Merge pull request 'Reintroduce integrated scripting language' (#52) from coralscript-mvp/reintroduction into main

Reviewed-on: #52

src/coral/coral.zig

@@ -4,7 +4,7 @@ pub const dag = @import("./dag.zig");
 
 pub const debug = @import("./debug.zig");
 
-pub const hash = @import("./hash.zig");
+pub const hashes = @import("./hashes.zig");
 
 pub const heap = @import("./heap.zig");
 

src/coral/io.zig

@@ -14,6 +14,15 @@ pub const Error = error {
 	UnavailableResource,
 };
 
+pub fn FixedBuffer(comptime len: usize, comptime default_value: anytype) type {
+	const Value = @TypeOf(default_value);
+
+	return struct {
+		filled: usize = 0,
+		values: [len]Value = [_]Value{default_value} ** len,
+	};
+}
+
 pub fn Functor(comptime Output: type, comptime input_types: []const type) type {
 	const InputTuple = std.meta.Tuple(input_types);
 

src/coral/map.zig

@@ -1,6 +1,6 @@
 const coral = @import("./coral.zig");
 
-const hash = @import("./hash.zig");
+const hashes = @import("./hashes.zig");
 
 const io = @import("./io.zig");
 
@@ -257,11 +257,9 @@ pub fn enum_traits(comptime Enum: type) Traits(Enum) {
 }
 
 pub const string_traits = init: {
-	const djb2 = hash.djb2;
-
 	const strings = struct {
 		fn hash(value: []const u8) usize {
-			return djb2(@typeInfo(usize).Int, value);
+			return hashes.djb2(@typeInfo(usize).Int, value);
 		}
 	};
 

src/coral/script/Chunk.zig

@@ -0,0 +1,998 @@
+const coral = @import("coral");
+
+const file = @import("../file.zig");
+
+const script = @import("../script.zig");
+
+const std = @import("std");
+
+const tokens = @import("./tokens.zig");
+
+const tree = @import("./tree.zig");
+
+name: *script.Object,
+arity: u8,
+opcodes: coral.Stack(Opcode),
+lines: coral.Stack(tokens.Line),
+cursor: usize,
+constants: coral.Stack(*script.Object),
+bindings: []?*script.Object,
+externals: *script.Object,
+
+const Compiler = struct {
+	chunk: *Self,
+	env: *script.Runtime,
+
+	fn compile_argument(self: *const Compiler, environment: *const tree.Environment, initial_argument: ?*const tree.Expr) script.Error!u8 {
+		// TODO: Exceeding 255 arguments will make the VM crash.
+		var maybe_argument = initial_argument;
+		var argument_count = @as(u8, 0);
+
+		while (maybe_argument) |argument| {
+			try self.compile_expression(environment, argument, null);
+
+			maybe_argument = argument.next;
+			argument_count += 1;
+		}
+
+		return argument_count;
+	}
+
+	fn compile_expression(self: *const Compiler, environment: *const tree.Environment, expression: *const tree.Expr, name: ?[]const u8) script.Error!void {
+		const number_format = coral.utf8.DecimalFormat{
+			.delimiter = "_",
+			.positive_prefix = .none,
+		};
+
+		switch (expression.kind) {
+			.nil_literal => try self.chunk.write(expression.line, .push_nil),
+			.true_literal => try self.chunk.write(expression.line, .push_true),
+			.false_literal => try self.chunk.write(expression.line, .push_false),
+
+			.number_literal => |literal| {
+				for (literal) |codepoint| {
+					if (codepoint == '.') {
+						return self.chunk.write(expression.line, .{
+							.push_const = try self.declare_float(number_format.parse(literal, script.Float) orelse unreachable),
+						});
+					}
+				}
+
+				try self.chunk.write(expression.line, .{
+					.push_const = try self.declare_fixed(number_format.parse(literal, script.Fixed) orelse unreachable),
+				});
+			},
+
+			.string_literal => |literal| {
+				try self.chunk.write(expression.line, .{.push_const = try self.declare_string(literal)});
+			},
+
+			.vector2 => |vector2| {
+				try self.compile_expression(environment, vector2.x, null);
+				try self.compile_expression(environment, vector2.y, null);
+				try self.chunk.write(expression.line, .push_vector2);
+			},
+
+			.vector3 => |vector3| {
+				try self.compile_expression(environment, vector3.x, null);
+				try self.compile_expression(environment, vector3.y, null);
+				try self.compile_expression(environment, vector3.z, null);
+				try self.chunk.write(expression.line, .push_vector3);
+			},
+
+			.string_template => {
+				var current_expression = expression.next orelse {
+					return self.chunk.write(expression.line, .{.push_const = try self.declare_string("")});
+				};
+
+				var component_count = @as(u8, 0);
+
+				while (true) {
+					try self.compile_expression(environment, current_expression, null);
+
+					component_count += 1;
+
+					current_expression = current_expression.next orelse {
+						return self.chunk.write(expression.line, .{.push_concat = component_count});
+					};
+				}
+			},
+
+			.symbol_literal => |literal| {
+				try self.chunk.write(expression.line, .{.push_const = try self.declare_symbol(literal)});
+			},
+
+			.table => |table| {
+				var entries = table.nodes();
+				var num_entries = @as(u16, 0);
+
+				while (entries.next()) |entry| {
+					try self.compile_expression(environment, entry.key, null);
+					try self.compile_expression(environment, entry.value, null);
+
+					num_entries = coral.scalars.add(num_entries, 1) orelse {
+						return self.env.raise(error.OutOfMemory, "too many initializer values", .{});
+					};
+				}
+
+				try self.chunk.write(expression.line, .{.push_table = num_entries});
+			},
+
+			.lambda_construct => |lambda_construct| {
+				var chunk = try Self.init(self.env, name orelse "<lambda>", lambda_construct.environment, &.{});
+
+				errdefer chunk.deinit(self.env);
+
+				if (lambda_construct.environment.capture_count == 0) {
+					try self.chunk.write(expression.line, .{.push_const = try self.declare_chunk(chunk)});
+				} else {
+					const lambda_captures = lambda_construct.environment.get_captures();
+					var index = lambda_captures.len;
+
+					while (index != 0) {
+						index -= 1;
+
+						try self.chunk.write(expression.line, switch (lambda_captures[index]) {
+							.declaration_index => |declaration_index| .{.push_local = declaration_index},
+							.capture_index => |capture_index| .{.push_binding = capture_index},
+						});
+					}
+
+					try self.chunk.write(expression.line, .{.push_const = try self.declare_chunk(chunk)});
+					try self.chunk.write(expression.line, .{.bind = lambda_construct.environment.capture_count});
+				}
+			},
+
+			.binary_op => |binary_op| {
+				try self.compile_expression(environment, binary_op.lhs_operand, null);
+				try self.compile_expression(environment, binary_op.rhs_operand, null);
+
+				try self.chunk.write(expression.line, switch (binary_op.operation) {
+					.addition => .add,
+					.subtraction => .sub,
+					.multiplication => .mul,
+					.divsion => .div,
+					.greater_equals_comparison => .cge,
+					.greater_than_comparison => .cgt,
+					.equals_comparison => .eql,
+					.less_than_comparison => .clt,
+					.less_equals_comparison => .cle,
+				});
+			},
+
+			.unary_op => |unary_op| {
+				try self.compile_expression(environment, unary_op.operand, null);
+
+				try self.chunk.write(expression.line, switch (unary_op.operation) {
+					.boolean_negation => .not,
+					.numeric_negation => .neg,
+				});
+			},
+
+			.invoke => |invoke| {
+				const argument_count = try self.compile_argument(environment, invoke.argument);
+
+				try self.compile_expression(environment, invoke.object, null);
+				try self.chunk.write(expression.line, .{.call = argument_count});
+			},
+
+			.group => |group| try self.compile_expression(environment, group, null),
+
+			.declaration_get => |declaration_get| {
+				if (get_local_index(environment, declaration_get.declaration)) |index| {
+					if (is_declaration_boxed(declaration_get.declaration)) {
+						try self.chunk.write(expression.line, .{.push_local = index});
+						try self.chunk.write(expression.line, .get_box);
+					} else {
+						try self.chunk.write(expression.line, .{.push_local = index});
+					}
+
+					return;
+				}
+
+				if (try get_binding_index(environment, declaration_get.declaration)) |index| {
+					try self.chunk.write(expression.line, .{.push_binding = index});
+
+					if (is_declaration_boxed(declaration_get.declaration)) {
+						try self.chunk.write(expression.line, .get_box);
+					}
+
+					return;
+				}
+
+				return self.env.raise(error.IllegalState, "local out of scope", .{});
+			},
+
+			.declaration_set => |declaration_set| {
+				if (get_local_index(environment, declaration_set.declaration)) |index| {
+					if (is_declaration_boxed(declaration_set.declaration)) {
+						try self.chunk.write(expression.line, .{.push_local = index});
+						try self.compile_expression(environment, declaration_set.assign, null);
+						try self.chunk.write(expression.line, .set_box);
+					} else {
+						try self.compile_expression(environment, declaration_set.assign, null);
+						try self.chunk.write(expression.line, .{.set_local = index});
+					}
+
+					return;
+				}
+
+				if (try get_binding_index(environment, declaration_set.declaration)) |index| {
+					try self.compile_expression(environment, declaration_set.assign, null);
+					try self.chunk.write(expression.line, .{.push_binding = index});
+
+					if (is_declaration_boxed(declaration_set.declaration)) {
+						try self.chunk.write(expression.line, .set_box);
+					}
+
+					return;
+				}
+
+				return self.env.raise(error.IllegalState, "local out of scope", .{});
+			},
+
+			.field_get => |field_get| {
+				try self.chunk.write(expression.line, .{.push_const = try self.declare_symbol(field_get.identifier)});
+				try self.compile_expression(environment, field_get.object, null);
+				try self.chunk.write(expression.line, .get_dynamic);
+			},
+
+			.field_set => |field_set| {
+				try self.chunk.write(expression.line, .{.push_const = try self.declare_symbol(field_set.identifier)});
+				try self.compile_expression(environment, field_set.assign, null);
+				try self.compile_expression(environment, field_set.object, null);
+				try self.chunk.write(expression.line, .set_dynamic);
+			},
+
+			.subscript_get => |subscript_get| {
+				try self.compile_expression(environment, subscript_get.index, null);
+				try self.compile_expression(environment, subscript_get.object, null);
+				try self.chunk.write(expression.line, .get_dynamic);
+			},
+
+			.subscript_set => |subscript_set| {
+				try self.compile_expression(environment, subscript_set.index, null);
+				try self.compile_expression(environment, subscript_set.assign, null);
+				try self.compile_expression(environment, subscript_set.object, null);
+				try self.chunk.write(expression.line, .set_dynamic);
+			},
+
+			.external_get => |external_get| {
+				try self.chunk.write(expression.line, .{.push_const = try self.declare_symbol(external_get.name)});
+				try self.chunk.write(expression.line, .get_external);
+			},
+		}
+	}
+
+	pub fn compile_environment(self: *const Compiler, environment: *const tree.Environment) script.Error!void {
+		if (environment.statement) |statement| {
+			const last_statement = try self.compile_statement(environment, statement);
+
+			if (last_statement.kind != .@"return") {
+				try self.chunk.write(last_statement.line, .push_nil);
+			}
+		}
+	}
+
+	fn compile_statement(self: *const Compiler, environment: *const tree.Environment, initial_statement: *const tree.Stmt) script.Error!*const tree.Stmt {
+		var current_statement = initial_statement;
+
+		while (true) {
+			switch (current_statement.kind) {
+				.@"return" => |@"return"| {
+					if (@"return".returned_expression) |expression| {
+						try self.compile_expression(environment, expression, null);
+					} else {
+						try self.chunk.write(current_statement.line, .push_nil);
+					}
+
+					// TODO: Omit ret calls at ends of chunk.
+					try self.chunk.write(current_statement.line, .ret);
+				},
+
+				.@"while" => |@"while"| {
+					try self.compile_expression(environment, @"while".loop_expression, null);
+					try self.chunk.write(current_statement.line, .{.jf = 0});
+
+					const origin_index = @as(u16, @intCast(self.chunk.opcodes.values.len - 1));
+
+					_ = try self.compile_statement(environment, @"while".loop);
+					self.chunk.opcodes.values[origin_index].jf = @intCast(self.chunk.opcodes.values.len - 1);
+
+					try self.compile_expression(environment, @"while".loop_expression, null);
+					try self.chunk.write(current_statement.line, .{.jt = origin_index});
+				},
+
+				.@"if" => |@"if"| {
+					try self.compile_expression(environment, @"if".then_expression, null);
+					try self.chunk.write(current_statement.line, .{.jf = 0});
+
+					const origin_index = @as(u16, @intCast(self.chunk.opcodes.values.len - 1));
+
+					_ = try self.compile_statement(environment, @"if".@"then");
+					self.chunk.opcodes.values[origin_index].jf = @intCast(self.chunk.opcodes.values.len - 1);
+
+					if (@"if".@"else") |@"else"| {
+						_ = try self.compile_statement(environment, @"else");
+					}
+				},
+
+				.declare => |declare| {
+					try self.compile_expression(environment, declare.initial_expression, declare.declaration.identifier);
+
+					if (is_declaration_boxed(declare.declaration)) {
+						try self.chunk.write(current_statement.line, .push_boxed);
+					}
+				},
+
+				.top_expression => |top_expression| {
+					try self.compile_expression(environment, top_expression, null);
+
+					if (top_expression.kind == .invoke) {
+						try self.chunk.write(current_statement.line, .pop);
+					}
+				},
+			}
+
+			current_statement = current_statement.next orelse return current_statement;
+		}
+	}
+
+	const constants_max = @as(usize, std.math.maxInt(u16));
+
+	fn declare_chunk(self: *const Compiler, chunk: Self) script.Error!u16 {
+		if (self.chunk.constants.values.len == std.math.maxInt(u16)) {
+			return self.env.raise(error.BadSyntax, "chunks cannot contain more than {max} constants", .{
+				.max = @as(usize, std.math.maxInt(u16)),
+			});
+		}
+
+		const constant = (try self.env.new_dynamic(chunk)).pop().?;
+
+		errdefer self.env.release(constant);
+
+		try self.chunk.constants.push(constant);
+
+		return @intCast(self.chunk.constants.values.len - 1);
+	}
+
+	fn declare_fixed(self: *const Compiler, fixed: script.Fixed) script.Error!u16 {
+		if (self.chunk.constants.values.len == constants_max) {
+			return self.env.raise(error.BadSyntax, "chunks cannot contain more than {max} constants", .{
+				.max = constants_max,
+			});
+		}
+
+		const constant = (try self.env.new_fixed(fixed)).pop().?;
+
+		errdefer self.env.release(constant);
+
+		try self.chunk.constants.push(constant);
+
+		return @intCast(self.chunk.constants.values.len - 1);
+	}
+
+	fn declare_float(self: *const Compiler, float: script.Float) script.Error!u16 {
+		if (self.chunk.constants.values.len == constants_max) {
+			return self.env.raise(error.BadSyntax, "chunks cannot contain more than {max} constants", .{
+				.max = constants_max,
+			});
+		}
+
+		const constant = (try self.env.new_float(float)).pop().?;
+
+		errdefer self.env.release(constant);
+
+		try self.chunk.constants.push(constant);
+
+		return @intCast(self.chunk.constants.values.len - 1);
+	}
+
+	fn declare_string(self: *const Compiler, string: []const u8) script.Error!u16 {
+		if (self.chunk.constants.values.len == constants_max) {
+			return self.env.raise(error.BadSyntax, "chunks cannot contain more than {max} constants", .{
+				.max = constants_max,
+			});
+		}
+
+		const constant = (try self.env.new_string(string)).pop().?;
+
+		errdefer self.env.release(constant);
+
+		try self.chunk.constants.push(constant);
+
+		return @intCast(self.chunk.constants.values.len - 1);
+	}
+
+	fn declare_vector2(self: *const Compiler, vector: script.Vector2) script.Error!u16 {
+		if (self.chunk.constants.values.len == constants_max) {
+			return self.env.raise(error.BadSyntax, "chunks cannot contain more than {max} constants", .{
+				.max = constants_max,
+			});
+		}
+
+		const constant = (try self.env.new_vector2(vector)).pop().?;
+
+		errdefer self.env.release(constant);
+
+		try self.chunk.constants.push(constant);
+
+		return @intCast(self.chunk.constants.values.len - 1);
+	}
+
+	fn declare_vector3(self: *const Compiler, vector: script.Vector3) script.Error!u16 {
+		if (self.chunk.constants.values.len == constants_max) {
+			return self.env.raise(error.BadSyntax, "chunks cannot contain more than {max} constants", .{
+				.max = constants_max,
+			});
+		}
+
+		const constant = (try self.env.new_vector3(vector)).pop().?;
+
+		errdefer self.env.release(constant);
+
+		try self.chunk.constants.push(constant);
+
+		return @intCast(self.chunk.constants.values.len - 1);
+	}
+
+	fn declare_symbol(self: *const Compiler, symbol: []const u8) script.Error!u16 {
+		if (self.chunk.constants.values.len == constants_max) {
+			return self.env.raise(error.BadSyntax, "chunks cannot contain more than {max} constants", .{
+				.max = constants_max,
+			});
+		}
+
+		const constant = (try self.env.new_symbol(symbol)).pop().?;
+
+		errdefer self.env.release(constant);
+
+		try self.chunk.constants.push(constant);
+
+		return @intCast(self.chunk.constants.values.len - 1);
+	}
+
+	fn get_binding_index(environment: *const tree.Environment, declaration: *const tree.Declaration) script.Error!?u8 {
+		var binding_index = @as(u8, 0);
+
+		while (binding_index < environment.capture_count) : (binding_index += 1) {
+			var capture = &environment.captures[binding_index];
+			var target_environment = environment.enclosing orelse return null;
+
+			while (capture.* == .capture_index) {
+				capture = &target_environment.captures[capture.capture_index];
+				target_environment = target_environment.enclosing orelse return null;
+			}
+
+			std.debug.assert(capture.* == .declaration_index);
+
+			if (&target_environment.declarations[capture.declaration_index] == declaration) {
+				return binding_index;
+			}
+		}
+
+		return null;
+	}
+
+	fn get_local_index(environment: *const tree.Environment, declaration: *const tree.Declaration) ?u8 {
+		var remaining = environment.declaration_count;
+
+		while (remaining != 0) {
+			remaining -= 1;
+
+			if (&environment.declarations[remaining] == declaration) {
+				return remaining;
+			}
+		}
+
+		return null;
+	}
+
+	fn is_declaration_boxed(declaration: *const tree.Declaration) bool {
+		return declaration.is.captured and !declaration.is.readonly;
+	}
+};
+
+pub const Opcode = union (enum) {
+	ret,
+	pop,
+	push_nil,
+	push_true,
+	push_false,
+	push_const: u16,
+	push_local: u8,
+	push_top,
+	push_vector2,
+	push_vector3,
+	push_table: u16,
+	push_binding: u8,
+	push_concat: u8,
+	push_boxed,
+	set_local: u8,
+	get_dynamic,
+	set_dynamic,
+	get_external,
+	get_box,
+	set_box,
+	call: u8,
+	bind: u8,
+
+	not,
+	neg,
+
+	add,
+	sub,
+	mul,
+	div,
+
+	eql,
+	cgt,
+	clt,
+	cge,
+	cle,
+
+	jt: u16,
+	jf: u16,
+};
+
+pub const External = struct {[]const u8, *script.Object};
+
+const Self = @This();
+
+pub fn deinit(self: *Self, env: *script.Runtime) void {
+	while (self.constants.pop()) |constant| {
+		env.release(constant.*);
+	}
+
+	self.constants.deinit();
+	self.opcodes.deinit();
+	self.lines.deinit();
+	env.release(self.name);
+	env.release(self.externals);
+
+	if (self.bindings.len != 0) {
+		for (self.bindings) |binding| {
+			if (binding) |value| {
+				env.release(value);
+			}
+		}
+
+		env.allocator.free(self.bindings);
+	}
+
+	self.bindings = &.{};
+}
+
+pub fn dump(chunk: Self, env: *script.Runtime) script.Error!*script.Object {
+	var opcode_cursor = @as(u32, 0);
+	var buffer = coral.list.ByteStack.init(env.allocator);
+
+	defer buffer.deinit();
+
+	const writer = coral.list.stack_as_writer(&buffer);
+
+	_ = coral.utf8.print_string(writer, "\n");
+
+	while (opcode_cursor < chunk.opcodes.values.len) : (opcode_cursor += 1) {
+		_ = coral.utf8.print_formatted(writer, "[{instruction}]: ", .{.instruction = opcode_cursor});
+
+		_ = switch (chunk.opcodes.values[opcode_cursor]) {
+			.ret => coral.utf8.print_string(writer, "ret\n"),
+			.pop => coral.utf8.print_string(writer, "pop\n"),
+			.push_nil => coral.utf8.print_string(writer, "push nil\n"),
+			.push_true => coral.utf8.print_string(writer, "push true\n"),
+			.push_false => coral.utf8.print_string(writer, "push false\n"),
+
+			.push_const => |push_const| print: {
+				const string_ref = (try (try env.push(try chunk.get_constant(env, push_const))).to_string()).pop().?;
+
+				defer env.release(string_ref);
+
+				const string = string_ref.is_string();
+
+				break: print coral.utf8.print_formatted(writer, "push const ({value})\n", .{.value = string.?});
+			},
+
+			.push_local => |push_local| coral.utf8.print_formatted(writer, "push local ({local})\n", .{
+				.local = push_local,
+			}),
+
+			.push_top => coral.utf8.print_string(writer, "push top\n"),
+
+			.push_table => |push_table| coral.utf8.print_formatted(writer, "push table ({count})\n", .{
+				.count = push_table,
+			}),
+
+			.push_boxed => coral.utf8.print_string(writer, "push boxed\n"),
+
+			.push_binding => |push_binding| coral.utf8.print_formatted(writer, "push binding ({binding})\n", .{
+				.binding = push_binding,
+			}),
+
+			.push_concat => |push_concat| coral.utf8.print_formatted(writer, "push concat ({count})\n", .{
+				.count = push_concat,
+			}),
+
+			.push_builtin => |push_builtin| coral.utf8.print_formatted(writer, "push builtin ({builtin})\n", .{
+				.builtin = switch (push_builtin) {
+					.import => "import",
+					.print => "print",
+					.vec2 => "vec2",
+					.vec3 => "vec3",
+				},
+			}),
+
+			.bind => |bind| coral.utf8.print_formatted(writer, "bind ({count})\n", .{
+				.count = bind,
+			}),
+
+			.set_local => |local_set| coral.utf8.print_formatted(writer, "set local ({local})\n", .{
+				.local = local_set,
+			}),
+
+			.get_box => coral.utf8.print_string(writer, "get box\n"),
+			.set_box => coral.utf8.print_string(writer, "set box\n"),
+			.get_dynamic => coral.utf8.print_string(writer, "get dynamic\n"),
+			.set_dynamic => coral.utf8.print_string(writer, "set dynamic\n"),
+			.call => |call| coral.utf8.print_formatted(writer, "call ({count})\n", .{.count = call}),
+			.not => coral.utf8.print_string(writer, "not\n"),
+			.neg => coral.utf8.print_string(writer, "neg\n"),
+			.add => coral.utf8.print_string(writer, "add\n"),
+			.sub => coral.utf8.print_string(writer, "sub\n"),
+			.mul => coral.utf8.print_string(writer, "mul\n"),
+			.div => coral.utf8.print_string(writer, "div\n"),
+			.eql => coral.utf8.print_string(writer, "eql\n"),
+			.cgt => coral.utf8.print_string(writer, "cgt\n"),
+			.clt => coral.utf8.print_string(writer, "clt\n"),
+			.cge => coral.utf8.print_string(writer, "cge\n"),
+			.cle => coral.utf8.print_string(writer, "cle\n"),
+			.jf => |jf| coral.utf8.print_formatted(writer, "jf ({instruction})\n", .{.instruction = jf}),
+			.jt => |jt| coral.utf8.print_formatted(writer, "jt ({instruction})\n", .{.instruction = jt}),
+		};
+	}
+
+	return (try env.new_string(buffer.values)).pop().?;
+}
+
+pub fn execute(self: *Self, env: *script.Runtime) script.Error!?*script.Object {
+	self.cursor = 0;
+
+	while (self.cursor < self.opcodes.values.len) : (self.cursor += 1) {
+		switch (self.opcodes.values[self.cursor]) {
+			.ret => break,
+			.pop => env.discard(),
+			.push_nil => _ = try env.push(null),
+			.push_true => _ = try env.new_boolean(true),
+			.push_false => _ = try env.new_boolean(false),
+			.push_const => |push_const| _ = try env.push(try self.get_constant(env, push_const)),
+			.push_local => |push_local| _ = try env.local_get(push_local),
+			.push_top => _ = try env.local_top(),
+
+			.push_vector2 => {
+				const y = try env.expect_float(try env.expect_object(env.pop()));
+				const x = try env.expect_float(try env.expect_object(env.pop()));
+
+				_ = try env.new_vector2(.{@floatCast(x), @floatCast(y)});
+			},
+
+			.push_vector3 => {
+				const z = try env.expect_float(try env.expect_object(env.pop()));
+				const y = try env.expect_float(try env.expect_object(env.pop()));
+				const x = try env.expect_float(try env.expect_object(env.pop()));
+
+				_ =  try env.new_vector3(.{@floatCast(x), @floatCast(y), @floatCast(z)});
+			},
+
+			.push_table => |push_table| {
+				const table = (try env.new_table()).pop().?;
+
+				defer env.release(table);
+
+				var popped = @as(usize, 0);
+
+				while (popped < push_table) : (popped += 1) {
+					if (env.pop()) |object| {
+						defer env.release(object);
+
+						try env.index_set(table, object);
+					} else {
+						env.release(try env.expect_object(env.pop()));
+					}
+				}
+
+				_ = try env.push(table);
+			},
+
+			.push_boxed => {
+				const value = env.pop();
+
+				defer {
+					if (value) |object| {
+						env.release(object);
+					}
+				}
+
+				_ = try env.new_boxed(value);
+			},
+
+			.push_binding => |push_binding| _ = try env.push(try self.get_binding(env, push_binding)),
+			.push_concat => |push_concat| _ = try env.concat(push_concat),
+
+			.bind => |bind| {
+				const callable = try env.expect_object(env.pop());
+
+				defer env.release(callable);
+
+				const chunk = try env.expect_dynamic(callable, Self);
+
+				if (chunk.bindings.len != 0) {
+					return env.raise(error.IllegalState, "cannot bind values to an already-bound chunk", .{});
+				}
+
+				chunk.bindings = try env.allocator.alloc(?*script.Object, bind);
+
+				errdefer env.allocator.free(chunk.bindings);
+
+				for (0 .. bind) |index| {
+					const value = env.pop();
+
+					errdefer {
+						if (value) |object| {
+							env.release(object);
+						}
+					}
+
+					chunk.bindings[index] = value;
+				}
+
+				_ = try env.push(callable);
+			},
+
+			.set_local => |local_set| _ = try env.local_set(local_set, env.pop()),
+			.get_box => _ = try env.boxed_get(),
+
+			.set_box => {
+				const value = env.pop();
+
+				defer {
+					if (value) |object| {
+						env.release(object);
+					}
+				}
+
+				try env.boxed_set(value);
+			},
+
+			.get_dynamic => {
+				const indexable = try env.expect_object(env.pop());
+
+				defer env.release(indexable);
+
+				_ = try env.index_get(indexable);
+			},
+
+			.set_dynamic => {
+				const indexable = try env.expect_object(env.pop());
+
+				defer env.release(indexable);
+
+				const value = env.pop();
+
+				defer {
+					if (value) |object| {
+						env.release(object);
+					}
+				}
+
+				try env.index_set(indexable, value);
+			},
+
+			.get_external => _ = try env.index_get(self.externals),
+			.call => |call| _ = try env.call(call),
+
+			.not => {
+				const object = try env.expect_object(env.pop());
+
+				defer env.release(object);
+
+				_ = try env.new_boolean(object.is_false());
+			},
+
+			.neg => _ = try env.neg(),
+
+			.add => {
+				const addable = try env.expect_object(env.pop());
+
+				defer env.release(addable);
+
+				_ = switch (try env.expect_numeric(addable)) {
+					.fixed => |fixed| try env.fixed_add(fixed),
+					.float => |float| try env.float_add(float),
+					.vector2 => |vector2| try env.vector2_add(vector2),
+					.vector3 => |vector3| try env.vector3_add(vector3),
+				};
+			},
+
+			.sub => {
+				const subtractable = try env.expect_object(env.pop());
+
+				defer env.release(subtractable);
+
+				_ = switch (try env.expect_numeric(subtractable)) {
+					.fixed => |fixed| try env.fixed_subtract(fixed),
+					.float => |float| try env.float_subtract(float),
+					.vector2 => |vector2| try env.vector2_subtract(vector2),
+					.vector3 => |vector3| try env.vector3_subtract(vector3),
+				};
+			},
+
+			.mul => {
+				const multiplicable = try env.expect_object(env.pop());
+
+				defer env.release(multiplicable);
+
+				_ = switch (try env.expect_numeric(multiplicable)) {
+					.fixed => |fixed| try env.fixed_multiply(fixed),
+					.float => |float| try env.float_multiply(float),
+					.vector2 => |vector2| try env.vector2_multiply(vector2),
+					.vector3 => |vector3| try env.vector3_multiply(vector3),
+				};
+			},
+
+			.div => {
+				const divisible = try env.expect_object(env.pop());
+
+				defer env.release(divisible);
+
+				_ = switch (try env.expect_numeric(divisible)) {
+					.fixed => |fixed| try env.fixed_divide(fixed),
+					.float => |float| try env.float_divide(float),
+					.vector2 => |vector2| try env.vector2_divide(vector2),
+					.vector3 => |vector3| try env.vector3_divide(vector3),
+				};
+			},
+
+			.eql => {
+				if (env.pop()) |equatable| {
+					defer env.release(equatable);
+
+					_ = try env.equals_object(equatable);
+				} else {
+					_ = try env.equals_nil();
+				}
+			},
+
+			.cgt => {
+				const comparable = try env.expect_object(env.pop());
+
+				defer env.release(comparable);
+
+				_ = try env.compare_greater(comparable);
+			},
+
+			.clt => {
+				const comparable = try env.expect_object(env.pop());
+
+				defer env.release(comparable);
+
+				_ = try env.compare_less(comparable);
+			},
+
+			.cge => {
+				const comparable = try env.expect_object(env.pop());
+
+				defer env.release(comparable);
+
+				_ = try env.compare_greater_equals(comparable);
+			},
+
+			.cle => {
+				const comparable = try env.expect_object(env.pop());
+
+				defer env.release(comparable);
+
+				_ = try env.compare_less_equals(comparable);
+			},
+
+			.jf => |jf| {
+				if (env.pop()) |condition| {
+					defer env.release(condition);
+
+					if (condition.is_false()) {
+						self.cursor = jf;
+					}
+				} else {
+					self.cursor = jf;
+				}
+			},
+
+			.jt => |jt| {
+				if (env.pop()) |condition| {
+					defer env.release(condition);
+
+					if (condition.is_true()) {
+						self.cursor = jt;
+					}
+				}
+			},
+		}
+	}
+
+	return env.pop();
+}
+
+fn get_binding(self: *Self, env: *script.Runtime, index: usize) script.Error!?*script.Object {
+	if (index >= self.bindings.len) {
+		return env.raise(error.IllegalState, "invalid binding", .{});
+	}
+
+	return self.bindings[index];
+}
+
+fn get_constant(self: *const Self, env: *script.Runtime, index: usize) script.Error!*script.Object {
+	if (index >= self.constants.values.len) {
+		return env.raise(error.IllegalState, "invalid constant", .{});
+	}
+
+	return self.constants.values[index];
+}
+
+pub fn init(env: *script.Runtime, name: []const u8, environment: *const tree.Environment, externals: []const External) script.Error!Self {
+	const name_symbol = (try env.new_symbol(name)).pop().?;
+
+	errdefer env.release(name_symbol);
+
+	const externals_table = (try env.new_table()).pop().?;
+
+	errdefer env.release(externals_table);
+
+	for (0 .. externals.len) |i| {
+		const external_name, const external_object = externals[i];
+
+		try (try env.new_symbol(external_name)).index_set(externals_table, external_object);
+	}
+
+	var chunk = Self{
+		.externals = externals_table,
+		.name = name_symbol,
+		.opcodes = .{.allocator = env.allocator},
+		.constants = .{.allocator = env.allocator},
+		.lines = .{.allocator = env.allocator},
+		.bindings = &.{},
+		.arity = environment.argument_count,
+		.cursor = 0,
+	};
+
+	var compiler = Compiler{
+		.chunk = &chunk,
+		.env = env,
+	};
+
+	try compiler.compile_environment(environment);
+
+	return chunk;
+}
+
+pub const typeinfo = script.Typeinfo{
+	.name = "lambda",
+	.destruct = typeinfo_destruct,
+	.call = typeinfo_call,
+	.to_string = typeinfo_to_string,
+};
+
+fn typeinfo_call(context: script.Typeinfo.CallContext) script.Error!?*script.Object {
+	return @as(*Self, @ptrCast(@alignCast(context.userdata))).execute(context.env);
+}
+
+fn typeinfo_destruct(context: script.Typeinfo.DestructContext) void {
+	@as(*Self, @ptrCast(@alignCast(context.userdata))).deinit(context.env);
+}
+
+fn typeinfo_to_string(context: script.Typeinfo.ToStringContext) script.Error!*script.Object {
+	return (try (try context.env.push(@as(*Self, @ptrCast(@alignCast(context.userdata))).name)).to_string()).pop().?;
+}
+
+pub fn write(self: *Self, line: tokens.Line, opcode: Opcode) std.mem.Allocator.Error!void {
+	try self.opcodes.push(opcode);
+	try self.lines.push(line);
+}

src/coral/script/Table.zig

@@ -0,0 +1,135 @@
+const coral = @import("coral");
+
+const script = @import("../script.zig");
+
+associative: coral.map.Table(*script.Object, *script.Object, struct {
+	pub const hash = script.Object.hash;
+
+	pub const equals = script.Object.equals;
+}),
+
+contiguous: coral.Stack(?*script.Object),
+
+const Self = @This();
+
+pub fn deinit(self: *Self, env: *script.Runtime) void {
+	{
+		var entries = self.associative.entries();
+
+		while (entries.next()) |entry| {
+			env.release(entry.key);
+			env.release(entry.value);
+		}
+	}
+
+	self.associative.deinit();
+
+	while (self.contiguous.pop()) |value| {
+		if (value.*) |ref| {
+			env.release(ref);
+		}
+	}
+
+	self.contiguous.deinit();
+}
+
+pub fn init(env: *script.Runtime) Self {
+	return .{
+		.associative = .{
+			.allocator = env.allocator,
+			.traits = .{},
+		},
+
+		.contiguous = .{.allocator = env.allocator},
+	};
+}
+
+pub const typeinfo = script.Typeinfo{
+	.name = "table",
+	.destruct = typeinfo_destruct,
+	.get = typeinfo_get,
+	.set = typeinfo_set,
+	.count = typeinfo_count,
+};
+
+fn typeinfo_count(context: script.Typeinfo.CountContext) script.Error!script.Fixed {
+	const table = @as(*Self, @ptrCast(@alignCast(context.userdata)));
+
+	return @intCast(table.associative.len + table.contiguous.values.len);
+}
+
+fn typeinfo_destruct(context: script.Typeinfo.DestructContext) void {
+	@as(*Self, @ptrCast(@alignCast(context.userdata))).deinit(context.env);
+}
+
+fn typeinfo_get(context: script.Typeinfo.GetContext) script.Error!?*script.Object {
+	const table = @as(*Self, @ptrCast(@alignCast(context.userdata)));
+	const index = (try context.push_index()).pop().?;
+
+	defer context.env.release(index);
+
+	if (index.is_fixed()) |fixed| {
+		if (fixed < 0) {
+			// TODO: Negative indexing.
+			unreachable;
+		}
+
+		if (fixed < table.contiguous.values.len) {
+			return table.contiguous.values[@intCast(fixed)];
+		}
+	}
+
+	if (table.associative.lookup(index)) |value| {
+		return value;
+	}
+
+	return null;
+}
+
+fn typeinfo_set(context: script.Typeinfo.SetContext) script.Error!void {
+	const table = @as(*Self, @ptrCast(@alignCast(context.userdata)));
+	const index = (try context.push_index()).pop().?;
+
+	errdefer context.env.release(index);
+
+	if (index.is_fixed()) |fixed| {
+		if (fixed < 0) {
+			// TODO: Negative indexing.
+			unreachable;
+		}
+
+		if (fixed < table.contiguous.values.len) {
+			const maybe_replacing = &table.contiguous.values[@intCast(fixed)];
+
+			if (maybe_replacing.*) |replacing| {
+				context.env.release(replacing);
+			}
+
+			if ((try context.push_value()).pop()) |value| {
+				errdefer context.env.release(value);
+
+				maybe_replacing.* = value;
+			} else {
+				maybe_replacing.* = null;
+			}
+
+			return;
+		}
+	}
+
+	const value = (try context.push_value()).pop() orelse {
+		if (table.associative.remove(index)) |removed| {
+			context.env.release(removed.key);
+			context.env.release(removed.value);
+		}
+
+		return;
+	};
+
+	errdefer context.env.release(value);
+
+	if (try table.associative.replace(index, value)) |replaced| {
+		context.env.release(replaced.key);
+		context.env.release(replaced.value);
+	}
+}

src/coral/script/tokens.zig

@@ -0,0 +1,535 @@
+const coral = @import("coral");
+
+const std = @import("std");
+
+pub const Line = struct {
+	number: u32,
+};
+
+pub const Token = union(enum) {
+	end,
+	unknown: u8,
+	newline,
+	identifier: []const u8,
+	builtin: []const u8,
+
+	symbol_plus,
+	symbol_minus,
+	symbol_asterisk,
+	symbol_forward_slash,
+	symbol_paren_left,
+	symbol_paren_right,
+	symbol_bang,
+	symbol_comma,
+	symbol_at,
+	symbol_brace_left,
+	symbol_brace_right,
+	symbol_bracket_left,
+	symbol_bracket_right,
+	symbol_period,
+	symbol_colon,
+	symbol_less_than,
+	symbol_less_equals,
+	symbol_greater_than,
+	symbol_greater_equals,
+	symbol_equals,
+	symbol_double_equals,
+
+	number: []const u8,
+	string: []const u8,
+	template_string: []const u8,
+
+	keyword_nil,
+	keyword_false,
+	keyword_true,
+	keyword_return,
+	keyword_self,
+	keyword_const,
+	keyword_if,
+	keyword_do,
+	keyword_end,
+	keyword_while,
+	keyword_else,
+	keyword_elif,
+	keyword_var,
+	keyword_vec2,
+	keyword_vec3,
+	keyword_let,
+	keyword_lambda,
+
+	pub fn text(self: Token) []const u8 {
+		return switch (self) {
+			.end => "end",
+			.unknown => |unknown| @as([*]const u8, @ptrCast(&unknown))[0 .. 1],
+			.newline => "newline",
+
+			.identifier => |identifier| identifier,
+			.builtin => |identifier| identifier,
+
+			.symbol_plus => "+",
+			.symbol_minus => "-",
+			.symbol_asterisk => "*",
+			.symbol_forward_slash => "/",
+			.symbol_paren_left => "(",
+			.symbol_paren_right => ")",
+			.symbol_bang => "!",
+			.symbol_comma => ",",
+			.symbol_at => "@",
+			.symbol_brace_left => "{",
+			.symbol_brace_right => "}",
+			.symbol_bracket_left => "[",
+			.symbol_bracket_right => "]",
+			.symbol_period => ".",
+			.symbol_colon => ":",
+			.symbol_less_than => "<",
+			.symbol_less_equals => "<=",
+			.symbol_greater_than => ">",
+			.symbol_greater_equals => ">=",
+			.symbol_equals => "=",
+			.symbol_double_equals => "==",
+
+			.number => |literal| literal,
+			.string => |literal| literal,
+			.template_string => |literal| literal,
+
+			.keyword_const => "const",
+			.keyword_nil => "nil",
+			.keyword_false => "false",
+			.keyword_true => "true",
+			.keyword_return => "return",
+			.keyword_self => "self",
+			.keyword_if => "if",
+			.keyword_do => "do",
+			.keyword_end => "end",
+			.keyword_while => "while",
+			.keyword_elif => "elif",
+			.keyword_else => "else",
+			.keyword_var => "var",
+			.keyword_vec2 => "vec2",
+			.keyword_vec3 => "vec3",
+			.keyword_let => "let",
+			.keyword_lambda => "lambda",
+		};
+	}
+};
+
+pub const Stream = struct {
+	source: []const u8,
+	line: Line = .{.number = 1},
+	token: Token = .newline,
+
+	pub fn skip_newlines(self: *Stream) void {
+		self.step();
+
+		while (self.token == .newline) {
+			self.step();
+		}
+	}
+
+	pub fn step(self: *Stream) void {
+		var cursor = @as(usize, 0);
+
+		defer self.source = self.source[cursor ..];
+
+		while (cursor < self.source.len) {
+			switch (self.source[cursor]) {
+				'#' => {
+					cursor += 1;
+
+					while (cursor < self.source.len and self.source[cursor] != '\n') {
+						cursor += 1;
+					}
+				},
+
+				' ', '\t' => cursor += 1,
+
+				'\n' => {
+					cursor += 1;
+					self.token = .newline;
+					self.line.number += 1;
+
+					return;
+				},
+
+				'0' ... '9' => {
+					const begin = cursor;
+
+					cursor += 1;
+
+					while (cursor < self.source.len) switch (self.source[cursor]) {
+						'0' ... '9' => cursor += 1,
+
+						'.' => {
+							cursor += 1;
+
+							while (cursor < self.source.len) switch (self.source[cursor]) {
+								'0' ... '9' => cursor += 1,
+								else => break,
+							};
+
+							self.token = .{.number = self.source[begin .. cursor]};
+
+							return;
+						},
+
+						else => break,
+					};
+
+					self.token = .{.number = self.source[begin .. cursor]};
+
+					return;
+				},
+
+				'A' ... 'Z', 'a' ... 'z', '_' => {
+					const begin = cursor;
+
+					cursor += 1;
+
+					while (cursor < self.source.len) switch (self.source[cursor]) {
+						'0'...'9', 'A'...'Z', 'a'...'z', '_' => cursor += 1,
+						else => break,
+					};
+
+					const identifier = self.source[begin .. cursor];
+
+					std.debug.assert(identifier.len != 0);
+
+					switch (identifier[0]) {
+						'c' => {
+							if (coral.are_equal(identifier[1 ..], "onst")) {
+								self.token = .keyword_const;
+
+								return;
+							}
+						},
+
+						'd' => {
+							if (coral.are_equal(identifier[1 ..], "o")) {
+								self.token = .keyword_do;
+
+								return;
+							}
+						},
+
+						'e' => {
+							if (coral.are_equal(identifier[1 ..], "lse")) {
+								self.token = .keyword_else;
+
+								return;
+							}
+
+							if (coral.are_equal(identifier[1 ..], "lif")) {
+								self.token = .keyword_elif;
+
+								return;
+							}
+
+							if (coral.are_equal(identifier[1 ..], "nd")) {
+								self.token = .keyword_end;
+
+								return;
+							}
+						},
+
+						'f' => {
+							if (coral.are_equal(identifier[1 ..], "alse")) {
+								self.token = .keyword_false;
+
+								return;
+							}
+						},
+
+						'i' => {
+							if (coral.are_equal(identifier[1 ..], "f")) {
+								self.token = .keyword_if;
+
+								return;
+							}
+						},
+
+						'l' => {
+							if (coral.are_equal(identifier[1 ..], "ambda")) {
+								self.token = .keyword_lambda;
+
+								return;
+							}
+
+							if (coral.are_equal(identifier[1 ..], "et")) {
+								self.token = .keyword_let;
+
+								return;
+							}
+						},
+
+						'n' => {
+							if (coral.are_equal(identifier[1 ..], "il")) {
+								self.token = .keyword_nil;
+
+								return;
+							}
+						},
+
+						'r' => {
+							if (coral.are_equal(identifier[1 ..], "eturn")) {
+								self.token = .keyword_return;
+
+								return;
+							}
+						},
+
+						's' => {
+							if (coral.are_equal(identifier[1 ..], "elf")) {
+								self.token = .keyword_self;
+
+								return;
+							}
+						},
+
+						't' => {
+							if (coral.are_equal(identifier[1 ..], "rue")) {
+								self.token = .keyword_true;
+
+								return;
+							}
+						},
+
+						'v' => {
+							const rest = identifier[1 ..];
+
+							if (coral.are_equal(rest, "ar")) {
+								self.token = .keyword_var;
+
+								return;
+							}
+
+							if (coral.are_equal(rest, "vec2")) {
+								self.token = .keyword_vec2;
+
+								return;
+							}
+
+							if (coral.are_equal(rest, "vec3")) {
+								self.token = .keyword_vec3;
+
+								return;
+							}
+						},
+
+						'w' => {
+							if (coral.are_equal(identifier[1 ..], "hile")) {
+								self.token = .keyword_while;
+
+								return;
+							}
+						},
+
+						else => {},
+					}
+
+					self.token = .{.identifier = identifier};
+
+					return;
+				},
+
+				'`' => {
+					cursor += 1;
+
+					const begin = cursor;
+
+					while (cursor < self.source.len) switch (self.source[cursor]) {
+						'`' => break,
+						else => cursor += 1,
+					};
+
+					self.token = .{.template_string = self.source[begin .. cursor]};
+					cursor += 1;
+
+					return;
+				},
+
+				'"' => {
+					cursor += 1;
+
+					const begin = cursor;
+
+					while (cursor < self.source.len) switch (self.source[cursor]) {
+						'"' => break,
+						else => cursor += 1,
+					};
+
+					self.token = .{.string = self.source[begin .. cursor]};
+					cursor += 1;
+
+					return;
+				},
+
+				'{' => {
+					self.token = .symbol_brace_left;
+					cursor += 1;
+
+					return;
+				},
+
+				'}' => {
+					self.token = .symbol_brace_right;
+					cursor += 1;
+
+					return;
+				},
+
+				'[' => {
+					self.token = .symbol_bracket_left;
+					cursor += 1;
+
+					return;
+				},
+
+				']' => {
+					self.token = .symbol_bracket_right;
+					cursor += 1;
+
+					return;
+				},
+
+				',' => {
+					self.token = .symbol_comma;
+					cursor += 1;
+
+					return;
+				},
+
+				'!' => {
+					self.token = .symbol_bang;
+					cursor += 1;
+
+					return;
+				},
+
+				')' => {
+					self.token = .symbol_paren_right;
+					cursor += 1;
+
+					return;
+				},
+
+				'(' => {
+					self.token = .symbol_paren_left;
+					cursor += 1;
+
+					return;
+				},
+
+				'/' => {
+					self.token = .symbol_forward_slash;
+					cursor += 1;
+
+					return;
+				},
+
+				'*' => {
+					self.token = .symbol_asterisk;
+					cursor += 1;
+
+					return;
+				},
+
+				'-' => {
+					self.token = .symbol_minus;
+					cursor += 1;
+
+					return;
+				},
+
+				'+' => {
+					self.token = .symbol_plus;
+					cursor += 1;
+
+					return;
+				},
+
+				':' => {
+					self.token = .symbol_colon;
+					cursor += 1;
+
+					return;
+				},
+
+				'=' => {
+					cursor += 1;
+
+					if (cursor < self.source.len) {
+						switch (self.source[cursor]) {
+							'=' => {
+								cursor += 1;
+								self.token = .symbol_double_equals;
+
+								return;
+							},
+
+							else => {},
+						}
+					}
+
+					self.token = .symbol_equals;
+
+					return;
+				},
+
+				'<' => {
+					cursor += 1;
+
+					if (cursor < self.source.len and (self.source[cursor] == '=')) {
+						cursor += 1;
+						self.token = .symbol_less_equals;
+
+						return;
+					}
+
+					self.token = .symbol_less_than;
+
+					return;
+				},
+
+				'>' => {
+					cursor += 1;
+
+					if (cursor < self.source.len and (self.source[cursor] == '=')) {
+						cursor += 1;
+						self.token = .symbol_greater_equals;
+
+						return;
+					}
+
+					self.token = .symbol_greater_than;
+
+					return;
+				},
+
+				'.' => {
+					self.token = .symbol_period;
+					cursor += 1;
+
+					return;
+				},
+
+				'@' => {
+					self.token = .symbol_at;
+					cursor += 1;
+
+					return;
+				},
+
+				else => {
+					self.token = .{.unknown = self.source[cursor]};
+					cursor += 1;
+
+					return;
+				},
+			}
+		}
+
+		self.token = .end;
+
+		return;
+	}
+};

src/coral/script/tree.zig

@@ -0,0 +1,268 @@
+pub const Expr = @import("./tree/Expr.zig");
+
+pub const Stmt = @import("./tree/Stmt.zig");
+
+const coral = @import("coral");
+
+const std = @import("std");
+
+const script = @import("../script.zig");
+
+const tokens = @import("./tokens.zig");
+
+pub const Declaration = struct {
+	identifier: []const coral.Byte,
+
+	is: packed struct {
+		readonly: bool = false,
+		captured: bool = false,
+	} = .{},
+};
+
+pub const Environment = struct {
+	captures: [capture_max]Capture = [_]Capture{.{.declaration_index = 0}} ** capture_max,
+	capture_count: u8 = 0,
+	declarations: [declaration_max]Declaration = [_]Declaration{.{.identifier = ""}} ** declaration_max,
+	declaration_count: u8 = 0,
+	argument_count: u8 = 0,
+	statement: ?*const Stmt = null,
+	enclosing: ?*Environment = null,
+
+	pub const Capture = union (enum) {
+		declaration_index: u8,
+		capture_index: u8,
+	};
+
+	pub const DeclareError = std.mem.Allocator.Error || error {
+		DeclarationExists,
+	};
+
+	const capture_max = std.math.maxInt(u8);
+
+	const declaration_max = std.math.maxInt(u8);
+
+	pub fn create_enclosed(self: *Environment, root: *Root) std.mem.Allocator.Error!*Environment {
+		const environment = try root.arena.allocator().create(Environment);
+
+		environment.* = .{.enclosing = self};
+
+		return environment;
+	}
+
+	fn declare(self: *Environment, declaration: Declaration) DeclareError!*const Declaration {
+		if (self.declaration_count == self.declarations.len) {
+			return error.OutOfMemory;
+		}
+
+		{
+			var environment = self;
+
+			while (true) {
+				var remaining_count = environment.declaration_count;
+
+				while (remaining_count != 0) {
+					remaining_count -= 1;
+
+					if (coral.are_equal(environment.declarations[remaining_count].identifier, declaration.identifier)) {
+						return error.DeclarationExists;
+					}
+				}
+
+				environment = environment.enclosing orelse break;
+			}
+		}
+
+		const declaration_slot = &self.declarations[self.declaration_count];
+
+		declaration_slot.* = declaration;
+		self.declaration_count += 1;
+
+		return declaration_slot;
+	}
+
+	pub fn declare_argument(self: *Environment, identifier: []const u8) DeclareError!*const Declaration {
+		std.debug.assert(self.declaration_count <= self.argument_count);
+
+		defer self.argument_count += 1;
+
+		return self.declare(.{
+			.identifier = identifier,
+			.is = .{.readonly = true},
+		});
+	}
+
+	pub fn declare_constant(self: *Environment, identifier: []const u8) DeclareError!*const Declaration {
+		return self.declare(.{
+			.identifier = identifier,
+			.is = .{.readonly = true},
+		});
+	}
+
+	pub fn declare_variable(self: *Environment, identifier: []const u8) DeclareError!*const Declaration {
+		return self.declare(.{.identifier = identifier});
+	}
+
+	pub fn resolve_declaration(self: *Environment, identifier: []const u8) std.mem.Allocator.Error!?*const Declaration {
+		var environment = self;
+		var ancestry = @as(u32, 0);
+
+		while (true) : (ancestry += 1) {
+			var remaining_count = environment.declaration_count;
+
+			while (remaining_count != 0) {
+				remaining_count -= 1;
+
+				const declaration = &environment.declarations[remaining_count];
+
+				if (coral.are_equal(declaration.identifier, identifier)) {
+					if (ancestry != 0) {
+						declaration.is.captured = true;
+						environment = self;
+						ancestry -= 1;
+
+						while (ancestry != 0) : (ancestry -= 1) {
+							if (environment.capture_count == environment.captures.len) {
+								return error.OutOfMemory;
+							}
+
+							environment.captures[environment.capture_count] = .{
+								.capture_index = environment.enclosing.?.capture_count
+							};
+
+							environment.capture_count += 1;
+							environment = environment.enclosing.?;
+						}
+
+						environment.captures[environment.capture_count] = .{.declaration_index = remaining_count};
+						environment.capture_count += 1;
+					}
+
+					return declaration;
+				}
+			}
+
+			environment = environment.enclosing orelse return null;
+		}
+	}
+
+	pub fn get_captures(self: *const Environment) []const Capture {
+		return self.captures[0 .. self.capture_count];
+	}
+
+	pub fn get_declarations(self: *const Environment) []const Declaration {
+		return self.declarations[0 .. self.declaration_count];
+	}
+};
+
+pub fn NodeChain(comptime Value: type) type {
+	return struct {
+		head: ?*Value = null,
+		tail: ?*Value = null,
+
+		pub const Nodes = struct {
+			current: ?*const Value,
+
+			pub fn next(self: *Nodes) ?*const Value {
+				const current = self.current orelse return null;
+
+				defer self.current = current.next;
+
+				return current;
+			}
+		};
+
+		const Self = @This();
+
+		pub fn append(self: *Self, value: *Value) void {
+			if (self.tail) |node| {
+				node.next = value;
+				self.tail = value;
+			} else {
+				self.tail = value;
+				self.head = value;
+			}
+		}
+
+		pub fn nodes(self: *const Self) Nodes {
+			return .{.current = self.head};
+		}
+	};
+}
+
+pub const ParseError = std.mem.Allocator.Error || error {
+	BadSyntax,
+};
+
+pub const Root = struct {
+	arena: std.heap.ArenaAllocator,
+	environment: Environment,
+	error_messages: MessageList,
+
+	const MessageList = coral.Stack([]coral.Byte);
+
+	pub fn report_error(self: *Root, line: tokens.Line, comptime format: []const u8, args: anytype) ParseError {
+		const allocator = self.arena.allocator();
+		const message = try coral.utf8.alloc_formatted(allocator, format, args);
+
+		defer allocator.free(message);
+
+		try self.error_messages.push(try coral.utf8.alloc_formatted(allocator, "{line_number}: {message}", .{
+			.message = message,
+			.line_number = line.number,
+		}));
+
+		return error.BadSyntax;
+	}
+
+	pub fn report_declare_error(self: *Root, line: tokens.Line, identifier: []const u8, @"error": Environment.DeclareError) ParseError {
+		return switch (@"error") {
+			error.OutOfMemory => error.OutOfMemory,
+
+			error.DeclarationExists => self.report_error(line, "declaration `{identifier}` already exists", .{
+				.identifier = identifier,
+			}),
+		};
+	}
+
+	pub fn create_node(self: *Root, node: anytype) std.mem.Allocator.Error!*@TypeOf(node) {
+		const copy = try self.arena.allocator().create(@TypeOf(node));
+
+		copy.* = node;
+
+		return copy;
+	}
+
+	pub fn create_string(self: *Root, comptime format: []const u8, args: anytype) std.mem.Allocator.Error![]const u8 {
+		return coral.utf8.alloc_formatted(self.arena.allocator(), format, args);
+	}
+
+	pub fn deinit(self: *Root) void {
+		self.error_messages.deinit();
+		self.arena.deinit();
+	}
+
+	pub fn init(allocator: std.mem.Allocator) std.mem.Allocator.Error!Root {
+		return .{
+			.arena = std.heap.ArenaAllocator.init(allocator),
+			.error_messages = .{.allocator = allocator},
+			.environment = .{},
+		};
+	}
+
+	pub fn parse(self: *Root, stream: *tokens.Stream) ParseError!void {
+		stream.skip_newlines();
+
+		const first_statement = try Stmt.parse(self, stream, &self.environment);
+		var current_statement = first_statement;
+
+		while (stream.token != .end) {
+			const next_statement = try Stmt.parse(self, stream, &self.environment);
+
+			current_statement.next = next_statement;
+			current_statement = next_statement;
+		}
+
+		self.environment.statement = first_statement;
+	}
+};
+

src/coral/script/tree/Expr.zig

@@ -0,0 +1,906 @@
+const Stmt = @import("./Stmt.zig");
+
+const coral = @import("coral");
+
+const tokens = @import("../tokens.zig");
+
+const tree = @import("../tree.zig");
+
+const std = @import("std");
+
+next: ?*const Self = null,
+line: tokens.Line,
+kind: Kind,
+
+pub const BinaryOp = struct {
+	rhs_operand: *Self,
+	lhs_operand: *Self,
+	operation: Operation,
+
+	pub const Operation = enum {
+		addition,
+		subtraction,
+		multiplication,
+		divsion,
+		equals_comparison,
+		greater_than_comparison,
+		greater_equals_comparison,
+		less_than_comparison,
+		less_equals_comparison,
+	};
+
+	fn parser(comptime parse_next: Parser, comptime operations: []const BinaryOp.Operation) Parser {
+		const BinaryOpParser = struct {
+			fn parse(root: *tree.Root, stream: *tokens.Stream, environment: *tree.Environment) tree.ParseError!*Self {
+				var expression = try parse_next(root, stream, environment);
+
+				inline for (operations) |operation| {
+					const token = comptime @as(tokens.Token, switch (operation) {
+						.addition => .symbol_plus,
+						.subtraction => .symbol_minus,
+						.multiplication => .symbol_asterisk,
+						.divsion => .symbol_forward_slash,
+						.equals_comparison => .symbol_double_equals,
+						.greater_than_comparison => .symbol_greater_than,
+						.greater_equals_comparison => .symbol_greater_equals,
+						.less_than_comparison => .symbol_less_than,
+						.less_equals_comparison => .symbol_less_equals,
+					});
+
+					if (stream.token == std.meta.activeTag(token)) {
+						stream.step();
+
+						if (stream.token == .end) {
+							return root.report_error(stream.line, "expected other half of expression after `" ++ comptime token.text() ++ "`", .{});
+						}
+
+						// TODO: Remove once Zig has fixed struct self-reassignment.
+						const unnecessary_temp = expression;
+
+						expression = try root.create_node(Self{
+							.line = stream.line,
+
+							.kind = .{
+								.binary_op = .{
+									.rhs_operand = try parse_next(root, stream, environment),
+									.operation = operation,
+									.lhs_operand = unnecessary_temp,
+								},
+							},
+						});
+					}
+				}
+
+				return expression;
+			}
+		};
+
+		return BinaryOpParser.parse;
+	}
+};
+
+pub const DeclarationGet = struct {
+	declaration: *const tree.Declaration,
+};
+
+pub const DeclarationSet = struct {
+	declaration: *const tree.Declaration,
+	assign: *const Self,
+};
+
+pub const FieldGet = struct {
+	identifier: []const coral.Byte,
+	object: *const Self,
+};
+
+pub const FieldSet = struct {
+	identifier: []const coral.Byte,
+	object: *const Self,
+	assign: *const Self,
+};
+
+pub const Invoke = struct {
+	argument: ?*const Self,
+	object: *const Self,
+};
+
+const Kind = union (enum) {
+	nil_literal,
+	true_literal,
+	false_literal,
+	number_literal: []const u8,
+	string_literal: []const u8,
+	string_template,
+	symbol_literal: []const u8,
+	vector2: Vector2,
+	vector3: Vector3,
+	table: tree.NodeChain(TableEntry),
+	group: *Self,
+	lambda_construct: LambdaConstruct,
+	declaration_get: DeclarationGet,
+	declaration_set: DeclarationSet,
+	field_get: FieldGet,
+	field_set: FieldSet,
+	external_get: ExternalGet,
+	subscript_get: SubscriptGet,
+	subscript_set: SubscriptSet,
+	binary_op: BinaryOp,
+	unary_op: UnaryOp,
+	invoke: Invoke,
+};
+
+pub const LambdaConstruct = struct {
+	environment: *const tree.Environment,
+};
+
+const Parser = fn (root: *tree.Root, stream: *tokens.Stream, environment: *tree.Environment) tree.ParseError!*Self;
+
+const ExternalGet = struct {
+	name: []const u8,
+};
+
+const Self = @This();
+
+pub const SubscriptGet = struct {
+	index: *const Self,
+	object: *const Self,
+};
+
+pub const SubscriptSet = struct {
+	index: *const Self,
+	object: *const Self,
+	assign: *const Self,
+};
+
+pub const TableEntry = struct {
+	next: ?*const TableEntry = null,
+	key: *const Self,
+	value: *const Self,
+};
+
+const TemplateToken = union (enum) {
+	invalid: []const coral.Byte,
+	literal: []const coral.Byte,
+	expression: []const coral.Byte,
+
+	fn extract(source: *[]const coral.Byte) ?TemplateToken {
+		var cursor = @as(usize, 0);
+
+		defer source.* = source.*[cursor ..];
+
+		while (cursor < source.len) {
+			switch (source.*[cursor]) {
+				'{' => {
+					cursor += 1;
+
+					while (true) : (cursor += 1) {
+						if (cursor == source.len) {
+							return .{.invalid = source.*[0 .. cursor]};
+						}
+
+						if (source.*[cursor] == '}') {
+							const token = TemplateToken{.expression = source.*[1 .. cursor]};
+
+							cursor += 1;
+
+							return token;
+						}
+					}
+				},
+
+				else => {
+					cursor += 1;
+
+					while (true) : (cursor += 1) {
+						if (cursor == source.len) {
+							return .{.literal = source.*[0 .. cursor]};
+						}
+
+						if (source.*[cursor] == '{') {
+							const cursor_next = cursor + 1;
+
+							if (cursor_next == source.len) {
+								return .{.invalid = source.*[0 .. cursor]};
+							}
+
+							if (source.*[cursor_next] == '{') {
+								cursor = cursor_next;
+
+								return .{.literal = source.*[0 .. cursor]};
+							}
+
+							return .{.literal = source.*[0 .. cursor]};
+						}
+					}
+				}
+			}
+		}
+
+		return null;
+	}
+};
+
+pub const UnaryOp = struct {
+	operand: *Self,
+	operation: Operation,
+
+	pub const Operation = enum {
+		numeric_negation,
+		boolean_negation,
+	};
+};
+
+pub const Vector2 = struct {
+	x: *const Self,
+	y: *const Self,
+};
+
+pub const Vector3 = struct {
+	x: *const Self,
+	y: *const Self,
+	z: *const Self,
+};
+
+pub fn parse(root: *tree.Root, stream: *tokens.Stream, environment: *tree.Environment) tree.ParseError!*Self {
+	const expression = try parse_additive(root, stream, environment);
+
+	if (stream.token == .symbol_equals) {
+		stream.skip_newlines();
+
+		if (stream.token == .end) {
+			return root.report_error(stream.line, "expected assignment after `=`", .{});
+		}
+
+		return root.create_node(Self{
+			.line = stream.line,
+
+			.kind = switch (expression.kind) {
+				.declaration_get => |declaration_get| convert: {
+					if (declaration_get.declaration.is.readonly) {
+						return root.report_error(stream.line, "readonly declarations cannot be re-assigned", .{});
+					}
+
+					break: convert .{
+						.declaration_set = .{
+							.assign = try parse(root, stream, environment),
+							.declaration = declaration_get.declaration,
+						},
+					};
+				},
+
+				.field_get => |field_get| .{
+					.field_set = .{
+						.assign = try parse(root, stream, environment),
+						.object = field_get.object,
+						.identifier = field_get.identifier,
+					},
+				},
+
+				.subscript_get => |subscript_get| .{
+					.subscript_set = .{
+						.assign = try parse(root, stream, environment),
+						.object = subscript_get.object,
+						.index = subscript_get.index,
+					},
+				},
+
+				else => return root.report_error(stream.line, "expected local or field on left-hand side of expression", .{}),
+			},
+		});
+	}
+
+	return expression;
+}
+
+const parse_additive = BinaryOp.parser(parse_equality, &.{
+	.addition,
+	.subtraction,
+});
+
+const parse_comparison = BinaryOp.parser(parse_term, &.{
+	.greater_than_comparison,
+	.greater_equals_comparison,
+	.less_than_comparison,
+	.less_equals_comparison
+});
+
+const parse_equality = BinaryOp.parser(parse_comparison, &.{
+	.equals_comparison,
+});
+
+fn parse_factor(root: *tree.Root, stream: *tokens.Stream, environment: *tree.Environment) tree.ParseError!*Self {
+	var expression = try parse_operand(root, stream, environment);
+
+	while (true) {
+		switch (stream.token) {
+			.symbol_period => {
+				stream.skip_newlines();
+
+				// TODO: Remove when Zig fixes miscompilation with in-place struct re-assignment.
+				const unnecessary_temp = expression;
+
+				expression = try root.create_node(Self{
+					.line = stream.line,
+
+					.kind = .{
+						.field_get = .{
+							.identifier = switch (stream.token) {
+								.identifier => |field_identifier| field_identifier,
+								else => return root.report_error(stream.line, "expected identifier after `.`", .{}),
+							},
+
+							.object = unnecessary_temp,
+						},
+					},
+				});
+
+				stream.skip_newlines();
+			},
+
+			.symbol_bracket_left => {
+				stream.skip_newlines();
+
+				// TODO: Remove when Zig fixes miscompilation with in-place struct re-assignment.
+				const unnecessary_temp = expression;
+
+				expression = try root.create_node(Self{
+					.line = stream.line,
+
+					.kind = .{
+						.subscript_get = .{
+							.index = try parse(root, stream, environment),
+							.object = unnecessary_temp,
+						},
+					},
+				});
+
+				if (stream.token != .symbol_bracket_right) {
+					return root.report_error(stream.line, "expected closing `]` on subscript", .{});
+				}
+
+				stream.skip_newlines();
+			},
+
+			.symbol_paren_left => {
+				const lines_stepped = stream.line;
+
+				stream.skip_newlines();
+
+				var first_argument = @as(?*Self, null);
+
+				if (stream.token != .symbol_paren_right) {
+					var argument = try parse(root, stream, environment);
+
+					first_argument = argument;
+
+					while (true) {
+						switch (stream.token) {
+							.symbol_comma => stream.skip_newlines(),
+							.symbol_paren_right => break,
+							else => return root.report_error(stream.line, "expected `,` or `)` after lambda argument", .{}),
+						}
+
+						const next_argument = try parse(root, stream, environment);
+
+						argument.next = next_argument;
+						argument = next_argument;
+					}
+				}
+
+				stream.skip_newlines();
+
+				// TODO: Remove when Zig fixes miscompilation with in-place struct re-assignment.
+				const unnecessary_temp = expression;
+
+				expression = try root.create_node(Self{
+					.line = lines_stepped,
+
+					.kind = .{
+						.invoke = .{
+							.argument = first_argument,
+							.object = unnecessary_temp,
+						},
+					},
+				});
+			},
+
+			else => break,
+		}
+	}
+
+	return expression;
+}
+
+fn parse_operand(root: *tree.Root, stream: *tokens.Stream, environment: *tree.Environment) tree.ParseError!*Self {
+	switch (stream.token) {
+		.symbol_paren_left => {
+			stream.skip_newlines();
+
+			const expression = try parse(root, stream, environment);
+
+			if (stream.token != .symbol_paren_right) {
+				return root.report_error(stream.line, "expected a closing `)` after expression", .{});
+			}
+
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+				.kind = .{.group = expression},
+			});
+		},
+
+		.keyword_nil => {
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+				.kind = .nil_literal,
+			});
+		},
+
+		.keyword_true => {
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+				.kind = .true_literal,
+			});
+		},
+
+		.keyword_false => {
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+				.kind = .false_literal,
+			});
+		},
+
+		.keyword_vec2 => {
+			stream.skip_newlines();
+
+			if (stream.token != .symbol_paren_left) {
+				return root.report_error(stream.line, "expected an opening `(` after `vec2`", .{});
+			}
+
+			stream.skip_newlines();
+
+			const x_expression = try parse(root, stream, environment);
+
+			switch (stream.token) {
+				.symbol_paren_right => {
+					stream.skip_newlines();
+
+					return root.create_node(Self{
+						.line = stream.line,
+
+						.kind = .{
+							.vector2 = .{
+								.x = x_expression,
+								.y = x_expression,
+							},
+						},
+					});
+				},
+
+				.symbol_comma => {
+					stream.skip_newlines();
+
+					const y_expression = try parse(root, stream, environment);
+
+					stream.skip_newlines();
+
+					if (stream.token != .symbol_paren_right) {
+						return root.report_error(stream.line, "expected a closing `)` after `vec3`", .{});
+					}
+
+					return root.create_node(Self{
+						.line = stream.line,
+
+						.kind = .{
+							.vector2 = .{
+								.x = x_expression,
+								.y = y_expression,
+							},
+						},
+					});
+				},
+
+				else => return root.report_error(stream.line, "expected a closing `)` after `vec3`", .{}),
+			}
+		},
+
+		.keyword_vec3 => {
+			stream.skip_newlines();
+
+			if (stream.token != .symbol_paren_left) {
+				return root.report_error(stream.line, "expected an opening `(` after `vec2`", .{});
+			}
+
+			stream.skip_newlines();
+
+			const x_expression = try parse(root, stream, environment);
+
+			switch (stream.token) {
+				.symbol_paren_right => {
+					stream.skip_newlines();
+
+					return root.create_node(Self{
+						.line = stream.line,
+
+						.kind = .{
+							.vector3 = .{
+								.x = x_expression,
+								.y = x_expression,
+								.z = x_expression,
+							},
+						},
+					});
+				},
+
+				.symbol_comma => {
+					stream.skip_newlines();
+
+					const y_expression = try parse(root, stream, environment);
+
+					stream.skip_newlines();
+
+					const z_expression = try parse(root, stream, environment);
+
+					stream.skip_newlines();
+
+					if (stream.token != .symbol_paren_right) {
+						return root.report_error(stream.line, "expected a closing `)` after `vec3`", .{});
+					}
+
+					return root.create_node(Self{
+						.line = stream.line,
+
+						.kind = .{
+							.vector3 = .{
+								.x = x_expression,
+								.y = y_expression,
+								.z = z_expression,
+							},
+						},
+					});
+				},
+
+				else => return root.report_error(stream.line, "expected a closing `)` after `vec3`", .{}),
+			}
+		},
+
+		.number => |value| {
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+				.kind = .{.number_literal = value},
+			});
+		},
+
+		.string => |value| {
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+				.kind = .{.string_literal = value},
+			});
+		},
+
+		.template_string => |value| {
+			const line = stream.line;
+
+			stream.skip_newlines();
+
+			return parse_template(root, value, line, environment);
+		},
+
+		.symbol_at => {
+			stream.step();
+
+			const identifier = switch (stream.token) {
+				.identifier => |identifier| identifier,
+				else => return root.report_error(stream.line, "expected identifier after `@`", .{}),
+			};
+
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+				.kind = .{.external_get = .{.name = identifier}},
+			});
+		},
+
+		.symbol_period => {
+			stream.step();
+
+			const identifier = switch (stream.token) {
+				.identifier => |identifier| identifier,
+				else => return root.report_error(stream.line, "expected identifier after `.`", .{}),
+			};
+
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+				.kind = .{.symbol_literal = identifier},
+			});
+		},
+
+		.identifier => |identifier| {
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+
+				.kind = .{
+					.declaration_get = .{
+						.declaration = (try environment.resolve_declaration(identifier)) orelse {
+							return root.report_error(stream.line, "undefined identifier `{identifier}`", .{
+								.identifier = identifier,
+							});
+						}
+					},
+				},
+			});
+		},
+
+		.keyword_lambda => {
+			stream.skip_newlines();
+
+			if (stream.token != .symbol_paren_left) {
+				return root.report_error(stream.line, "expected `(` after opening lambda block", .{});
+			}
+
+			stream.skip_newlines();
+
+			var lambda_environment = try environment.create_enclosed(root);
+
+			while (stream.token != .symbol_paren_right) {
+				const identifier = switch (stream.token) {
+					.identifier => |identifier| identifier,
+					else => return root.report_error(stream.line, "expected identifier", .{}),
+				};
+
+				_ = lambda_environment.declare_argument(identifier) catch |declare_error| {
+					return root.report_declare_error(stream.line, identifier, declare_error);
+				};
+
+				stream.skip_newlines();
+
+				switch (stream.token) {
+					.symbol_comma => stream.skip_newlines(),
+					.symbol_paren_right => break,
+					else => return root.report_error(stream.line, "expected `,` or `)` after identifier", .{}),
+				}
+			}
+
+			stream.skip_newlines();
+
+			if (stream.token != .symbol_colon) {
+				return root.report_error(stream.line, "expected `:` after closing `)` of lambda identifiers", .{});
+			}
+
+			stream.skip_newlines();
+
+			if (stream.token != .keyword_end) {
+				const first_statement = try Stmt.parse(root, stream, lambda_environment);
+				var current_statement = first_statement;
+
+				while (stream.token != .keyword_end) {
+					const next_statement = try Stmt.parse(root, stream, lambda_environment);
+
+					current_statement.next = next_statement;
+					current_statement = next_statement;
+				}
+
+				lambda_environment.statement = first_statement;
+			}
+
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+				.kind = .{.lambda_construct = .{.environment = lambda_environment}},
+			});
+		},
+
+		.symbol_brace_left => {
+			stream.skip_newlines();
+
+			return parse_table(root, stream, environment);
+		},
+
+		.symbol_minus => {
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+
+				.kind = .{
+					.unary_op = .{
+						.operand = try parse_factor(root, stream, environment),
+						.operation = .numeric_negation,
+					},
+				},
+			});
+		},
+
+		.symbol_bang => {
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+
+				.kind = .{
+					.unary_op = .{
+						.operand = try parse_factor(root, stream, environment),
+						.operation = .boolean_negation,
+					},
+				},
+			});
+		},
+
+		else => return root.report_error(stream.line, "unexpected token in expression", .{}),
+	}
+}
+
+fn parse_table(root: *tree.Root, stream: *tokens.Stream, environment: *tree.Environment) tree.ParseError!*Self {
+	var entries = tree.NodeChain(TableEntry){};
+	var sequential_index = @as(usize, 0);
+
+	while (true) {
+		switch (stream.token) {
+			.symbol_brace_right => {
+				stream.skip_newlines();
+
+				return root.create_node(Self{
+					.line = stream.line,
+					.kind = .{.table = entries},
+				});
+			},
+
+			.symbol_bracket_left => {
+				stream.skip_newlines();
+
+				const key = try parse(root, stream, environment);
+
+				if (stream.token != .symbol_bracket_right)  {
+					return root.report_error(stream.line, "expected `]` after subscript index expression", .{});
+				}
+
+				stream.skip_newlines();
+
+				if (stream.token != .symbol_equals) {
+					return root.report_error(stream.line, "expected `=` after table expression key", .{});
+				}
+
+				stream.skip_newlines();
+
+				entries.append(try root.create_node(TableEntry{
+					.value = try parse(root, stream, environment),
+					.key = key,
+				}));
+			},
+
+			.symbol_period => {
+				stream.step();
+
+				const field = switch (stream.token) {
+					.identifier => |identifier| identifier,
+					else => return root.report_error(stream.line, "invalid symbol literal", .{}),
+				};
+
+				stream.skip_newlines();
+
+				switch (stream.token) {
+					.symbol_comma => {
+						stream.skip_newlines();
+
+						entries.append(try root.create_node(TableEntry{
+							.key = try root.create_node(Self{
+								.line = stream.line,
+								.kind = .{.number_literal = try root.create_string("{i}", .{.i = sequential_index})},
+							}),
+
+							.value = try root.create_node(Self{
+								.line = stream.line,
+								.kind = .{.symbol_literal = field},
+							}),
+						}));
+
+						sequential_index += 1;
+					},
+
+					.symbol_equals => {
+						stream.skip_newlines();
+
+						entries.append(try root.create_node(TableEntry{
+							.value = try parse(root, stream, environment),
+
+							.key = try root.create_node(Self{
+								.line = stream.line,
+								.kind = .{.symbol_literal = field},
+							}),
+						}));
+					},
+
+					else => return root.report_error(stream.line, "expected `,` or `=` after symbol", .{}),
+				}
+			},
+
+			else => {
+				entries.append(try root.create_node(TableEntry{
+					.value = try parse(root, stream, environment),
+
+					.key = try root.create_node(Self{
+						.line = stream.line,
+						.kind = .{.number_literal = try root.create_string("{i}", .{.i = sequential_index})},
+					}),
+				}));
+
+				sequential_index += 1;
+			},
+		}
+
+		switch (stream.token) {
+			.symbol_brace_right => {
+				stream.skip_newlines();
+
+				return root.create_node(Self{
+					.line = stream.line,
+					.kind = .{.table = entries},
+				});
+			},
+
+			.symbol_comma => stream.skip_newlines(),
+			else => return root.report_error(stream.line, "expected `,` or '}' after table key value pair", .{}),
+		}
+	}
+}
+
+fn parse_template(root: *tree.Root, template: []const coral.Byte, line: tokens.Line, environment: *tree.Environment) tree.ParseError!*Self {
+	const expression_head = try root.create_node(Self{
+		.line = line,
+		.kind = .string_template,
+	});
+
+	var expression_tail = expression_head;
+	var source = template;
+
+	while (TemplateToken.extract(&source)) |token| {
+		const expression = try switch (token) {
+			.invalid => |invalid| root.report_error(line, "invalid template format: `{invalid}`", .{
+				.invalid = invalid,
+			}),
+
+			.literal => |literal| root.create_node(Self{
+				.line = line,
+				.kind = .{.string_literal = literal},
+			}),
+
+			.expression => |expression| create: {
+				var stream = tokens.Stream{
+					.source = expression,
+					.line = line,
+				};
+
+				stream.step();
+
+				break: create try parse(root, &stream, environment);
+			},
+		};
+
+		expression_tail.next = expression;
+		expression_tail = expression;
+	}
+
+	return expression_head;
+}
+
+const parse_term = BinaryOp.parser(parse_factor, &.{
+	.multiplication,
+	.divsion,
+});

src/coral/script/tree/Stmt.zig

@@ -0,0 +1,242 @@
+const Expr = @import("./Expr.zig");
+
+const coral = @import("coral");
+
+const tokens = @import("../tokens.zig");
+
+const tree = @import("../tree.zig");
+
+next: ?*const Self = null,
+line: tokens.Line,
+
+kind: union (enum) {
+	top_expression: *const Expr,
+	@"return": Return,
+	declare: Declare,
+	@"if": If,
+	@"while": While,
+},
+
+pub const Declare = struct {
+	declaration: *const tree.Declaration,
+	initial_expression: *const Expr,
+};
+
+pub const If = struct {
+	then_expression: *const Expr,
+	@"then": *const Self,
+	@"else": ?*const Self,
+};
+
+pub const Return = struct {
+	returned_expression: ?*const Expr,
+};
+
+const Self = @This();
+
+pub const While = struct {
+	loop_expression: *const Expr,
+	loop: *const Self,
+};
+
+pub fn parse(root: *tree.Root, stream: *tokens.Stream, environment: *tree.Environment) tree.ParseError!*Self {
+	switch (stream.token) {
+		.keyword_return => {
+			stream.step();
+
+			if (stream.token != .end and stream.token != .newline) {
+				return root.create_node(Self{
+					.line = stream.line,
+					.kind = .{.@"return" = .{.returned_expression = try Expr.parse(root, stream, environment)}},
+				});
+			}
+
+			if (stream.token != .end and stream.token != .newline) {
+				return root.report_error(stream.line, "expected end or newline after return statement", .{});
+			}
+
+			return root.create_node(Self{
+				.line = stream.line,
+				.kind = .{.@"return" = .{.returned_expression = null}},
+			});
+		},
+
+		.keyword_while => {
+			defer stream.skip_newlines();
+
+			stream.step();
+
+			const condition_expression = try Expr.parse(root, stream, environment);
+
+			if (stream.token != .symbol_colon) {
+				return root.report_error(stream.line, "expected `:` after `while` statement", .{});
+			}
+
+			stream.skip_newlines();
+
+			const first_statement = try parse(root, stream, environment);
+
+			{
+				var current_statement = first_statement;
+
+				while (stream.token != .keyword_end) {
+					const next_statement = try parse(root, stream, environment);
+
+					current_statement.next = next_statement;
+					current_statement = next_statement;
+				}
+			}
+
+			return root.create_node(Self{
+				.line = stream.line,
+
+				.kind = .{
+					.@"while" = .{
+						.loop = first_statement,
+						.loop_expression = condition_expression,
+					},
+				},
+			});
+		},
+
+		.keyword_var, .keyword_let => {
+			const is_constant = stream.token == .keyword_let;
+
+			stream.skip_newlines();
+
+			const identifier = switch (stream.token) {
+				.identifier => |identifier| identifier,
+				else => return root.report_error(stream.line, "expected identifier after declaration", .{}),
+			};
+
+			stream.skip_newlines();
+
+			if (stream.token != .symbol_equals) {
+				return root.report_error(stream.line, "expected `=` after declaration `{identifier}`", .{
+					.identifier = identifier,
+				});
+			}
+
+			stream.skip_newlines();
+
+			return root.create_node(Self{
+				.line = stream.line,
+
+				.kind = .{
+					.declare = .{
+						.initial_expression = try Expr.parse(root, stream, environment),
+
+						.declaration = declare: {
+							if (is_constant) {
+								break: declare environment.declare_constant(identifier) catch |declaration_error| {
+									return root.report_declare_error(stream.line, identifier, declaration_error);
+								};
+							}
+
+							break: declare environment.declare_variable(identifier) catch |declaration_error| {
+								return root.report_declare_error(stream.line, identifier, declaration_error);
+							};
+						},
+					},
+				},
+			});
+		},
+
+		.keyword_if => return parse_branch(root, stream, environment),
+
+		else => return root.create_node(Self{
+			.line = stream.line,
+			.kind = .{.top_expression = try Expr.parse(root, stream, environment)},
+		}),
+	}
+}
+
+fn parse_branch(root: *tree.Root, stream: *tokens.Stream, environment: *tree.Environment) tree.ParseError!*Self {
+	stream.step();
+
+	const expression = try Expr.parse(root, stream, environment);
+
+	if (stream.token != .symbol_colon) {
+		return root.report_error(stream.line, "expected `:` after `{token}`", .{.token = stream.token.text()});
+	}
+
+	stream.skip_newlines();
+
+	const first_then_statement = try parse(root, stream, environment);
+	var current_then_statement = first_then_statement;
+
+	while (true) {
+		switch (stream.token) {
+			.keyword_end => {
+				stream.skip_newlines();
+
+				return root.create_node(Self{
+					.line = stream.line,
+
+					.kind = .{
+						.@"if" = .{
+							.then_expression = expression,
+							.@"then" = first_then_statement,
+							.@"else" = null,
+						},
+					},
+				});
+			},
+
+			.keyword_else => {
+				stream.step();
+
+				if (stream.token != .symbol_colon) {
+					return root.report_error(stream.line, "expected `:` after `if` statement condition", .{});
+				}
+
+				stream.skip_newlines();
+
+				const first_else_statement = try parse(root, stream, environment);
+				var current_else_statement = first_else_statement;
+
+				while (stream.token != .keyword_end) {
+					const next_statement = try parse(root, stream, environment);
+
+					current_else_statement.next = next_statement;
+					current_else_statement = next_statement;
+				}
+
+				stream.skip_newlines();
+
+				return root.create_node(Self{
+					.line = stream.line,
+
+					.kind = .{
+						.@"if" = .{
+							.@"else" = first_else_statement,
+							.@"then" = first_then_statement,
+							.then_expression = expression,
+						},
+					}
+				});
+			},
+
+			.keyword_elif => {
+				return root.create_node(Self{
+					.line = stream.line,
+
+					.kind = .{
+						.@"if" = .{
+							.@"else" = try parse_branch(root, stream, environment),
+							.@"then" = first_then_statement,
+							.then_expression = expression,
+						},
+					},
+				});
+			},
+
+			else => {
+				const next_statement = try parse(root, stream, environment);
+
+				current_then_statement.next = next_statement;
+				current_then_statement = next_statement;
+			},
+		}
+	}
+}