Add support for basic lambda syntax

debug/app.ona

@@ -1,18 +1,22 @@
 
 var i = 0
 
+let pr = lambda ():
+	@print("foo")
+end
+
 while i < 5:
-	@print("hello, world")
+	pr("hello, world")
 
 	i = i + 1
 end
 
 if i > 6:
-	@print("`i` greater than `6`")
+	pr("`i` greater than `6`")
 elif i == 4:
-	@print("`i` is equal to `4`")
+	pr("`i` is equal to `4`")
 else:
-	@print("i'unno")
+	pr("i'unno")
 end
 
 return {

source/ona/kym.zig

@@ -33,6 +33,7 @@ pub const RuntimeEnv = struct {
 			float: Float,
 			string: []const coral.io.Byte,
 			symbol: []const coral.io.Byte,
+			chunk: Chunk,
 		};
 
 		const Opcode = union (enum) {
@@ -124,17 +125,35 @@ pub const RuntimeEnv = struct {
 						});
 					},
 
-					.table_literal => |fields| {
+					.table_literal => |literal| {
-						if (fields.values.len > coral.math.max_int(@typeInfo(u32).Int)) {
+						if (literal.values.len > coral.math.max_int(@typeInfo(u32).Int)) {
 							return error.OutOfMemory;
 						}
 
-						for (fields.values) |field| {
+						for (literal.values) |field| {
 							try self.compile_expression(chunk, field.value_expression);
 							try self.compile_expression(chunk, field.key_expression);
 						}
 
-						try chunk.opcodes.push_one(.{.push_table = @intCast(fields.values.len)});
+						try chunk.opcodes.push_one(.{.push_table = @intCast(literal.values.len)});
+					},
+
+					.lambda_literal => |literal| {
+						if (literal.argument_identifiers.values.len > coral.math.max_int(@typeInfo(u32).Int)) {
+							return error.OutOfMemory;
+						}
+
+						var lambda_chunk = try Chunk.make(chunk.env, "<lambda>");
+
+						errdefer lambda_chunk.free();
+
+						try lambda_chunk.compile(literal.block_statements.values);
+
+						try chunk.opcodes.push_one(.{
+							.push_const = try chunk.declare_constant(.{
+								.chunk = lambda_chunk,
+							}),
+						});
 					},
 
 					.binary_operation => |operation| {
@@ -374,9 +393,18 @@ pub const RuntimeEnv = struct {
 
 		fn compile(self: *Chunk, statements: []const ast.Statement) RuntimeError!void {
 			var unit = CompilationUnit{};
+			var has_returned = false;
 
 			for (statements) |statement| {
 				try unit.compile_statement(self, statement);
+
+				if (statement == .@"return") {
+					has_returned = true;
+				}
+			}
+
+			if (!has_returned) {
+				try self.opcodes.push_one(.push_nil);
 			}
 		}
 
@@ -385,27 +413,27 @@ pub const RuntimeEnv = struct {
 				return self.env.raise(error.BadSyntax, "chunks cannot contain more than 65,535 constants");
 			}
 
-			const constant_index = self.constants.values.len;
+			const constant_object = try switch (constant) {
-
-			try self.constants.push_one(try switch (constant) {
 				.fixed => |fixed| self.env.new_fixed(fixed),
 				.float => |float| self.env.new_float(float),
 				.string => |string| self.env.new_string(string),
 				.symbol => |symbol| self.env.new_symbol(symbol),
-			});
 
-			return @intCast(constant_index);
+				.chunk => |chunk| self.env.new_dynamic(coral.io.bytes_of(&chunk).ptr, &.{
+					.size = @sizeOf(Chunk),
+					.name = "lambda",
+					.destruct = typeinfo_destruct,
+					.call = typeinfo_call,
+				}),
+			};
+
+			errdefer self.env.discard(constant_object);
+			try self.constants.push_one(constant_object);
+
+			return @intCast(self.constants.values.len - 1);
 		}
 
 		fn execute(self: *Chunk) RuntimeError!?*RuntimeRef {
-			try self.env.frames.push_one(.{
-				.arg_count = 0,
-				.locals_top = self.env.locals.values.len,
-				.name = self.name,
-			});
-
-			defer coral.debug.assert(self.env.frames.pop() != null);
-
 			var opcode_cursor = @as(u32, 0);
 
 			while (opcode_cursor < self.opcodes.values.len) : (opcode_cursor += 1) {
@@ -547,14 +575,16 @@ pub const RuntimeEnv = struct {
 							defer self.env.discard(callable);
 
 							try self.env.frames.push_one(.{
-								.name = "<lambda>",
+								.name = "<chunk>",
 								.arg_count = object_call,
 								.locals_top = self.env.locals.values.len,
 							});
 
 							defer coral.debug.assert(self.env.frames.pop() != null);
 
-							break: call try switch (callable.object().payload) {
+							const payload = callable.object().payload;
+
+							break: call try switch (payload) {
 								.syscall => |syscall| syscall(self.env),
 
 								.dynamic => |dynamic| dynamic.typeinfo().call(.{
@@ -566,18 +596,18 @@ pub const RuntimeEnv = struct {
 							};
 						};
 
-						for (0 .. object_call) |_| {
-							if (try self.pop_local()) |popped_arg| {
-								self.env.discard(popped_arg);
-							}
-						}
-
 						errdefer {
 							if (result) |ref| {
 								self.env.discard(ref);
 							}
 						}
 
+						for (0 .. object_call) |_| {
+							if (try self.pop_local()) |popped_arg| {
+								self.env.discard(popped_arg);
+							}
+						}
+
 						try self.env.locals.push_one(result);
 					},
 
@@ -934,6 +964,14 @@ pub const RuntimeEnv = struct {
 		fn pop_local(self: *Chunk) RuntimeError!?*RuntimeRef {
 			return self.env.locals.pop() orelse self.env.raise(error.IllegalState, "stack underflow");
 		}
+
+		fn typeinfo_call(method: Typeinfo.Method) RuntimeError!?*RuntimeRef {
+			return @as(*Chunk, @ptrCast(@alignCast(method.userdata))).execute();
+		}
+
+		fn typeinfo_destruct(method: Typeinfo.Method) void {
+			@as(*Chunk, @ptrCast(@alignCast(method.userdata))).free();
+		}
 	};
 
 	const ConstList = coral.list.Stack(*RuntimeRef);
@@ -967,7 +1005,7 @@ pub const RuntimeEnv = struct {
 		contiguous: RefList,
 
 		fn typeinfo_destruct(method: Typeinfo.Method) void {
-			const table = @as(*Table, @ptrCast(@alignCast(method.userdata.ptr)));
+			const table = @as(*Table, @ptrCast(@alignCast(method.userdata)));
 
 			{
 				var field_iterable = table.associative.as_iterable();
@@ -990,7 +1028,7 @@ pub const RuntimeEnv = struct {
 		}
 
 		fn typeinfo_get(method: Typeinfo.Method, index: *const RuntimeRef) RuntimeError!?*RuntimeRef {
-			const table = @as(*Table, @ptrCast(@alignCast(method.userdata.ptr)));
+			const table = @as(*Table, @ptrCast(@alignCast(method.userdata)));
 			const acquired_index = try method.env.acquire(index);
 
 			defer method.env.discard(acquired_index);
@@ -1014,7 +1052,7 @@ pub const RuntimeEnv = struct {
 		}
 
 		fn typeinfo_set(method: Typeinfo.Method, index: *const RuntimeRef, value: ?*const RuntimeRef) RuntimeError!void {
-			const table = @as(*Table, @ptrCast(@alignCast(method.userdata.ptr)));
+			const table = @as(*Table, @ptrCast(@alignCast(method.userdata)));
 			const acquired_index = try method.env.acquire(index);
 
 			errdefer method.env.discard(acquired_index);
@@ -1079,19 +1117,14 @@ pub const RuntimeEnv = struct {
 		return null;
 	}
 
-	pub fn bind_system(self: *RuntimeEnv, name: []const coral.io.Byte, value: *const RuntimeRef) RuntimeError!void {
+	pub fn acquire_args(self: *RuntimeEnv) RuntimeError!*RuntimeRef {
-		const name_symbol = try self.new_symbol(name);
+		const frame = self.frames.peek() orelse return self.raise(error.IllegalState, "stack underflow");
 
-		errdefer self.discard(name_symbol);
+		_ = frame;
 
-		const acquired_value = try self.acquire(value);
+		const args_table = self.new_table();
 
-		errdefer self.discard(acquired_value);
+		return args_table;
-
-		if (try self.system_bindings.replace(name_symbol, acquired_value)) |replaced| {
-			self.discard(replaced.key);
-			self.discard(replaced.value);
-		}
 	}
 
 	pub fn call(self: *RuntimeEnv, callable: *RuntimeRef, args: []const *RuntimeRef) RuntimeError!?*RuntimeRef {
@@ -1172,6 +1205,14 @@ pub const RuntimeEnv = struct {
 			error.OutOfMemory => error.OutOfMemory,
 		});
 
+		try self.frames.push_one(.{
+			.name = file_name,
+			.arg_count = 0,
+			.locals_top = self.locals.values.len,
+		});
+
+		defer coral.debug.assert(self.frames.pop() != null);
+
 		return chunk.execute();
 	}
 

source/ona/kym/ast.zig

@@ -74,6 +74,11 @@ pub const Expression = union (enum) {
 	table_literal: TableLiteral,
 	grouped_expression: *Expression,
 
+	lambda_literal: struct {
+		argument_identifiers: IdentifierList,
+		block_statements: Statement.List,
+	},
+
 	local_get: struct {
 		identifier: []const coral.io.Byte,
 	},
@@ -136,6 +141,8 @@ pub const DeclarationStorage = enum {
 
 const ExpressionBuilder = fn (self: *Tree) ParseError!Expression;
 
+const IdentifierList = coral.list.Stack([]const coral.io.Byte);
+
 pub const ParseError = error {
 	OutOfMemory,
 	BadSyntax,
@@ -221,8 +228,6 @@ pub const Tree = struct {
 	fn parse_branch(self: *Tree) ParseError!Statement {
 		const allocator = self.arena.as_allocator();
 
-		defer self.tokenizer.skip_newlines();
-
 		self.tokenizer.step();
 
 		const condition_expression = try self.parse_expression();
@@ -238,6 +243,8 @@ pub const Tree = struct {
 		while (true) {
 			switch (self.tokenizer.token) {
 				.keyword_end => {
+					self.tokenizer.skip_newlines();
+
 					return .{
 						.@"if" = .{
 							.condition_expression = condition_expression,
@@ -262,6 +269,8 @@ pub const Tree = struct {
 						try else_statements.push_one(try self.parse_statement());
 					}
 
+					self.tokenizer.skip_newlines();
+
 					return .{
 						.@"if" = .{
 							.else_statement = try coral.io.allocate_one(allocator, Statement{.block = else_statements}),
@@ -404,6 +413,57 @@ pub const Tree = struct {
 					break: parse .{.builtin = builtin};
 				},
 
+				.keyword_lambda => {
+					self.tokenizer.skip_newlines();
+
+					if (self.tokenizer.token != .symbol_paren_left) {
+						return self.report("expected `(` after opening lambda block");
+					}
+
+					var argument_identifiers = IdentifierList.make(allocator);
+
+					while (true) {
+						self.tokenizer.skip_newlines();
+
+						switch (self.tokenizer.token) {
+							.identifier => |identifier| try argument_identifiers.push_one(identifier),
+							.symbol_paren_right => break,
+							else => return self.report("expected identifier or closing `)` in argument list"),
+						}
+
+						self.tokenizer.skip_newlines();
+
+						switch (self.tokenizer.token) {
+							.symbol_comma => continue,
+							.symbol_paren_right => break,
+							else => return self.report("expected `,` or closing `)` after identifier in argument list"),
+						}
+					}
+
+					self.tokenizer.skip_newlines();
+
+					if (self.tokenizer.token != .symbol_colon) {
+						return self.report("expected `:` after closing `)` of lambda block argument list");
+					}
+
+					self.tokenizer.skip_newlines();
+
+					var block_statements = Statement.List.make(allocator);
+
+					while (self.tokenizer.token != .keyword_end) {
+						try block_statements.push_one(try self.parse_statement());
+					}
+
+					self.tokenizer.skip_newlines();
+
+					break: parse .{
+						.lambda_literal = .{
+							.argument_identifiers = argument_identifiers,
+							.block_statements = block_statements,
+						},
+					};
+				},
+
 				.symbol_brace_left => {
 					var table_literal = Expression.TableLiteral.make(allocator);
 

source/ona/kym/tokens.zig

@@ -46,6 +46,7 @@ pub const Token = union(enum) {
 	keyword_elif,
 	keyword_var,
 	keyword_let,
+	keyword_lambda,
 
 	pub fn text(self: Token) []const coral.io.Byte {
 		return switch (self) {
@@ -95,6 +96,7 @@ pub const Token = union(enum) {
 			.keyword_else => "else",
 			.keyword_var => "var",
 			.keyword_let => "let",
+			.keyword_lambda => "lambda",
 		};
 	}
 };
@@ -234,6 +236,12 @@ pub const Tokenizer = struct {
 						},
 
 						'l' => {
+							if (coral.io.ends_with(identifier, "ambda")) {
+								self.token = .keyword_lambda;
+
+								return;
+							}
+
 							if (coral.io.ends_with(identifier, "et")) {
 								self.token = .keyword_let;