Add syntax error reporting

debug/app.ona

@@ -1,4 +1,5 @@
 
+// Test comment.
 @log_info("game is loading")
 
 return {

source/coral/list.zig

@@ -118,5 +118,7 @@ pub fn stack_as_writer(self: *ByteStack) io.Writer {
 }
 
 fn write_stack(stack: *ByteStack, bytes: []const io.Byte) ?usize {
-	return stack.push_all(bytes) catch null;
+	stack.push_all(bytes) catch return null;
+
+	return bytes.len;
 }

source/coral/math.zig

@@ -30,7 +30,9 @@ pub fn max_int(comptime int: std.builtin.Type.Int) comptime_int {
 }
 
 pub fn min_int(comptime int: std.builtin.Type.Int) comptime_int {
-    if (int.signedness == .unsigned) return 0;
+	if (int.signedness == .unsigned) {
+		return 0;
+	}
 
 	const bit_count = int.bits;
 

source/ona/kym.zig

@@ -200,7 +200,7 @@ pub const RuntimeEnv = struct {
 		name: []const coral.io.Byte,
 		data: []const coral.io.Byte,
 	) RuntimeError!?*RuntimeRef {
-		var ast = Ast.make(self.allocator);
+		var ast = Ast.make(self.allocator, name);
 
 		defer ast.free();
 
@@ -208,7 +208,7 @@ pub const RuntimeEnv = struct {
 			var tokenizer = tokens.Tokenizer{.source = data};
 
 			ast.parse(&tokenizer) catch |parse_error| switch (parse_error) {
-				error.BadSyntax => return self.raise(error.BadSyntax, ast.error_message),
+				error.BadSyntax => return self.raise(error.BadSyntax, ast.error_message()),
 				error.OutOfMemory => return error.OutOfMemory,
 			};
 		}

source/ona/kym/Ast.zig

@@ -2,10 +2,11 @@ const coral = @import("coral");
 
 const tokens = @import("./tokens.zig");
 
+name: []const coral.io.Byte,
 allocator: coral.io.Allocator,
 arena: coral.arena.Stacking,
 statements: Statement.List,
-error_message: []const coral.io.Byte,
+error_buffer: coral.list.ByteStack,
 
 pub const Expression = union (enum) {
 	nil_literal,
@@ -114,7 +115,7 @@ fn binary_operation_parser(
 					tokenizer.step();
 
 					if (tokenizer.token == null) {
-						return self.raise("expected other half of expression after `" ++ comptime token.text() ++ "`");
+						return self.report(tokenizer, "expected other half of expression after `" ++ comptime token.text() ++ "`");
 					}
 
 					expression = .{
@@ -134,22 +135,32 @@ fn binary_operation_parser(
 	return BinaryOperationParser.parse;
 }
 
+pub fn error_message(self: Self) []const coral.io.Byte {
+	return self.error_buffer.values;
+}
+
 pub fn free(self: *Self) void {
 	self.arena.free();
 	self.statements.free();
+	self.error_buffer.free();
 }
 
-pub fn make(allocator: coral.io.Allocator) Self {
+pub fn make(allocator: coral.io.Allocator, ast_name: []const coral.io.Byte) Self {
 	return Self{
 		.arena = coral.arena.Stacking.make(allocator, 4096),
-		.allocator = allocator,
+		.error_buffer = coral.list.ByteStack.make(allocator),
 		.statements = Statement.List.make(allocator),
-		.error_message = "",
+		.allocator = allocator,
+		.name = ast_name,
 	};
 }
 
-fn raise(self: *Self, message: []const u8) ParseError {
+fn report(self: *Self, tokenizer: *tokens.Tokenizer, message: []const coral.io.Byte) ParseError {
-	self.error_message = message;
+	coral.utf8.print_formatted(coral.list.stack_as_writer(&self.error_buffer), "{name}@{line}: {message}", .{
+		.name = self.name,
+		.line = tokenizer.lines_stepped,
+		.message = message,
+	}) catch return error.OutOfMemory;
 
 	return error.BadSyntax;
 }
@@ -165,14 +176,12 @@ pub fn parse(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!void {
 	var has_returned = false;
 
 	while (true) {
-		const no_effect_message = "statement has no effect";
-
 		tokenizer.skip(.newline);
 
 		switch (tokenizer.token orelse return) {
 			.keyword_return => {
 				if (has_returned) {
-					return self.raise("multiple returns in function scope but expected only one");
+					return self.report(tokenizer, "multiple returns in function scope but expected only one");
 				}
 
 				try self.statements.push_one(get_statement: {
@@ -183,7 +192,7 @@ pub fn parse(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!void {
 					}
 
 					if (!tokenizer.is_token_null_or(.newline)) {
-						return self.raise("unexpected token after return");
+						return self.report(tokenizer, "unexpected token after return");
 					}
 
 					break: get_statement .return_nothing;
@@ -195,14 +204,16 @@ pub fn parse(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!void {
 			.identifier => |identifier| {
 				tokenizer.step();
 
-				switch (tokenizer.token orelse return self.raise(no_effect_message)) {
+				const no_effect_message = "statement has no effect";
-					.newline => return self.raise(no_effect_message),
+
+				switch (tokenizer.token orelse return self.report(tokenizer, no_effect_message)) {
+					.newline => return self.report(tokenizer, no_effect_message),
 
 					.symbol_equals => {
 						tokenizer.step();
 
 						if (tokenizer.token == null) {
-							return self.raise("expected expression after `=`");
+							return self.report(tokenizer, "expected expression after `=`");
 						}
 
 						try self.statements.push_one(.{
@@ -213,19 +224,21 @@ pub fn parse(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!void {
 						});
 
 						if (!tokenizer.is_token_null_or(.newline)) {
-							return self.raise("unexpected token after assignment");
+							return self.report(tokenizer, "unexpected token after assignment");
 						}
 					},
 
-					else => return self.raise("expected `=` after local"),
+					else => return self.report(tokenizer, "expected `=` after local"),
 				}
 			},
 
 			.special_identifier => |identifier| {
 				tokenizer.step();
 
-				switch (tokenizer.token orelse return self.raise(no_effect_message)) {
+				const missing_arguments_message = "system call is missing arguments";
-					.newline => return self.raise(no_effect_message),
+
+				switch (tokenizer.token orelse return self.report(tokenizer, missing_arguments_message)) {
+					.newline => return self.report(tokenizer, missing_arguments_message),
 
 					.symbol_paren_left => {
 						tokenizer.step();
@@ -239,10 +252,10 @@ pub fn parse(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!void {
 
 							try expressions_list.push_one(try self.parse_expression(tokenizer));
 
-							switch (tokenizer.token orelse return self.raise("unexpected end after after `(`")) {
+							switch (tokenizer.token orelse return self.report(tokenizer, "unexpected end after after `(`")) {
 								.symbol_comma => continue,
 								.symbol_paren_right => break,
-								else => return self.raise("expected `)` or argument after `(`"),
+								else => return self.report(tokenizer, "expected `)` or argument after `(`"),
 							}
 						}
 
@@ -256,11 +269,11 @@ pub fn parse(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!void {
 						});
 					},
 
-					else => return self.raise("expected `=` after local"),
+					else => return self.report(tokenizer, "expected `=` after local"),
 				}
 			},
 
-			else => return self.raise("invalid statement"),
+			else => return self.report(tokenizer, "invalid statement"),
 		}
 	}
 }
@@ -284,18 +297,18 @@ const parse_expression = binary_operation_parser(parse_equality, &.{
 fn parse_factor(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!Expression {
 	const allocator = self.arena.as_allocator();
 
-	switch (tokenizer.token orelse return self.raise("expected operand after operator")) {
+	switch (tokenizer.token orelse return self.report(tokenizer, "expected operand after operator")) {
 		.symbol_paren_left => {
 			tokenizer.skip(.newline);
 
 			if (tokenizer.token == null) {
-				return self.raise("expected an expression after `(`");
+				return self.report(tokenizer, "expected an expression after `(`");
 			}
 
 			const expression = try self.parse_expression(tokenizer);
 
 			if (!tokenizer.is_token(.symbol_paren_right)) {
-				return self.raise("expected a closing `)` after expression");
+				return self.report(tokenizer, "expected a closing `)` after expression");
 			}
 
 			tokenizer.step();
@@ -339,7 +352,7 @@ fn parse_factor(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!Expression
 			var expression_list = Expression.List.make(allocator);
 
 			while (true) {
-				switch (tokenizer.token orelse return self.raise("expected expression or `)` after `(`")) {
+				switch (tokenizer.token orelse return self.report(tokenizer, "expected expression or `)` after `(`")) {
 					.symbol_paren_right => {
 						tokenizer.step();
 
@@ -354,7 +367,7 @@ fn parse_factor(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!Expression
 					else => {
 						try expression_list.push_one(try self.parse_expression(tokenizer));
 
-						switch (tokenizer.token orelse return self.raise("expected `,` or `)` after argument")) {
+						switch (tokenizer.token orelse return self.report(tokenizer, "expected `,` or `)` after argument")) {
 							.symbol_comma => continue,
 
 							.symbol_paren_right => {
@@ -368,7 +381,7 @@ fn parse_factor(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!Expression
 								};
 							},
 
-							else => return self.raise("expected `,` or `)` after argument"),
+							else => return self.report(tokenizer, "expected `,` or `)` after argument"),
 						}
 					},
 				}
@@ -387,7 +400,7 @@ fn parse_factor(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!Expression
 			tokenizer.skip(.newline);
 
 			while (true) {
-				switch (tokenizer.token orelse return self.raise("unexpected end of table literal")) {
+				switch (tokenizer.token orelse return self.report(tokenizer, "unexpected end of table literal")) {
 					.symbol_brace_right => {
 						tokenizer.step();
 
@@ -398,13 +411,13 @@ fn parse_factor(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!Expression
 						tokenizer.skip(.newline);
 
 						if (!tokenizer.is_token(.symbol_equals)) {
-							return self.raise("expected `=` after identifier");
+							return self.report(tokenizer, "expected `=` after identifier");
 						}
 
 						tokenizer.skip(.newline);
 
 						if (tokenizer.token == null) {
-							return self.raise("unexpected end after `=`");
+							return self.report(tokenizer, "unexpected end after `=`");
 						}
 
 						try table_fields.push_one(.{
@@ -412,7 +425,7 @@ fn parse_factor(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!Expression
 							.identifier = identifier,
 						});
 
-						switch (tokenizer.token orelse return self.raise("unexpected end of table")) {
+						switch (tokenizer.token orelse return self.report(tokenizer, "unexpected end of table")) {
 							.symbol_comma => tokenizer.skip(.newline),
 
 							.symbol_brace_right => {
@@ -421,11 +434,11 @@ fn parse_factor(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!Expression
 								return Expression{.table_literal = table_fields};
 							},
 
-							else => return self.raise("expected `,` or `}` after expression"),
+							else => return self.report(tokenizer, "expected `,` or `}` after expression"),
 						}
 					},
 
-					else => return self.raise("expected `}` or fields in table literal"),
+					else => return self.report(tokenizer, "expected `}` or fields in table literal"),
 				}
 			}
 		},
@@ -434,7 +447,7 @@ fn parse_factor(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!Expression
 			tokenizer.skip(.newline);
 
 			if (tokenizer.token == null) {
-				return self.raise("expected expression after numeric negation (`-`)");
+				return self.report(tokenizer, "expected expression after numeric negation (`-`)");
 			}
 
 			return Expression{
@@ -449,7 +462,7 @@ fn parse_factor(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!Expression
 			tokenizer.skip(.newline);
 
 			if (tokenizer.token == null) {
-				return self.raise("expected expression after boolean negation (`!`)");
+				return self.report(tokenizer, "expected expression after boolean negation (`!`)");
 			}
 
 			return Expression{
@@ -460,7 +473,7 @@ fn parse_factor(self: *Self, tokenizer: *tokens.Tokenizer) ParseError!Expression
 			};
 		},
 
-		else => return self.raise("unexpected token in expression"),
+		else => return self.report(tokenizer, "unexpected token in expression"),
 	}
 }
 

source/ona/ona.zig

@@ -11,6 +11,8 @@ const heap = @import("./heap.zig");
 const kym = @import("./kym.zig");
 
 fn kym_handle_errors(info: kym.ErrorInfo) void {
+	app.log_fail(info.message);
+
 	var remaining_frames = info.frames.len;
 
 	while (remaining_frames != 0) {
@@ -62,6 +64,10 @@ pub fn run_app(file_access: file.Access) void {
 			.name = "log_info",
 			.caller = kym.Caller.from(kym_log_info),
 		},
+		.{
+			.name = "log_warn",
+			.caller = kym.Caller.from(kym_log_warn),
+		},
 		.{
 			.name = "log_fail",
 			.caller = kym.Caller.from(kym_log_fail),