Fix > and == operators being miscompiled

debug/app.ona

@@ -1,12 +1,20 @@
 
 i = 0
 
-while i < 5 do
+while i < 5:
 	@print("hello, world")
 
 	i = i + 1
 end
 
+if i > 6:
+	@print("`i` greater than `6`")
+elif i == 4:
+	@print("`i` is equal to `4`")
+else:
+	@print("i'unno")
+end
+
 return {
 	.title = "Game",
 	.width = 1280,

source/ona/kym.zig

@@ -36,6 +36,7 @@ pub const RuntimeEnv = struct {
 		};
 
 		const Opcode = union (enum) {
+			pop,
 			push_nil,
 			push_true,
 			push_false,
@@ -135,9 +136,9 @@ pub const RuntimeEnv = struct {
 							.subtraction => .sub,
 							.multiplication => .mul,
 							.divsion => .div,
-							.greater_equals_comparison => .eql,
+							.greater_equals_comparison => .cge,
 							.greater_than_comparison => .cgt,
-							.equals_comparison => .cge,
+							.equals_comparison => .eql,
 							.less_than_comparison => .clt,
 							.less_equals_comparison => .cle,
 						});
@@ -263,13 +264,19 @@ pub const RuntimeEnv = struct {
 			fn compile_statement(self: *CompilationUnit, chunk: *Chunk, statement: ast.Statement) RuntimeError!void {
 				switch (statement) {
 					.@"return" => |@"return"| {
-						if (@"return".expression) |expression| {
+						if (@"return") |expression| {
 							try self.compile_expression(chunk, expression);
 						} else {
 							try chunk.opcodes.push_one(.push_nil);
 						}
 					},
 
+					.block => |block| {
+						for (block.values) |block_statement| {
+							try self.compile_statement(chunk, block_statement);
+						}
+					},
+
 					.@"while" => |@"while"| {
 						try self.compile_expression(chunk, @"while".condition_expression);
 						try chunk.opcodes.push_one(.{.jf = 0});
@@ -280,8 +287,6 @@ pub const RuntimeEnv = struct {
 							try self.compile_statement(chunk, block_statement);
 						}
 
-						coral.debug.assert(chunk.opcodes.values.len < coral.math.max_int(@typeInfo(u32).Int));
-
 						chunk.opcodes.values[origin_index].jf = @intCast(chunk.opcodes.values.len - 1);
 
 						try self.compile_expression(chunk, @"while".condition_expression);
@@ -298,12 +303,20 @@ pub const RuntimeEnv = struct {
 							try self.compile_statement(chunk, block_statement);
 						}
 
-						coral.debug.assert(chunk.opcodes.values.len < coral.math.max_int(@typeInfo(u32).Int));
-
 						chunk.opcodes.values[origin_index].jf = @intCast(chunk.opcodes.values.len - 1);
+
+						if (@"if".else_statement) |else_statement| {
+							try self.compile_statement(chunk, else_statement.*);
+						}
 					},
 
-					.expression => |expression| try self.compile_expression(chunk, expression),
+					.expression => |expression| {
+						try self.compile_expression(chunk, expression);
+
+						if (expression == .invoke) {
+							try chunk.opcodes.push_one(.pop);
+						}
+					},
 				}
 			}
 
@@ -326,10 +339,10 @@ pub const RuntimeEnv = struct {
 			}
 		};
 
-		fn compile(self: *Chunk, statements: *const ast.StatementList) RuntimeError!void {
+		fn compile(self: *Chunk, statements: []const ast.Statement) RuntimeError!void {
 			var unit = CompilationUnit{};
 
-			for (statements.values) |statement| {
+			for (statements) |statement| {
 				try unit.compile_statement(self, statement);
 			}
 		}
@@ -364,6 +377,12 @@ pub const RuntimeEnv = struct {
 
 			while (opcode_cursor < self.opcodes.values.len) : (opcode_cursor += 1) {
 				switch (self.opcodes.values[opcode_cursor]) {
+					.pop => {
+						if (try self.pop_local()) |ref| {
+							self.env.discard(ref);
+						}
+					},
+
 					.push_nil => try self.env.locals.push_one(null),
 					.push_true => try self.env.locals.push_one(try self.env.new_boolean(true)),
 					.push_false => try self.env.locals.push_one(try self.env.new_boolean(false)),

source/ona/kym/ast.zig

@@ -118,9 +118,11 @@ pub const Expression = union (enum) {
 
 	invoke: struct {
 		object_expression: *Expression,
-		argument_expressions: ExpressionList,
+		argument_expressions: List,
 	},
 
+	const List = coral.list.Stack(Expression);
+
 	const TableLiteral = coral.list.Stack(struct {
 		key_expression: Expression,
 		value_expression: Expression,
@@ -129,37 +131,38 @@ pub const Expression = union (enum) {
 
 const ExpressionBuilder = fn (self: *Tree) ParseError!Expression;
 
-pub const ExpressionList = coral.list.Stack(Expression);
-
 pub const ParseError = error {
 	OutOfMemory,
 	BadSyntax,
 };
 
 pub const Statement = union (enum) {
-	@"return": struct {
-		expression: ?Expression,
+	@"return": ?Expression,
+
+	@"if": struct {
+		condition_expression: Expression,
+		block_statements: List,
+		else_statement: ?*Statement,
 	},
 
-	@"if": ConditionalBlock,
-	@"while": ConditionalBlock,
+	@"while": struct {
+		condition_expression: Expression,
+		block_statements: List,
+	},
+
+	block: List,
 	expression: Expression,
 
-	const ConditionalBlock = struct {
-		condition_expression: Expression,
-		block_statements: StatementList,
-	};
+	const List = coral.list.Stack(Statement);
 };
 
-pub const StatementList = coral.list.Stack(Statement);
-
 pub const Tree = struct {
 	name: []const coral.io.Byte,
 	allocator: coral.io.Allocator,
 	arena: coral.arena.Stacking,
 	error_buffer: coral.list.ByteStack,
 	tokenizer: tokens.Tokenizer,
-	parsed_statements: StatementList,
+	parsed_statements: Statement.List,
 	has_returned: bool,
 
 	pub fn error_message(self: Tree) []const coral.io.Byte {
@@ -176,7 +179,7 @@ pub const Tree = struct {
 		return .{
 			.arena = coral.arena.Stacking.make(allocator, 4096),
 			.error_buffer = coral.list.ByteStack.make(allocator),
-			.parsed_statements = StatementList.make(allocator),
+			.parsed_statements = Statement.List.make(allocator),
 			.tokenizer = .{.source = ""},
 			.allocator = allocator,
 			.name = ast_name,
@@ -184,19 +187,19 @@ pub const Tree = struct {
 		};
 	}
 
-	pub fn parse(self: *Tree, data: []const coral.io.Byte) ParseError!*const StatementList {
+	pub fn parse(self: *Tree, data: []const coral.io.Byte) ParseError![]const Statement {
+		self.free();
+
 		self.tokenizer = .{.source = data};
 		self.has_returned = false;
 
-		self.parsed_statements.free();
+		self.tokenizer.skip_newlines();
 
-		self.parsed_statements = try self.parse_statements();
-
-		if (self.tokenizer.token == .keyword_end) {
-			return self.report("unexpected `end` without matching `do` block");
+		while (self.tokenizer.token != .end) {
+			try self.parsed_statements.push_one(try self.parse_statement());
 		}
 
-		return &self.parsed_statements;
+		return self.parsed_statements.values;
 	}
 
 	const parse_additive = BinaryOperator.builder(parse_equality, &.{
@@ -204,6 +207,74 @@ pub const Tree = struct {
 		.subtraction,
 	});
 
+	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();
+
+		if (self.tokenizer.token != .symbol_colon) {
+			return self.report("expected `:` after `if` statement condition");
+		}
+
+		var statements = Statement.List.make(allocator);
+
+		self.tokenizer.skip_newlines();
+
+		while (true) {
+			switch (self.tokenizer.token) {
+				.keyword_end => {
+					return .{
+						.@"if" = .{
+							.condition_expression = condition_expression,
+							.block_statements = statements,
+							.else_statement = null,
+						},
+					};
+				},
+
+				.keyword_else => {
+					self.tokenizer.step();
+
+					if (self.tokenizer.token != .symbol_colon) {
+						return self.report("expected `:` after `if` statement condition");
+					}
+
+					var else_statements = Statement.List.make(allocator);
+
+					self.tokenizer.skip_newlines();
+
+					while (self.tokenizer.token != .keyword_end) {
+						try else_statements.push_one(try self.parse_statement());
+					}
+
+					return .{
+						.@"if" = .{
+							.else_statement = try coral.io.allocate_one(allocator, Statement{.block = else_statements}),
+							.condition_expression = condition_expression,
+							.block_statements = statements,
+						},
+					};
+				},
+
+				.keyword_elif => {
+					return .{
+						.@"if" = .{
+							.else_statement = try coral.io.allocate_one(allocator, try self.parse_branch()),
+							.condition_expression = condition_expression,
+							.block_statements = statements,
+						},
+					};
+				},
+
+				else => try statements.push_one(try self.parse_statement()),
+			}
+		}
+	}
+
 	const parse_comparison = BinaryOperator.builder(parse_term, &.{
 		.greater_than_comparison,
 		.greater_equals_comparison,
@@ -486,7 +557,7 @@ pub const Tree = struct {
 				},
 
 				.symbol_paren_left => {
-					var argument_expressions = ExpressionList.make(allocator);
+					var argument_expressions = Expression.List.make(allocator);
 
 					while (true) {
 						self.tokenizer.skip_newlines();
@@ -526,25 +597,21 @@ pub const Tree = struct {
 		return expression;
 	}
 
-	fn parse_statements(self: *Tree) ParseError!StatementList {
-		var statements = StatementList.make(self.arena.as_allocator());
+	fn parse_statement(self: *Tree) ParseError!Statement {
+		const allocator = self.arena.as_allocator();
 
-		self.tokenizer.skip_newlines();
-
-		while (true) {
-			try statements.push_one(parse_statement: {
 		switch (self.tokenizer.token) {
-					.end, .keyword_end => return statements,
-
 			.keyword_return => {
+				defer self.tokenizer.skip_newlines();
+
 				if (self.has_returned) {
-							return self.report("multiple returns in function scope but expected only one");
+					return self.report("multiple returns in lambda scope but expected only one");
 				}
 
 				self.tokenizer.step();
 
 				if (self.tokenizer.token != .end and self.tokenizer.token != .newline) {
-							break: parse_statement .{.@"return" = .{.expression = try self.parse_expression()}};
+					return .{.@"return" = try self.parse_expression()};
 				}
 
 				if (self.tokenizer.token != .end and self.tokenizer.token != .newline) {
@@ -553,66 +620,38 @@ pub const Tree = struct {
 
 				self.has_returned = true;
 
-						break: parse_statement .{.@"return" = .{.expression = null}};
+				return .{.@"return" = null};
 			},
 
 			.keyword_while => {
+				defer self.tokenizer.skip_newlines();
+
 				self.tokenizer.step();
 
 				const condition_expression = try self.parse_expression();
 
-						if (self.tokenizer.token != .keyword_do) {
-							return self.report("expected `do` block after `while` statement");
+				if (self.tokenizer.token != .symbol_colon) {
+					return self.report("expected `:` after `while` statement");
 				}
 
-						self.tokenizer.step();
+				var statements = Statement.List.make(allocator);
 
-						const while_statement = Statement{
+				self.tokenizer.skip_newlines();
+
+				while (self.tokenizer.token != .keyword_end) {
+					try statements.push_one(try self.parse_statement());
+				}
+
+				return .{
 					.@"while" = .{
-								.block_statements = try self.parse_statements(),
+						.block_statements = statements,
 						.condition_expression = condition_expression,
 					},
 				};
-
-						if (self.tokenizer.token != .keyword_end) {
-							return self.report("expected `end` after block");
-						}
-
-						self.tokenizer.skip_newlines();
-
-						break: parse_statement while_statement;
 			},
 
-					.keyword_if => {
-						self.tokenizer.step();
-
-						const condition_expression = try self.parse_expression();
-
-						if (self.tokenizer.token != .keyword_do) {
-							return self.report("expected `do` block after `if` statement");
-						}
-
-						self.tokenizer.step();
-
-						const if_statement = Statement{
-							.@"if" = .{
-								.block_statements = try self.parse_statements(),
-								.condition_expression = condition_expression,
-							},
-						};
-
-						if (self.tokenizer.token != .keyword_end) {
-							return self.report("expected `end` after block");
-						}
-
-						self.tokenizer.skip_newlines();
-
-						break: parse_statement if_statement;
-					},
-
-					else => break: parse_statement .{.expression = try self.parse_expression()},
-				}
-			});
+			.keyword_if => return self.parse_branch(),
+			else => return .{.expression = try self.parse_expression()},
 		}
 	}
 

source/ona/kym/tokens.zig

@@ -21,7 +21,7 @@ pub const Token = union(enum) {
 	symbol_bracket_left,
 	symbol_bracket_right,
 	symbol_period,
-	symbol_lambda,
+	symbol_colon,
 	symbol_less_than,
 	symbol_less_equals,
 	symbol_greater_than,
@@ -42,6 +42,8 @@ pub const Token = union(enum) {
 	keyword_do,
 	keyword_end,
 	keyword_while,
+	keyword_else,
+	keyword_elif,
 
 	pub fn text(self: Token) []const coral.io.Byte {
 		return switch (self) {
@@ -66,7 +68,7 @@ pub const Token = union(enum) {
 			.symbol_bracket_left => "[",
 			.symbol_bracket_right => "]",
 			.symbol_period => ".",
-			.symbol_lambda => "=>",
+			.symbol_colon => ":",
 			.symbol_less_than => "<",
 			.symbol_less_equals => "<=",
 			.symbol_greater_than => ">",
@@ -87,6 +89,8 @@ pub const Token = union(enum) {
 			.keyword_do => "do",
 			.keyword_end => "end",
 			.keyword_while => "while",
+			.keyword_elif => "elif",
+			.keyword_else => "else",
 		};
 	}
 };
@@ -94,7 +98,7 @@ pub const Token = union(enum) {
 pub const Tokenizer = struct {
 	source: []const coral.io.Byte,
 	lines_stepped: usize = 1,
-	token: Token = .end,
+	token: Token = .newline,
 
 	pub fn skip_newlines(self: *Tokenizer) void {
 		self.step();
@@ -190,6 +194,18 @@ pub const Tokenizer = struct {
 						},
 
 						'e' => {
+							if (coral.io.ends_with(identifier, "lse")) {
+								self.token = .keyword_else;
+
+								return;
+							}
+
+							if (coral.io.ends_with(identifier, "lif")) {
+								self.token = .keyword_elif;
+
+								return;
+							}
+
 							if (coral.io.ends_with(identifier, "nd")) {
 								self.token = .keyword_end;
 
@@ -378,6 +394,13 @@ pub const Tokenizer = struct {
 					return;
 				},
 
+				':' => {
+					self.token = .symbol_colon;
+					cursor += 1;
+
+					return;
+				},
+
 				'=' => {
 					cursor += 1;
 
@@ -390,13 +413,6 @@ pub const Tokenizer = struct {
 								return;
 							},
 
-							'>' => {
-								cursor += 1;
-								self.token = .symbol_lambda;
-
-								return;
-							},
-
 							else => {},
 						}
 					}