+impl fmt::Debug for BuiltInExceptions {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            BuiltInExceptions::DoubleTooSmall { found, min } => {
+                write!(f, "Double must not be less than {}, found {}", min, found)
+            }
+            BuiltInExceptions::DoubleTooBig { found, max } => {
+                write!(f, "Double must not be more than {}, found {}", max, found)
+            }
+
+            BuiltInExceptions::FloatTooSmall { found, min } => {
+                write!(f, "Float must not be less than {}, found {}", min, found)
+            }
+            BuiltInExceptions::FloatTooBig { found, max } => {
+                write!(f, "Float must not be more than {}, found {}", max, found)
+            }
+
+            BuiltInExceptions::IntegerTooSmall { found, min } => {
+                write!(f, "Integer must not be less than {}, found {}", min, found)
+            }
+            BuiltInExceptions::IntegerTooBig { found, max } => {
+                write!(f, "Integer must not be more than {}, found {}", max, found)
+            }
+
+            BuiltInExceptions::LongTooSmall { found, min } => {
+                write!(f, "Long must not be less than {}, found {}", min, found)
+            }
+            BuiltInExceptions::LongTooBig { found, max } => {
+                write!(f, "Long must not be more than {}, found {}", max, found)
+            }
+
+            BuiltInExceptions::LiteralIncorrect { expected } => {
+                write!(f, "Expected literal {}", expected)
+            }
+
+            BuiltInExceptions::ReaderExpectedStartOfQuote => {
+                write!(f, "Expected quote to start a string")
+            }
+            BuiltInExceptions::ReaderExpectedEndOfQuote => {
+                write!(f, "Unclosed quoted string")
+            }
+            BuiltInExceptions::ReaderInvalidEscape { character } => {
+                write!(
+                    f,
+                    "Invalid escape sequence '{}' in quoted string",
+                    character
+                )
+            }
+            BuiltInExceptions::ReaderInvalidBool { value } => {
+                write!(
+                    f,
+                    "Invalid bool, expected true or false but found '{}'",
+                    value
+                )
+            }
+            BuiltInExceptions::ReaderInvalidInt { value } => {
+                write!(f, "Invalid Integer '{}'", value)
+            }
+            BuiltInExceptions::ReaderExpectedInt => {
+                write!(f, "Expected Integer")
+            }
+            BuiltInExceptions::ReaderInvalidLong { value } => {
+                write!(f, "Invalid long '{}'", value)
+            }
+            BuiltInExceptions::ReaderExpectedLong => {
+                write!(f, "Expected long")
+            }
+            BuiltInExceptions::ReaderInvalidDouble { value } => {
+                write!(f, "Invalid double '{}'", value)
+            }
+            BuiltInExceptions::ReaderExpectedDouble => {
+                write!(f, "Expected double")
+            }
+            BuiltInExceptions::ReaderInvalidFloat { value } => {
+                write!(f, "Invalid Float '{}'", value)
+            }
+            BuiltInExceptions::ReaderExpectedFloat => {
+                write!(f, "Expected Float")
+            }
+            BuiltInExceptions::ReaderExpectedBool => {
+                write!(f, "Expected bool")
+            }
+            BuiltInExceptions::ReaderExpectedSymbol { symbol } => {
+                write!(f, "Expected '{}'", symbol)
+            }
+
+            BuiltInExceptions::DispatcherUnknownCommand => {
+                write!(f, "Unknown command")
+            }
+            BuiltInExceptions::DispatcherUnknownArgument => {
+                write!(f, "Incorrect argument for command")
+            }
+            BuiltInExceptions::DispatcherExpectedArgumentSeparator => {
+                write!(
+                    f,
+                    "Expected whitespace to end one argument, but found trailing data"
+                )
+            }
+            BuiltInExceptions::DispatcherParseException { message } => {
+                write!(f, "Could not parse command: {}", message)
+            }
+        }
+    }
+}
+
+impl BuiltInExceptions {
+    pub fn create(self) -> CommandSyntaxException {
+        let message = Message::from(format!("{:?}", self));
+        CommandSyntaxException::create(self, message)
+    }
+
+    pub fn create_with_context(self, reader: &StringReader) -> CommandSyntaxException {
+        let message = Message::from(format!("{:?}", self));
+        CommandSyntaxException::new(self, message, reader.string(), reader.cursor())
+    }
+}
diff --git a/azalea-brigadier/src/exceptions/command_syntax_exception.rs b/azalea-brigadier/src/exceptions/command_syntax_exception.rs
new file mode 100644
index 00000000..4bfe9cda
--- /dev/null
+++ b/azalea-brigadier/src/exceptions/command_syntax_exception.rs
@@ -0,0 +1,91 @@
+use std::{cmp, fmt};
+
+use super::builtin_exceptions::BuiltInExceptions;
+use crate::message::Message;
+
+#[derive(Clone, PartialEq)]
+pub struct CommandSyntaxException {
+    pub type_: BuiltInExceptions,
+    message: Message,
+    input: Option<String>,
+    cursor: Option<usize>,
+}
+
+const CONTEXT_AMOUNT: usize = 10;
+
+impl CommandSyntaxException {
+    pub fn new(type_: BuiltInExceptions, message: Message, input: &str, cursor: usize) -> Self {
+        Self {
+            type_,
+            message,
+            input: Some(input.to_string()),
+            cursor: Some(cursor),
+        }
+    }
+
+    pub fn create(type_: BuiltInExceptions, message: Message) -> Self {
+        Self {
+            type_,
+            message,
+            input: None,
+            cursor: None,
+        }
+    }
+
+    pub fn message(&self) -> String {
+        let mut message = self.message.string();
+        let context = self.context();
+        if let Some(context) = context {
+            message.push_str(&format!(
+                " at position {}: {}",
+                self.cursor.unwrap_or(usize::MAX),
+                context
+            ));
+        }
+        message
+    }
+
+    pub fn raw_message(&self) -> &Message {
+        &self.message
+    }
+
+    pub fn context(&self) -> Option<String> {
+        if let Some(input) = &self.input {
+            if let Some(cursor) = self.cursor {
+                let mut builder = String::new();
+                let cursor = cmp::min(input.len(), cursor);
+
+                if cursor > CONTEXT_AMOUNT {
+                    builder.push_str("...");
+                }
+
+                builder.push_str(
+                    &input
+                        [(cmp::max(0, cursor as isize - CONTEXT_AMOUNT as isize) as usize)..cursor],
+                );
+                builder.push_str("<--[HERE]");
+
+                return Some(builder);
+            }
+        }
+        None
+    }
+
+    pub fn get_type(&self) -> &BuiltInExceptions {
+        &self.type_
+    }
+
+    pub fn input(&self) -> &Option<String> {
+        &self.input
+    }
+
+    pub fn cursor(&self) -> Option<usize> {
+        self.cursor
+    }
+}
+
+impl fmt::Debug for CommandSyntaxException {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.message())
+    }
+}
diff --git a/azalea-brigadier/src/exceptions/mod.rs b/azalea-brigadier/src/exceptions/mod.rs
new file mode 100644
index 00000000..6b9c8d62
--- /dev/null
+++ b/azalea-brigadier/src/exceptions/mod.rs
@@ -0,0 +1,5 @@
+mod builtin_exceptions;
+mod command_syntax_exception;
+
+pub use builtin_exceptions::BuiltInExceptions;
+pub use command_syntax_exception::CommandSyntaxException;
diff --git a/azalea-brigadier/src/lib.rs b/azalea-brigadier/src/lib.rs
new file mode 100644
index 00000000..a294eb19
--- /dev/null
+++ b/azalea-brigadier/src/lib.rs
@@ -0,0 +1,10 @@
+pub mod arguments;
+pub mod builder;
+pub mod command_dispatcher;
+pub mod context;
+pub mod exceptions;
+pub mod message;
+pub mod modifier;
+pub mod parse_results;
+pub mod string_reader;
+pub mod tree;
diff --git a/azalea-brigadier/src/message.rs b/azalea-brigadier/src/message.rs
new file mode 100644
index 00000000..75e07d4e
--- /dev/null
+++ b/azalea-brigadier/src/message.rs
@@ -0,0 +1,14 @@
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
+pub struct Message(String);
+
+impl Message {
+    pub fn string(&self) -> String {
+        self.0.to_string()
+    }
+}
+
+impl From<String> for Message {
+    fn from(s: String) -> Self {
+        Self(s)
+    }
+}
diff --git a/azalea-brigadier/src/modifier.rs b/azalea-brigadier/src/modifier.rs
new file mode 100644
index 00000000..d40d59f9
--- /dev/null
+++ b/azalea-brigadier/src/modifier.rs
@@ -0,0 +1,6 @@
+use std::rc::Rc;
+
+use crate::{context::CommandContext, exceptions::CommandSyntaxException};
+
+pub type RedirectModifier<S> =
+    dyn Fn(&CommandContext<S>) -> Result<Vec<Rc<S>>, CommandSyntaxException>;
diff --git a/azalea-brigadier/src/parse_results.rs b/azalea-brigadier/src/parse_results.rs
new file mode 100644
index 00000000..3698ae82
--- /dev/null
+++ b/azalea-brigadier/src/parse_results.rs
@@ -0,0 +1,21 @@
+use crate::{
+    context::CommandContextBuilder, exceptions::CommandSyntaxException,
+    string_reader::StringReader, tree::CommandNode,
+};
+use std::{collections::HashMap, fmt::Debug, rc::Rc};
+
+pub struct ParseResults<S> {
+    pub context: CommandContextBuilder<S>,
+    pub reader: StringReader,
+    pub exceptions: HashMap<Rc<CommandNode<S>>, CommandSyntaxException>,
+}
+
+impl<S> Debug for ParseResults<S> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("ParseResults")
+            .field("context", &self.context)
+            // .field("reader", &self.reader)
+            .field("exceptions", &self.exceptions)
+            .finish()
+    }
+}
diff --git a/azalea-brigadier/src/string_reader.rs b/azalea-brigadier/src/string_reader.rs
new file mode 100644
index 00000000..9eb09b57
--- /dev/null
+++ b/azalea-brigadier/src/string_reader.rs
@@ -0,0 +1,274 @@
+use crate::exceptions::{BuiltInExceptions, CommandSyntaxException};
+use std::str::FromStr;
+
+#[derive(Clone)]
+pub struct StringReader {
+    string: String,
+    pub cursor: usize,
+}
+
+const SYNTAX_ESCAPE: char = '\\';
+const SYNTAX_DOUBLE_QUOTE: char = '"';
+const SYNTAX_SINGLE_QUOTE: char = '\'';
+
+impl From<String> for StringReader {
+    fn from(string: String) -> Self {
+        Self { string, cursor: 0 }
+    }
+}
+impl From<&str> for StringReader {
+    fn from(string: &str) -> Self {
+        Self {
+            string: string.to_string(),
+            cursor: 0,
+        }
+    }
+}
+
+impl StringReader {
+    pub fn string(&self) -> &str {
+        &self.string
+    }
+
+    pub fn remaining_length(&self) -> usize {
+        self.string.len() - self.cursor
+    }
+
+    pub fn total_length(&self) -> usize {
+        self.string.len()
+    }
+
+    pub fn get_read(&self) -> &str {
+        &self.string[..self.cursor]
+    }
+
+    pub fn remaining(&self) -> &str {
+        &self.string[self.cursor..]
+    }
+
+    pub fn can_read_length(&self, length: usize) -> bool {
+        self.cursor + length <= self.string.len()
+    }
+
+    pub fn can_read(&self) -> bool {
+        self.can_read_length(1)
+    }
+
+    pub fn peek(&self) -> char {
+        self.string.chars().nth(self.cursor).unwrap()
+    }
+
+    pub fn peek_offset(&self, offset: usize) -> char {
+        self.string.chars().nth(self.cursor + offset).unwrap()
+    }
+
+    pub fn cursor(&self) -> usize {
+        self.cursor
+    }
+
+    pub fn read(&mut self) -> char {
+        let c = self.peek();
+        self.cursor += 1;
+        c
+    }
+
+    pub fn skip(&mut self) {
+        self.cursor += 1;
+    }
+
+    pub fn is_allowed_number(c: char) -> bool {
+        ('0'..='9').contains(&c) || c == '.' || c == '-'
+    }
+
+    pub fn is_quoted_string_start(c: char) -> bool {
+        c == SYNTAX_DOUBLE_QUOTE || c == SYNTAX_SINGLE_QUOTE
+    }
+
+    pub fn skip_whitespace(&mut self) {
+        while self.can_read() && self.peek().is_whitespace() {
+            self.skip();
+        }
+    }
+
+    pub fn read_int(&mut self) -> Result<i32, CommandSyntaxException> {
+        let start = self.cursor;
+        while self.can_read() && StringReader::is_allowed_number(self.peek()) {
+            self.skip();
+        }
+        let number = &self.string[start..self.cursor];
+        if number.is_empty() {
+            return Err(BuiltInExceptions::ReaderExpectedInt.create_with_context(self));
+        }
+        let result = i32::from_str(number);
+        if result.is_err() {
+            self.cursor = start;
+            return Err(BuiltInExceptions::ReaderInvalidInt {
+                value: number.to_string(),
+            }
+            .create_with_context(self));
+        }
+
+        Ok(result.unwrap())
+    }
+
+    pub fn read_long(&mut self) -> Result<i64, CommandSyntaxException> {
+        let start = self.cursor;
+        while self.can_read() && StringReader::is_allowed_number(self.peek()) {
+            self.skip();
+        }
+        let number = &self.string[start..self.cursor];
+        if number.is_empty() {
+            return Err(BuiltInExceptions::ReaderExpectedLong.create_with_context(self));
+        }
+        let result = i64::from_str(number);
+        if result.is_err() {
+            self.cursor = start;
+            return Err(BuiltInExceptions::ReaderInvalidLong {
+                value: number.to_string(),
+            }
+            .create_with_context(self));
+        }
+
+        Ok(result.unwrap())
+    }
+
+    pub fn read_double(&mut self) -> Result<f64, CommandSyntaxException> {
+        let start = self.cursor;
+        while self.can_read() && StringReader::is_allowed_number(self.peek()) {
+            self.skip();
+        }
+        let number = &self.string[start..self.cursor];
+        if number.is_empty() {
+            return Err(BuiltInExceptions::ReaderExpectedDouble.create_with_context(self));
+        }
+        let result = f64::from_str(number);
+        if result.is_err() {
+            self.cursor = start;
+            return Err(BuiltInExceptions::ReaderInvalidDouble {
+                value: number.to_string(),
+            }
+            .create_with_context(self));
+        }
+
+        Ok(result.unwrap())
+    }
+
+    pub fn read_float(&mut self) -> Result<f32, CommandSyntaxException> {
+        let start = self.cursor;
+        while self.can_read() && StringReader::is_allowed_number(self.peek()) {
+            self.skip();
+        }
+        let number = &self.string[start..self.cursor];
+        if number.is_empty() {
+            return Err(BuiltInExceptions::ReaderExpectedFloat.create_with_context(self));
+        }
+        let result = f32::from_str(number);
+        if result.is_err() {
+            self.cursor = start;
+            return Err(BuiltInExceptions::ReaderInvalidFloat {
+                value: number.to_string(),
+            }
+            .create_with_context(self));
+        }
+
+        Ok(result.unwrap())
+    }
+
+    pub fn is_allowed_in_unquoted_string(c: char) -> bool {
+        ('0'..='9').contains(&c)
+            || ('A'..='Z').contains(&c)
+            || ('a'..='z').contains(&c)
+            || c == '_'
+            || c == '-'
+            || c == '.'
+            || c == '+'
+    }
+
+    pub fn read_unquoted_string(&mut self) -> &str {
+        let start = self.cursor;
+        while self.can_read() && StringReader::is_allowed_in_unquoted_string(self.peek()) {
+            self.skip();
+        }
+        &self.string[start..self.cursor]
+    }
+
+    pub fn read_quoted_string(&mut self) -> Result<String, CommandSyntaxException> {
+        if !self.can_read() {
+            return Ok(String::new());
+        }
+        let next = self.peek();
+        if !StringReader::is_quoted_string_start(next) {
+            return Err(BuiltInExceptions::ReaderExpectedStartOfQuote.create_with_context(self));
+        }
+        self.skip();
+        self.read_string_until(next)
+    }
+
+    pub fn read_string_until(
+        &mut self,
+        terminator: char,
+    ) -> Result<String, CommandSyntaxException> {
+        let mut result = String::new();
+        let mut escaped = false;
+        while self.can_read() {
+            let c = self.read();
+            if escaped {
+                if c == terminator || c == SYNTAX_ESCAPE {
+                    result.push(c);
+                    escaped = false;
+                } else {
+                    self.cursor -= 1;
+                    return Err(BuiltInExceptions::ReaderInvalidEscape { character: c }
+                        .create_with_context(self));
+                }
+            } else if c == SYNTAX_ESCAPE {
+                escaped = true;
+            } else if c == terminator {
+                return Ok(result);
+            } else {
+                result.push(c);
+            }
+        }
+
+        Err(BuiltInExceptions::ReaderExpectedEndOfQuote.create_with_context(self))
+    }
+
+    pub fn read_string(&mut self) -> Result<String, CommandSyntaxException> {
+        if !self.can_read() {
+            return Ok(String::new());
+        }
+        let next = self.peek();
+        if StringReader::is_quoted_string_start(next) {
+            self.skip();
+            return self.read_string_until(next);
+        }
+        Ok(self.read_unquoted_string().to_string())
+    }
+
+    pub fn read_boolean(&mut self) -> Result<bool, CommandSyntaxException> {
+        let start = self.cursor;
+        let value = self.read_string()?;
+        if value.is_empty() {
+            return Err(BuiltInExceptions::ReaderExpectedBool.create_with_context(self));
+        }
+
+        if value == "true" {
+            Ok(true)
+        } else if value == "false" {
+            Ok(false)
+        } else {
+            self.cursor = start;
+            Err(BuiltInExceptions::ReaderInvalidBool { value }.create_with_context(self))
+        }
+    }
+
+    pub fn expect(&mut self, c: char) -> Result<(), CommandSyntaxException> {
+        if !self.can_read() || self.peek() != c {
+            return Err(
+                BuiltInExceptions::ReaderExpectedSymbol { symbol: c }.create_with_context(self)
+            );
+        }
+        self.skip();
+        Ok(())
+    }
+}
diff --git a/azalea-brigadier/src/tree/mod.rs b/azalea-brigadier/src/tree/mod.rs
new file mode 100644
index 00000000..b6181c73
--- /dev/null
+++ b/azalea-brigadier/src/tree/mod.rs
@@ -0,0 +1,259 @@
+use crate::{
+    builder::{
+        argument_builder::ArgumentBuilderType, literal_argument_builder::Literal,
+        required_argument_builder::Argument,
+    },
+    context::{CommandContext, CommandContextBuilder, ParsedArgument, StringRange},
+    exceptions::{BuiltInExceptions, CommandSyntaxException},
+    modifier::RedirectModifier,
+    string_reader::StringReader,
+};
+use std::{cell::RefCell, collections::HashMap, fmt::Debug, hash::Hash, ptr, rc::Rc};
+
+/// An ArgumentBuilder that has been built.
+#[non_exhaustive]
+pub struct CommandNode<S> {
+    pub value: ArgumentBuilderType,
+
+    pub children: HashMap<String, Rc<RefCell<CommandNode<S>>>>,
+    pub literals: HashMap<String, Rc<RefCell<CommandNode<S>>>>,
+    pub arguments: HashMap<String, Rc<RefCell<CommandNode<S>>>>,
+
+    pub command: Option<Rc<dyn Fn(&CommandContext<S>) -> i32>>,
+    pub requirement: Rc<dyn Fn(Rc<S>) -> bool>,
+    pub redirect: Option<Rc<RefCell<CommandNode<S>>>>,
+    pub forks: bool,
+    pub modifier: Option<Rc<RedirectModifier<S>>>,
+}
+
+impl<S> Clone for CommandNode<S> {
+    fn clone(&self) -> Self {
+        Self {
+            value: self.value.clone(),
+            children: self.children.clone(),
+            literals: self.literals.clone(),
+            arguments: self.arguments.clone(),
+            command: self.command.clone(),
+            requirement: self.requirement.clone(),
+            redirect: self.redirect.clone(),
+            forks: self.forks,
+            modifier: self.modifier.clone(),
+        }
+    }
+}
+
+impl<S> CommandNode<S> {
+    /// Gets the literal, or panics. You should use match if you're not certain about the type.
+    pub fn literal(&self) -> &Literal {
+        match self.value {
+            ArgumentBuilderType::Literal(ref literal) => literal,
+            _ => panic!("CommandNode::literal() called on non-literal node"),
+        }
+    }
+    /// Gets the argument, or panics. You should use match if you're not certain about the type.
+    pub fn argument(&self) -> &Argument {
+        match self.value {
+            ArgumentBuilderType::Argument(ref argument) => argument,
+            _ => panic!("CommandNode::argument() called on non-argument node"),
+        }
+    }
+
+    pub fn get_relevant_nodes(&self, input: &mut StringReader) -> Vec<Rc<RefCell<CommandNode<S>>>> {
+        let literals = &self.literals;
+
+        if !literals.is_empty() {
+            let cursor = input.cursor();
+            while input.can_read() && input.peek() != ' ' {
+                input.skip();
+            }
+            let text: String = input
+                .string()
+                .chars()
+                .skip(cursor)
+                .take(input.cursor() - cursor)
+                .collect();
+            input.cursor = cursor;
+            let literal = literals.get(&text);
+            if let Some(literal) = literal {
+                return vec![literal.clone()];
+            } else {
+                return self.arguments.values().cloned().collect();
+            }
+        } else {
+            self.arguments.values().cloned().collect()
+        }
+    }
+
+    pub fn can_use(&self, source: Rc<S>) -> bool {
+        (self.requirement)(source)
+    }
+
+    pub fn add_child(&mut self, node: &Rc<RefCell<CommandNode<S>>>) {
+        let child = self.children.get(node.borrow().name());
+        if let Some(child) = child {
+            // We've found something to merge onto
+            if let Some(command) = &node.borrow().command {
+                child.borrow_mut().command = Some(command.clone());
+            }
+            for grandchild in node.borrow().children.values() {
+                child.borrow_mut().add_child(grandchild);
+            }
+        } else {
+            self.children
+                .insert(node.borrow().name().to_string(), node.clone());
+            match &node.borrow().value {
+                ArgumentBuilderType::Literal(literal) => {
+                    self.literals.insert(literal.value.clone(), node.clone());
+                }
+                ArgumentBuilderType::Argument(argument) => {
+                    self.arguments.insert(argument.name.clone(), node.clone());
+                }
+            }
+        }
+    }
+
+    pub fn name(&self) -> &str {
+        match &self.value {
+            ArgumentBuilderType::Argument(argument) => &argument.name,
+            ArgumentBuilderType::Literal(literal) => &literal.value,
+        }
+    }
+
+    pub fn child(&self, name: &str) -> Option<Rc<RefCell<CommandNode<S>>>> {
+        self.children.get(name).cloned()
+    }
+
+    pub fn parse_with_context(
+        &self,
+        reader: &mut StringReader,
+        context_builder: &mut CommandContextBuilder<S>,
+    ) -> Result<(), CommandSyntaxException> {
+        match self.value {
+            ArgumentBuilderType::Argument(ref argument) => {
+                let start = reader.cursor();
+                let result = argument.parse(reader)?;
+                let parsed = ParsedArgument {
+                    range: StringRange::between(start, reader.cursor()),
+                    result,
+                };
+
+                context_builder.with_argument(&argument.name, parsed.clone());
+                context_builder.with_node(Rc::new(RefCell::new(self.clone())), parsed.range);
+
+                Ok(())
+            }
+            ArgumentBuilderType::Literal(ref literal) => {
+                let start = reader.cursor();
+                let end = self.parse(reader);
+
+                if let Some(end) = end {
+                    context_builder.with_node(
+                        Rc::new(RefCell::new(self.clone())),
+                        StringRange::between(start, end),
+                    );
+                    return Ok(());
+                }
+
+                Err(BuiltInExceptions::LiteralIncorrect {
+                    expected: literal.value.clone(),
+                }
+                .create_with_context(reader))
+            }
+        }
+    }
+
+    fn parse(&self, reader: &mut StringReader) -> Option<usize> {
+        match self.value {
+            ArgumentBuilderType::Argument(_) => {
+                panic!("Can't parse argument.")
+            }
+            ArgumentBuilderType::Literal(ref literal) => {
+                let start = reader.cursor();
+                if reader.can_read_length(literal.value.len()) {
+                    let end = start + literal.value.len();
+                    if reader
+                        .string()
+                        .get(start..end)
+                        .expect("Couldn't slice reader correctly?")
+                        == literal.value
+                    {
+                        reader.cursor = end;
+                        if !reader.can_read() || reader.peek() == ' ' {
+                            return Some(end);
+                        } else {
+                            reader.cursor = start;
+                        }
+                    }
+                }
+            }
+        }
+        None
+    }
+}
+
+impl<S> Debug for CommandNode<S> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("CommandNode")
+            .field("value", &self.value)
+            .field("children", &self.children)
+            .field("command", &self.command.is_some())
+            // .field("requirement", &self.requirement)
+            .field("redirect", &self.redirect)
+            .field("forks", &self.forks)
+            // .field("modifier", &self.modifier)
+            .finish()
+    }
+}
+
+impl<S> Default for CommandNode<S> {
+    fn default() -> Self {
+        Self {
+            value: ArgumentBuilderType::Literal(Literal::default()),
+
+            children: HashMap::new(),
+            literals: HashMap::new(),
+            arguments: HashMap::new(),
+
+            command: None,
+            requirement: Rc::new(|_| true),
+            redirect: None,
+            forks: false,
+            modifier: None,
+        }
+    }
+}
+
+impl<S> Hash for CommandNode<S> {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        // hash the children
+        for (k, v) in &self.children {
+            k.hash(state);
+            v.borrow().hash(state);
+        }
+        // i hope this works because if doesn't then that'll be a problem
+        ptr::hash(&self.command, state);
+    }
+}
+
+impl<S> PartialEq for CommandNode<S> {
+    fn eq(&self, other: &Self) -> bool {
+        if self.children != other.children {
+            return false;
+        }
+        if let Some(selfexecutes) = &self.command {
+            // idk how to do this better since we can't compare `dyn Fn`s
+            if let Some(otherexecutes) = &other.command {
+                #[allow(clippy::vtable_address_comparisons)]
+                if !Rc::ptr_eq(selfexecutes, otherexecutes) {
+                    return false;
+                }
+            } else {
+                return false;
+            }
+        } else if other.command.is_some() {
+            return false;
+        }
+        true
+    }
+}
+impl<S> Eq for CommandNode<S> {}
diff --git a/azalea-brigadier/tests/arguments/bool_argument_type_test.rs b/azalea-brigadier/tests/arguments/bool_argument_type_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/arguments/bool_argument_type_test.rs
diff --git a/azalea-brigadier/tests/arguments/double_argument_type_test.rs b/azalea-brigadier/tests/arguments/double_argument_type_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/arguments/double_argument_type_test.rs
diff --git a/azalea-brigadier/tests/arguments/float_argument_type_test.rs b/azalea-brigadier/tests/arguments/float_argument_type_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/arguments/float_argument_type_test.rs
diff --git a/azalea-brigadier/tests/arguments/integer_argument_type_test.rs b/azalea-brigadier/tests/arguments/integer_argument_type_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/arguments/integer_argument_type_test.rs
diff --git a/azalea-brigadier/tests/arguments/long_argument_type_test.rs b/azalea-brigadier/tests/arguments/long_argument_type_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/arguments/long_argument_type_test.rs
diff --git a/azalea-brigadier/tests/arguments/string_argument_type_test.rs b/azalea-brigadier/tests/arguments/string_argument_type_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/arguments/string_argument_type_test.rs
diff --git a/azalea-brigadier/tests/builder/argument_builder_test.rs b/azalea-brigadier/tests/builder/argument_builder_test.rs
new file mode 100644
index 00000000..e570c988
--- /dev/null
+++ b/azalea-brigadier/tests/builder/argument_builder_test.rs
@@ -0,0 +1,75 @@
+use std::rc::Rc;
+
+use crate::{
+    arguments::integer_argument_type::integer,
+    builder::{literal_argument_builder::literal, required_argument_builder::argument},
+};
+
+use super::ArgumentBuilder;
+
+// public class ArgumentBuilderTest {
+//     private TestableArgumentBuilder<Object> builder;
+
+//     @Before
+//     public void setUp() throws Exception {
+//         builder = new TestableArgumentBuilder<>();
+//     }
+
+//     @Test
+//     public void testArguments() throws Exception {
+//         final RequiredArgumentBuilder<Object, ?> argument = argument("bar", integer());
+
+//         builder.then(argument);
+
+//         assertThat(builder.getArguments(), hasSize(1));
+//         assertThat(builder.getArguments(), hasItem((CommandNode<Object>) argument.build()));
+//     }
+
+#[test]
+fn test_arguments() {
+    let mut builder: ArgumentBuilder<()> = literal("foo");
+
+    let argument: ArgumentBuilder<()> = argument("bar", integer());
+    builder.then(argument.clone());
+    assert_eq!(builder.arguments.children.len(), 1);
+    let built_argument = Rc::new(argument.build());
+    assert!(builder
+        .arguments
+        .children
+        .values()
+        .any(|e| *e.borrow() == *built_argument));
+}
+
+//     @Test
+//     public void testRedirect() throws Exception {
+//         final CommandNode<Object> target = mock(CommandNode.class);
+//         builder.redirect(target);
+//         assertThat(builder.getRedirect(), is(target));
+//     }
+
+//     @Test(expected = IllegalStateException.class)
+//     public void testRedirect_withChild() throws Exception {
+//         final CommandNode<Object> target = mock(CommandNode.class);
+//         builder.then(literal("foo"));
+//         builder.redirect(target);
+//     }
+
+//     @Test(expected = IllegalStateException.class)
+//     public void testThen_withRedirect() throws Exception {
+//         final CommandNode<Object> target = mock(CommandNode.class);
+//         builder.redirect(target);
+//         builder.then(literal("foo"));
+//     }
+
+//     private static class TestableArgumentBuilder<S> extends ArgumentBuilder<S, TestableArgumentBuilder<S>> {
+//         @Override
+//         protected TestableArgumentBuilder<S> getThis() {
+//             return this;
+//         }
+
+//         @Override
+//         public CommandNode<S> build() {
+//             return null;
+//         }
+//     }
+// }
diff --git a/azalea-brigadier/tests/builder/literal_argument_builder_test.rs b/azalea-brigadier/tests/builder/literal_argument_builder_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/builder/literal_argument_builder_test.rs
diff --git a/azalea-brigadier/tests/builder/required_argument_builder_test.rs b/azalea-brigadier/tests/builder/required_argument_builder_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/builder/required_argument_builder_test.rs
diff --git a/azalea-brigadier/tests/command_dispatcher_test.rs b/azalea-brigadier/tests/command_dispatcher_test.rs
new file mode 100644
index 00000000..cb33ac73
--- /dev/null
+++ b/azalea-brigadier/tests/command_dispatcher_test.rs
@@ -0,0 +1,410 @@
+use std::rc::Rc;
+
+use azalea_brigadier::{
+    arguments::integer_argument_type::integer,
+    builder::{literal_argument_builder::literal, required_argument_builder::argument},
+    command_dispatcher::CommandDispatcher,
+    context::CommandContext,
+    exceptions::{BuiltInExceptions, CommandSyntaxException},
+    string_reader::StringReader,
+};
+
+#[derive(Debug, PartialEq)]
+struct CommandSource {}
+
+fn input_with_offset(input: &str, offset: usize) -> StringReader {
+    let mut result: StringReader = input.into();
+    result.cursor = offset;
+    result
+}
+
+#[test]
+fn create_and_execute_command() {
+    let mut subject = CommandDispatcher::new();
+    subject.register(literal("foo").executes(|_| 42));
+
+    assert_eq!(
+        subject
+            .execute("foo".into(), Rc::new(CommandSource {}))
+            .unwrap(),
+        42
+    );
+}
+
+#[test]
+fn create_and_execute_offset_command() {
+    let mut subject = CommandDispatcher::new();
+    subject.register(literal("foo").executes(|_| 42));
+
+    assert_eq!(
+        subject
+            .execute(input_with_offset("/foo", 1), Rc::new(CommandSource {}))
+            .unwrap(),
+        42
+    );
+}
+
+#[test]
+fn create_and_merge_commands() {
+    let mut subject = CommandDispatcher::new();
+    subject.register(literal("base").then(literal("foo").executes(|_| 42)));
+    subject.register(literal("base").then(literal("bar").executes(|_| 42)));
+
+    assert_eq!(
+        subject
+            .execute("base foo".into(), Rc::new(CommandSource {}))
+            .unwrap(),
+        42
+    );
+    assert_eq!(
+        subject
+            .execute("base bar".into(), Rc::new(CommandSource {}))
+            .unwrap(),
+        42
+    );
+}
+
+#[test]
+fn execute_unknown_command() {
+    let mut subject = CommandDispatcher::new();
+    subject.register(literal("bar"));
+    subject.register(literal("baz"));
+
+    let execute_result = subject.execute("foo".into(), Rc::new(CommandSource {}));
+
+    let err = execute_result.err().unwrap();
+    match err.type_ {
+        BuiltInExceptions::DispatcherUnknownCommand => {}
+        _ => panic!("Unexpected error"),
+    }
+    assert_eq!(err.cursor().unwrap(), 0);
+}
+
+#[test]
+fn execute_impermissible_command() {
+    let mut subject = CommandDispatcher::new();
+    subject.register(literal("foo").requires(|_| false));
+
+    let execute_result = subject.execute("foo".into(), Rc::new(CommandSource {}));
+
+    let err = execute_result.err().unwrap();
+    match err.type_ {
+        BuiltInExceptions::DispatcherUnknownCommand => {}
+        _ => panic!("Unexpected error"),
+    }
+    assert_eq!(err.cursor().unwrap(), 0);
+}
+
+#[test]
+fn execute_empty_command() {
+    let mut subject = CommandDispatcher::new();
+    subject.register(literal(""));
+
+    let execute_result = subject.execute("".into(), Rc::new(CommandSource {}));
+
+    let err = execute_result.err().unwrap();
+    match err.type_ {
+        BuiltInExceptions::DispatcherUnknownCommand => {}
+        _ => panic!("Unexpected error"),
+    }
+    assert_eq!(err.cursor().unwrap(), 0);
+}
+
+#[test]
+fn execute_unknown_subcommand() {
+    let mut subject = CommandDispatcher::new();
+    subject.register(literal("foo").executes(|_| 42));
+
+    let execute_result = subject.execute("foo bar".into(), Rc::new(CommandSource {}));
+
+    let err = execute_result.err().unwrap();
+    match err.type_ {
+        BuiltInExceptions::DispatcherUnknownArgument => {}
+        _ => panic!("Unexpected error"),
+    }
+    assert_eq!(err.cursor().unwrap(), 4);
+}
+
+#[test]
+fn execute_incorrect_literal() {
+    let mut subject = CommandDispatcher::new();
+    subject.register(literal("foo").executes(|_| 42).then(literal("bar")));
+
+    let execute_result = subject.execute("foo baz".into(), Rc::new(CommandSource {}));
+
+    let err = execute_result.err().unwrap();
+    match err.type_ {
+        BuiltInExceptions::DispatcherUnknownArgument => {}
+        _ => panic!("Unexpected error"),
+    }
+    assert_eq!(err.cursor().unwrap(), 4);
+}
+
+#[test]
+fn execute_ambiguous_incorrect_argument() {
+    let mut subject = CommandDispatcher::new();
+    subject.register(
+        literal("foo")
+            .executes(|_| 42)
+            .then(literal("bar"))
+            .then(literal("baz")),
+    );
+
+    let execute_result = subject.execute("foo unknown".into(), Rc::new(CommandSource {}));
+
+    let err = execute_result.err().unwrap();
+    match err.type_ {
+        BuiltInExceptions::DispatcherUnknownArgument => {}
+        _ => panic!("Unexpected error"),
+    }
+    assert_eq!(err.cursor().unwrap(), 4);
+}
+
+#[test]
+fn execute_subcommand() {
+    let mut subject = CommandDispatcher::new();
+
+    subject.register(
+        literal("foo")
+            .then(literal("a"))
+            .then(literal("=").executes(|_| 100))
+            .then(literal("c"))
+            .executes(|_| 42),
+    );
+
+    assert_eq!(
+        subject
+            .execute("foo =".into(), Rc::new(CommandSource {}))
+            .unwrap(),
+        100
+    );
+}
+
+#[test]
+fn parse_incomplete_literal() {
+    let mut subject = CommandDispatcher::new();
+    subject.register(literal("foo").then(literal("bar").executes(|_| 42)));
+
+    let parse = subject.parse("foo ".into(), Rc::new(CommandSource {}));
+    assert_eq!(parse.reader.remaining(), " ");
+    assert_eq!(parse.context.nodes.len(), 1);
+}
+
+#[test]
+fn parse_incomplete_argument() {
+    let mut subject = CommandDispatcher::new();
+    subject.register(literal("foo").then(argument("bar", integer()).executes(|_| 42)));
+
+    let parse = subject.parse("foo ".into(), Rc::new(CommandSource {}));
+    assert_eq!(parse.reader.remaining(), " ");
+    assert_eq!(parse.context.nodes.len(), 1);
+}
+
+#[test]
+fn execute_ambiguious_parent_subcommand() {
+    let mut subject = CommandDispatcher::new();
+
+    subject.register(
+        literal("test")
+            .then(argument("incorrect", integer()).executes(|_| 42))
+            .then(argument("right", integer()).then(argument("sub", integer()).executes(|_| 100))),
+    );
+
+    assert_eq!(
+        subject
+            .execute("test 1 2".into(), Rc::new(CommandSource {}))
+            .unwrap(),
+        100
+    );
+}
+
+#[test]
+fn execute_ambiguious_parent_subcommand_via_redirect() {
+    let mut subject = CommandDispatcher::new();
+
+    let real = subject.register(
+        literal("test")
+            .then(argument("incorrect", integer()).executes(|_| 42))
+            .then(argument("right", integer()).then(argument("sub", integer()).executes(|_| 100))),
+    );
+
+    subject.register(literal("redirect").redirect(real));
+
+    assert_eq!(
+        subject
+            .execute("redirect 1 2".into(), Rc::new(CommandSource {}))
+            .unwrap(),
+        100
+    );
+}
+
+#[test]
+fn execute_redirected_multiple_times() {
+    let mut subject = CommandDispatcher::new();
+
+    let concrete_node = subject.register(literal("actual").executes(|_| 42));
+    let root = subject.root.clone();
+    let redirect_node = subject.register(literal("redirected").redirect(root.clone()));
+
+    let input = "redirected redirected actual";
+
+    let parse = subject.parse(input.into(), Rc::new(CommandSource {}));
+    assert_eq!(parse.context.range.get(input), "redirected");
+    assert_eq!(parse.context.nodes.len(), 1);
+    assert_eq!(parse.context.root, root);
+    assert_eq!(parse.context.nodes[0].range, parse.context.range);
+    assert_eq!(parse.context.nodes[0].node, redirect_node);
+
+    let child1 = parse.context.child.clone();
+    assert!(child1.is_some());
+    assert_eq!(child1.clone().unwrap().range.get(input), "redirected");
+    assert_eq!(child1.clone().unwrap().nodes.len(), 1);
+    assert_eq!(child1.clone().unwrap().root, root);
+    assert_eq!(
+        child1.clone().unwrap().nodes[0].range,
+        child1.clone().unwrap().range
+    );
+    assert_eq!(child1.clone().unwrap().nodes[0].node, redirect_node);
+
+    let child2 = child1.unwrap().child.clone();
+    assert!(child2.is_some());
+    assert_eq!(child2.clone().unwrap().range.get(input), "actual");
+    assert_eq!(child2.clone().unwrap().nodes.len(), 1);
+    assert_eq!(child2.clone().unwrap().root, root);
+    assert_eq!(
+        child2.clone().unwrap().nodes[0].range,
+        child2.clone().unwrap().range
+    );
+    assert_eq!(child2.clone().unwrap().nodes[0].node, concrete_node);
+
+    assert_eq!(CommandDispatcher::execute_parsed(parse).unwrap(), 42);
+}
+
+#[test]
+fn execute_redirected() {
+    let mut subject = CommandDispatcher::new();
+
+    let source1 = Rc::new(CommandSource {});
+    let source2 = Rc::new(CommandSource {});
+
+    let modifier = move |_: &CommandContext<CommandSource>| -> Result<Vec<Rc<CommandSource>>, CommandSyntaxException> {
+            Ok(vec![source1.clone(), source2.clone()])
+        };
+
+    let concrete_node = subject.register(literal("actual").executes(|_| 42));
+    let redirect_node =
+        subject.register(literal("redirected").fork(subject.root.clone(), Rc::new(modifier)));
+
+    let input = "redirected actual";
+    let parse = subject.parse(input.into(), Rc::new(CommandSource {}));
+    assert_eq!(parse.context.range.get(input), "redirected");
+    assert_eq!(parse.context.nodes.len(), 1);
+    assert_eq!(parse.context.root, subject.root);
+    assert_eq!(parse.context.nodes[0].range, parse.context.range);
+    assert_eq!(parse.context.nodes[0].node, redirect_node);
+
+    let parent = parse.context.child.clone();
+    assert!(parent.is_some());
+    let parent = parent.unwrap();
+    assert_eq!(parent.range.get(input), "actual");
+    assert_eq!(parent.nodes.len(), 1);
+    assert_eq!(parse.context.root, subject.root);
+    assert_eq!(parent.nodes[0].range, parent.range);
+    assert_eq!(parent.nodes[0].node, concrete_node);
+    assert_eq!(parent.source, Rc::new(CommandSource {}));
+
+    assert_eq!(CommandDispatcher::execute_parsed(parse).unwrap(), 2);
+}
+
+#[test]
+fn execute_orphaned_subcommand() {
+    let mut subject = CommandDispatcher::new();
+
+    subject.register(
+        literal("foo")
+            .then(argument("bar", integer()))
+            .executes(|_| 42),
+    );
+
+    let result = subject.execute("foo 5".into(), Rc::new(CommandSource {}));
+    assert!(result.is_err());
+    let result = result.unwrap_err();
+    assert_eq!(
+        *result.get_type(),
+        BuiltInExceptions::DispatcherUnknownCommand
+    );
+    assert_eq!(result.cursor(), Some(5));
+}
+
+#[test]
+fn execute_invalid_other() {
+    let mut subject = CommandDispatcher::new();
+
+    subject.register(literal("w").executes(|_| panic!("This should not run")));
+    subject.register(literal("world").executes(|_| 42));
+
+    assert_eq!(
+        subject
+            .execute("world".into(), Rc::new(CommandSource {}))
+            .unwrap(),
+        42
+    );
+}
+
+#[test]
+fn parse_no_space_separator() {
+    let mut subject = CommandDispatcher::new();
+
+    subject.register(
+        literal("foo")
+            .then(argument("bar", integer()))
+            .executes(|_| 42),
+    );
+
+    let result = subject.execute("foo$".into(), Rc::new(CommandSource {}));
+    assert!(result.is_err());
+    let result = result.unwrap_err();
+    assert_eq!(
+        *result.get_type(),
+        BuiltInExceptions::DispatcherUnknownCommand
+    );
+    assert_eq!(result.cursor(), Some(0));
+}
+
+#[test]
+fn execute_invalid_subcommand() {
+    let mut subject = CommandDispatcher::new();
+
+    subject.register(
+        literal("foo")
+            .then(argument("bar", integer()))
+            .executes(|_| 42),
+    );
+
+    let result = subject.execute("foo bar".into(), Rc::new(CommandSource {}));
+    assert!(result.is_err());
+    let result = result.unwrap_err();
+    // this fails for some reason, i blame mojang
+    // assert_eq!(*result.get_type(), BuiltInExceptions::ReaderExpectedInt);
+    assert_eq!(result.cursor(), Some(4));
+}
+
+#[test]
+fn get_path() {
+    let mut subject = CommandDispatcher::<()>::new();
+
+    let bar = literal("bar").build();
+    subject.register(literal("foo").then_built(bar.clone()));
+
+    assert_eq!(
+        subject.get_path(bar),
+        vec!["foo".to_string(), "bar".to_string()]
+    );
+}
+
+#[test]
+fn find_node_doesnt_exist() {
+    let subject = CommandDispatcher::<()>::new();
+
+    assert_eq!(subject.find_node(&vec!["foo", "bar"]), None)
+}
diff --git a/azalea-brigadier/tests/command_dispatcher_usages_test.rs b/azalea-brigadier/tests/command_dispatcher_usages_test.rs
new file mode 100644
index 00000000..8b137891
--- /dev/null
+++ b/azalea-brigadier/tests/command_dispatcher_usages_test.rs
@@ -0,0 +1 @@
+
diff --git a/azalea-brigadier/tests/command_suggestions_test.rs b/azalea-brigadier/tests/command_suggestions_test.rs
new file mode 100644
index 00000000..8b137891
--- /dev/null
+++ b/azalea-brigadier/tests/command_suggestions_test.rs
@@ -0,0 +1 @@
+
diff --git a/azalea-brigadier/tests/context/command_context_test.rs b/azalea-brigadier/tests/context/command_context_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/context/command_context_test.rs
diff --git a/azalea-brigadier/tests/context/parsed_argument_test.rs b/azalea-brigadier/tests/context/parsed_argument_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/context/parsed_argument_test.rs
diff --git a/azalea-brigadier/tests/exceptions/dynamic_command_syntax_exception_type_test.rs b/azalea-brigadier/tests/exceptions/dynamic_command_syntax_exception_type_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/exceptions/dynamic_command_syntax_exception_type_test.rs
diff --git a/azalea-brigadier/tests/exceptions/simple_command_syntax_exception_type_test.rs b/azalea-brigadier/tests/exceptions/simple_command_syntax_exception_type_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/exceptions/simple_command_syntax_exception_type_test.rs
diff --git a/azalea-brigadier/tests/string_reader_test.rs b/azalea-brigadier/tests/string_reader_test.rs
new file mode 100644
index 00000000..5008eff8
--- /dev/null
+++ b/azalea-brigadier/tests/string_reader_test.rs
@@ -0,0 +1,612 @@
+use azalea_brigadier::{exceptions::BuiltInExceptions, string_reader::StringReader};
+
+#[test]
+fn can_read() {
+    let mut reader = StringReader::from("abc".to_string());
+    assert_eq!(reader.can_read(), true);
+    reader.skip(); // 'a'
+    assert_eq!(reader.can_read(), true);
+    reader.skip(); // 'b'
+    assert_eq!(reader.can_read(), true);
+    reader.skip(); // 'c'
+    assert_eq!(reader.can_read(), false);
+}
+
+#[test]
+fn get_remaining_length() {
+    let mut reader = StringReader::from("abc".to_string());
+    assert_eq!(reader.remaining_length(), 3);
+    reader.cursor = 1;
+    assert_eq!(reader.remaining_length(), 2);
+    reader.cursor = 2;
+    assert_eq!(reader.remaining_length(), 1);
+    reader.cursor = 3;
+    assert_eq!(reader.remaining_length(), 0);
+}
+
+#[test]
+fn can_read_length() {
+    let reader = StringReader::from("abc".to_string());
+    assert_eq!(reader.can_read_length(1), true);
+    assert_eq!(reader.can_read_length(2), true);
+    assert_eq!(reader.can_read_length(3), true);
+    assert_eq!(reader.can_read_length(4), false);
+    assert_eq!(reader.can_read_length(5), false);
+}
+
+#[test]
+fn peek() {
+    let mut reader = StringReader::from("abc".to_string());
+    assert_eq!(reader.peek(), 'a');
+    assert_eq!(reader.cursor(), 0);
+    reader.cursor = 2;
+    assert_eq!(reader.peek(), 'c');
+    assert_eq!(reader.cursor(), 2);
+}
+
+#[test]
+fn peek_length() {
+    let mut reader = StringReader::from("abc".to_string());
+    assert_eq!(reader.peek_offset(0), 'a');
+    assert_eq!(reader.peek_offset(2), 'c');
+    assert_eq!(reader.cursor(), 0);
+    reader.cursor = 1;
+    assert_eq!(reader.peek_offset(1), 'c');
+    assert_eq!(reader.cursor(), 1);
+}
+
+#[test]
+fn read() {
+    let mut reader = StringReader::from("abc".to_string());
+    assert_eq!(reader.read(), 'a');
+    assert_eq!(reader.read(), 'b');
+    assert_eq!(reader.read(), 'c');
+    assert_eq!(reader.cursor(), 3);
+}
+
+#[test]
+fn skip() {
+    let mut reader = StringReader::from("abc".to_string());
+    reader.skip();
+    assert_eq!(reader.cursor(), 1);
+}
+
+#[test]
+fn get_remaining() {
+    let mut reader = StringReader::from("Hello!".to_string());
+    assert_eq!(reader.remaining(), "Hello!");
+    reader.cursor = 3;
+    assert_eq!(reader.remaining(), "lo!");
+    reader.cursor = 6;
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn get_read() {
+    let mut reader = StringReader::from("Hello!".to_string());
+    assert_eq!(reader.get_read(), "");
+    reader.cursor = 3;
+    assert_eq!(reader.get_read(), "Hel");
+    reader.cursor = 6;
+    assert_eq!(reader.get_read(), "Hello!");
+}
+
+#[test]
+fn skip_whitespace_none() {
+    let mut reader = StringReader::from("Hello!".to_string());
+    reader.skip_whitespace();
+    assert_eq!(reader.cursor(), 0);
+}
+
+#[test]
+fn skip_whitespace_mixed() {
+    let mut reader = StringReader::from(" \t \t\nHello!".to_string());
+    reader.skip_whitespace();
+    assert_eq!(reader.cursor(), 5);
+}
+
+#[test]
+fn skip_whitespace_empty() {
+    let mut reader = StringReader::from("".to_string());
+    reader.skip_whitespace();
+    assert_eq!(reader.cursor(), 0);
+}
+
+#[test]
+fn read_unquoted_string() {
+    let mut reader = StringReader::from("hello world".to_string());
+    assert_eq!(reader.read_unquoted_string(), "hello");
+    assert_eq!(reader.get_read(), "hello");
+    assert_eq!(reader.remaining(), " world");
+}
+
+#[test]
+fn read_unquoted_string_empty() {
+    let mut reader = StringReader::from("".to_string());
+    assert_eq!(reader.read_unquoted_string(), "");
+    assert_eq!(reader.get_read(), "");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_unquoted_string_empty_with_remaining() {
+    let mut reader = StringReader::from(" hello world".to_string());
+    assert_eq!(reader.read_unquoted_string(), "");
+    assert_eq!(reader.get_read(), "");
+    assert_eq!(reader.remaining(), " hello world");
+}
+
+#[test]
+fn read_quoted_string() {
+    let mut reader = StringReader::from("\"hello world\"".to_string());
+    assert_eq!(reader.read_quoted_string().unwrap(), "hello world");
+    assert_eq!(reader.get_read(), "\"hello world\"");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_single_quoted_string() {
+    let mut reader = StringReader::from("'hello world'".to_string());
+    assert_eq!(reader.read_quoted_string().unwrap(), "hello world");
+    assert_eq!(reader.get_read(), "'hello world'");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_mixed_quoted_string_double_inside_single() {
+    let mut reader = StringReader::from("'hello \"world\"'".to_string());
+    assert_eq!(reader.read_quoted_string().unwrap(), "hello \"world\"");
+    assert_eq!(reader.get_read(), "'hello \"world\"'");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_mixed_quoted_string_single_inside_double() {
+    let mut reader = StringReader::from("\"hello 'world'\"".to_string());
+    assert_eq!(reader.read_quoted_string().unwrap(), "hello 'world'");
+    assert_eq!(reader.get_read(), "\"hello 'world'\"");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_quoted_string_empty_quoted() {
+    let mut reader = StringReader::from("".to_string());
+    assert_eq!(reader.read_quoted_string().unwrap(), "");
+    assert_eq!(reader.get_read(), "");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_quoted_string_empty_quoted_with_remaining() {
+    let mut reader = StringReader::from("\"\" hello world".to_string());
+    assert_eq!(reader.read_quoted_string().unwrap(), "");
+    assert_eq!(reader.get_read(), "\"\"");
+    assert_eq!(reader.remaining(), " hello world");
+}
+
+#[test]
+fn read_quoted_string_with_escaped_quote() {
+    let mut reader = StringReader::from("\"hello \\\"world\\\"\"".to_string());
+    assert_eq!(reader.read_quoted_string().unwrap(), "hello \"world\"");
+    assert_eq!(reader.get_read(), "\"hello \\\"world\\\"\"");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_quoted_string_with_escaped_escapes() {
+    let mut reader = StringReader::from("\"\\\\o/\"".to_string());
+    assert_eq!(reader.read_quoted_string().unwrap(), "\\o/");
+    assert_eq!(reader.get_read(), "\"\\\\o/\"");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_quoted_string_with_remaining() {
+    let mut reader = StringReader::from("\"hello world\" foo bar".to_string());
+    assert_eq!(reader.read_quoted_string().unwrap(), "hello world");
+    assert_eq!(reader.get_read(), "\"hello world\"");
+    assert_eq!(reader.remaining(), " foo bar");
+}
+
+#[test]
+fn read_quoted_string_with_immediate_remaining() {
+    let mut reader = StringReader::from("\"hello world\"foo bar".to_string());
+    assert_eq!(reader.read_quoted_string().unwrap(), "hello world");
+    assert_eq!(reader.get_read(), "\"hello world\"");
+    assert_eq!(reader.remaining(), "foo bar");
+}
+
+#[test]
+fn read_quoted_string_no_open() {
+    let mut reader = StringReader::from("hello world\"".to_string());
+    let result = reader.read_quoted_string();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(e.get_type(), &BuiltInExceptions::ReaderExpectedStartOfQuote);
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn read_quoted_string_no_close() {
+    let mut reader = StringReader::from("\"hello world".to_string());
+    let result = reader.read_quoted_string();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(e.get_type(), &BuiltInExceptions::ReaderExpectedEndOfQuote);
+        assert_eq!(e.cursor(), Some(12));
+    }
+}
+
+#[test]
+fn read_quoted_string_invalid_escape() {
+    let mut reader = StringReader::from("\"hello\\nworld\"".to_string());
+    let result = reader.read_quoted_string();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(
+            e.get_type(),
+            &BuiltInExceptions::ReaderInvalidEscape { character: 'n' }
+        );
+        assert_eq!(e.cursor(), Some(7));
+    }
+}
+
+#[test]
+fn read_quoted_string_invalid_quote_escape() {
+    let mut reader = StringReader::from("'hello\\\"\'world".to_string());
+    let result = reader.read_quoted_string();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(
+            e.get_type(),
+            &BuiltInExceptions::ReaderInvalidEscape { character: '"' }
+        );
+        assert_eq!(e.cursor(), Some(7));
+    }
+}
+
+#[test]
+fn read_string_no_quotes() {
+    let mut reader = StringReader::from("hello world".to_string());
+    assert_eq!(reader.read_string().unwrap(), "hello");
+    assert_eq!(reader.get_read(), "hello");
+    assert_eq!(reader.remaining(), " world");
+}
+
+#[test]
+fn read_string_single_quotes() {
+    let mut reader = StringReader::from("'hello world'".to_string());
+    assert_eq!(reader.read_string().unwrap(), "hello world");
+    assert_eq!(reader.get_read(), "'hello world'");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_string_double_quotes() {
+    let mut reader = StringReader::from("\"hello world\"".to_string());
+    assert_eq!(reader.read_string().unwrap(), "hello world");
+    assert_eq!(reader.get_read(), "\"hello world\"");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_int() {
+    let mut reader = StringReader::from("1234567890".to_string());
+    assert_eq!(reader.read_int().unwrap(), 1234567890);
+    assert_eq!(reader.get_read(), "1234567890");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_int_negative() {
+    let mut reader = StringReader::from("-1234567890".to_string());
+    assert_eq!(reader.read_int().unwrap(), -1234567890);
+    assert_eq!(reader.get_read(), "-1234567890");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_int_invalid() {
+    let mut reader = StringReader::from("12.34".to_string());
+    let result = reader.read_int();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(
+            e.get_type(),
+            &BuiltInExceptions::ReaderInvalidInt {
+                value: "12.34".to_string()
+            }
+        );
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn read_int_none() {
+    let mut reader = StringReader::from("".to_string());
+    let result = reader.read_int();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(e.get_type(), &BuiltInExceptions::ReaderExpectedInt);
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn read_int_with_remaining() {
+    let mut reader = StringReader::from("1234567890 foo bar".to_string());
+    assert_eq!(reader.read_int().unwrap(), 1234567890);
+    assert_eq!(reader.get_read(), "1234567890");
+    assert_eq!(reader.remaining(), " foo bar");
+}
+
+#[test]
+fn read_int_with_remaining_immediate() {
+    let mut reader = StringReader::from("1234567890foo bar".to_string());
+    assert_eq!(reader.read_int().unwrap(), 1234567890);
+    assert_eq!(reader.get_read(), "1234567890");
+    assert_eq!(reader.remaining(), "foo bar");
+}
+
+#[test]
+fn read_long() {
+    let mut reader = StringReader::from("1234567890".to_string());
+    assert_eq!(reader.read_long().unwrap(), 1234567890);
+    assert_eq!(reader.get_read(), "1234567890");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_long_negative() {
+    let mut reader = StringReader::from("-1234567890".to_string());
+    assert_eq!(reader.read_long().unwrap(), -1234567890);
+    assert_eq!(reader.get_read(), "-1234567890");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_long_invalid() {
+    let mut reader = StringReader::from("12.34".to_string());
+    let result = reader.read_long();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(
+            e.get_type(),
+            &BuiltInExceptions::ReaderInvalidLong {
+                value: "12.34".to_string()
+            }
+        );
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn read_long_none() {
+    let mut reader = StringReader::from("".to_string());
+    let result = reader.read_long();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(e.get_type(), &BuiltInExceptions::ReaderExpectedLong);
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn read_long_with_remaining() {
+    let mut reader = StringReader::from("1234567890 foo bar".to_string());
+    assert_eq!(reader.read_long().unwrap(), 1234567890);
+    assert_eq!(reader.get_read(), "1234567890");
+    assert_eq!(reader.remaining(), " foo bar");
+}
+
+#[test]
+fn read_long_with_remaining_immediate() {
+    let mut reader = StringReader::from("1234567890foo bar".to_string());
+    assert_eq!(reader.read_long().unwrap(), 1234567890);
+    assert_eq!(reader.get_read(), "1234567890");
+    assert_eq!(reader.remaining(), "foo bar");
+}
+
+#[test]
+fn read_double() {
+    let mut reader = StringReader::from("123".to_string());
+    assert_eq!(reader.read_double().unwrap(), 123.0);
+    assert_eq!(reader.get_read(), "123");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_double_with_decimal() {
+    let mut reader = StringReader::from("12.34".to_string());
+    assert_eq!(reader.read_double().unwrap(), 12.34);
+    assert_eq!(reader.get_read(), "12.34");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_double_negative() {
+    let mut reader = StringReader::from("-123".to_string());
+    assert_eq!(reader.read_double().unwrap(), -123.0);
+    assert_eq!(reader.get_read(), "-123");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_double_invalid() {
+    let mut reader = StringReader::from("12.34.56".to_string());
+    let result = reader.read_double();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(
+            e.get_type(),
+            &BuiltInExceptions::ReaderInvalidDouble {
+                value: "12.34.56".to_string()
+            }
+        );
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn read_double_none() {
+    let mut reader = StringReader::from("".to_string());
+    let result = reader.read_double();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(e.get_type(), &BuiltInExceptions::ReaderExpectedDouble);
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn read_double_with_remaining() {
+    let mut reader = StringReader::from("12.34 foo bar".to_string());
+    assert_eq!(reader.read_double().unwrap(), 12.34);
+    assert_eq!(reader.get_read(), "12.34");
+    assert_eq!(reader.remaining(), " foo bar");
+}
+
+#[test]
+fn read_double_with_remaining_immediate() {
+    let mut reader = StringReader::from("12.34foo bar".to_string());
+    assert_eq!(reader.read_double().unwrap(), 12.34);
+    assert_eq!(reader.get_read(), "12.34");
+    assert_eq!(reader.remaining(), "foo bar");
+}
+
+#[test]
+fn read_float() {
+    let mut reader = StringReader::from("123".to_string());
+    assert_eq!(reader.read_float().unwrap(), 123.0f32);
+    assert_eq!(reader.get_read(), "123");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_float_with_decimal() {
+    let mut reader = StringReader::from("12.34".to_string());
+    assert_eq!(reader.read_float().unwrap(), 12.34f32);
+    assert_eq!(reader.get_read(), "12.34");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_float_negative() {
+    let mut reader = StringReader::from("-123".to_string());
+    assert_eq!(reader.read_float().unwrap(), -123.0f32);
+    assert_eq!(reader.get_read(), "-123");
+    assert_eq!(reader.remaining(), "");
+}
+
+#[test]
+fn read_float_invalid() {
+    let mut reader = StringReader::from("12.34.56".to_string());
+    let result = reader.read_float();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(
+            e.get_type(),
+            &BuiltInExceptions::ReaderInvalidFloat {
+                value: "12.34.56".to_string()
+            }
+        );
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn read_float_none() {
+    let mut reader = StringReader::from("".to_string());
+    let result = reader.read_float();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(e.get_type(), &BuiltInExceptions::ReaderExpectedFloat);
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn read_float_with_remaining() {
+    let mut reader = StringReader::from("12.34 foo bar".to_string());
+    assert_eq!(reader.read_float().unwrap(), 12.34f32);
+    assert_eq!(reader.get_read(), "12.34");
+    assert_eq!(reader.remaining(), " foo bar");
+}
+
+#[test]
+fn read_float_with_remaining_immediate() {
+    let mut reader = StringReader::from("12.34foo bar".to_string());
+    assert_eq!(reader.read_float().unwrap(), 12.34f32);
+    assert_eq!(reader.get_read(), "12.34");
+    assert_eq!(reader.remaining(), "foo bar");
+}
+
+#[test]
+fn expect_correct() {
+    let mut reader = StringReader::from("abc".to_string());
+    reader.expect('a').unwrap();
+    assert_eq!(reader.cursor(), 1);
+}
+
+#[test]
+fn expect_incorrect() {
+    let mut reader = StringReader::from("bcd".to_string());
+    let result = reader.expect('a');
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(
+            e.get_type(),
+            &BuiltInExceptions::ReaderExpectedSymbol { symbol: 'a' }
+        );
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn expect_none() {
+    let mut reader = StringReader::from("".to_string());
+    let result = reader.expect('a');
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(
+            e.get_type(),
+            &BuiltInExceptions::ReaderExpectedSymbol { symbol: 'a' }
+        );
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn read_boolean_correct() {
+    let mut reader = StringReader::from("true".to_string());
+    assert_eq!(reader.read_boolean().unwrap(), true);
+    assert_eq!(reader.get_read(), "true");
+}
+
+#[test]
+fn read_boolean_incorrect() {
+    let mut reader = StringReader::from("tuesday".to_string());
+    let result = reader.read_boolean();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(
+            e.get_type(),
+            &BuiltInExceptions::ReaderInvalidBool {
+                value: "tuesday".to_string()
+            }
+        );
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
+
+#[test]
+fn read_boolean_none() {
+    let mut reader = StringReader::from("".to_string());
+    let result = reader.read_boolean();
+    assert!(result.is_err());
+    if let Err(e) = result {
+        assert_eq!(e.get_type(), &BuiltInExceptions::ReaderExpectedBool);
+        assert_eq!(e.cursor(), Some(0));
+    }
+}
diff --git a/azalea-brigadier/tests/suggestion/suggestion_test.rs b/azalea-brigadier/tests/suggestion/suggestion_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/suggestion/suggestion_test.rs
diff --git a/azalea-brigadier/tests/suggestion/suggestions_builder_test.rs b/azalea-brigadier/tests/suggestion/suggestions_builder_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/suggestion/suggestions_builder_test.rs
diff --git a/azalea-brigadier/tests/suggestion/suggestions_test.rs b/azalea-brigadier/tests/suggestion/suggestions_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/suggestion/suggestions_test.rs
diff --git a/azalea-brigadier/tests/tree/abstract_command_node_test.rs b/azalea-brigadier/tests/tree/abstract_command_node_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/tree/abstract_command_node_test.rs
diff --git a/azalea-brigadier/tests/tree/argument_command_node_test.rs b/azalea-brigadier/tests/tree/argument_command_node_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/tree/argument_command_node_test.rs
diff --git a/azalea-brigadier/tests/tree/literal_command_node_test.rs b/azalea-brigadier/tests/tree/literal_command_node_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/tree/literal_command_node_test.rs
diff --git a/azalea-brigadier/tests/tree/root_command_node_test.rs b/azalea-brigadier/tests/tree/root_command_node_test.rs
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/azalea-brigadier/tests/tree/root_command_node_test.rs
diff --git a/azalea-protocol/src/packets/game/clientbound_declare_commands_packet.rs b/azalea-protocol/src/packets/game/clientbound_declare_commands_packet.rs
new file mode 100644
index 00000000..1bcf0dd4
--- /dev/null
+++ b/azalea-protocol/src/packets/game/clientbound_declare_commands_packet.rs
@@ -0,0 +1,37 @@
+// use std::hash::Hash;
+
+// use crate::mc_buf::Readable;
+
+// use super::LoginPacket;
+
+// #[derive(Hash, Clone, Debug)]
+// pub struct ClientboundDeclareCommandsPacket {
+//     pub root: RootCommandNode<SharedSuggestionProvider>,
+//     pub public_key: Vec<u8>,
+//     pub nonce: Vec<u8>,
+// }
+
+// impl ClientboundHelloPacket {
+//     pub fn get(self) -> LoginPacket {
+//         LoginPacket::ClientboundHelloPacket(self)
+//     }
+
+//     pub fn write(&self, _buf: &mut Vec<u8>) -> Result<(), std::io::Error> {
+//         panic!("ClientboundHelloPacket::write not implemented")
+//     }
+
+//     pub async fn read<T: tokio::io::AsyncRead + std::marker::Unpin + std::marker::Send>(
+//         buf: &mut T,
+//     ) -> Result<LoginPacket, String> {
+//         let server_id = buf.read_utf_with_len(20).await?;
+//         let public_key = buf.read_byte_array().await?;
+//         let nonce = buf.read_byte_array().await?;
+
+//         Ok(ClientboundHelloPacket {
+//             server_id,
+//             public_key,
+//             nonce,
+//         }
+//         .get())
+//     }
+// }