Implement basic tests and error unions

bootstrap/backend/llvm.zig

@@ -1180,7 +1180,13 @@ pub const LLVM = struct {
                     for (sema_function_prototype.argument_types) |argument_type_index| {
                         switch (unit.types.get(argument_type_index).*) {
                             // TODO: ABI
-                            .integer, .pointer, .@"enum", .@"struct", .slice, .bool, => try parameter_types.append(context.allocator, try llvm.getType(unit, context, argument_type_index)),
+                            .integer,
+                            .pointer,
+                            .@"enum",
+                            .@"struct",
+                            .slice,
+                            .bool,
+                            => try parameter_types.append(context.allocator, try llvm.getType(unit, context, argument_type_index)),
                             else => |t| @panic(@tagName(t)),
                         }
                         // arg_types.appendAssumeCapacity(llvm_argument_type);
@@ -1262,6 +1268,39 @@ pub const LLVM = struct {
                     const array_type = LLVM.Type.Array.get(element_type, array.count + @intFromBool(extra_element)) orelse return Type.Error.array;
                     break :blk array_type.toType();
                 },
+                .error_union => |error_union| {
+                    const error_type = try llvm.getType(unit, context, error_union.@"error");
+                    const payload_type = try llvm.getType(unit, context, error_union.type);
+                    const payload_type_size = unit.types.get(error_union.type).getBitSize(unit);
+
+                    switch (payload_type_size) {
+                        0 => {
+                            const integer_type = llvm.context.getIntegerType(31) orelse unreachable;
+                            const boolean_type = try llvm.getType(unit, context, .bool);
+                            const types = [2]*LLVM.Type{ integer_type.toType(), boolean_type };
+                            const is_packed = false;
+                            const struct_type = llvm.context.getStructType(&types, types.len, is_packed) orelse return Type.Error.@"struct";
+                            return struct_type.toType();
+                        },
+                        else => unreachable,
+                    }
+                    _ = error_type;
+                    _ = payload_type;
+                    unreachable;
+                },
+                .error_set => |error_set_index| b: {
+                    const error_set = unit.error_sets.get(error_set_index);
+                    if (error_set.values.items.len > 0) {
+                        unreachable;
+                    } else {
+                        const integer_type = llvm.context.getIntegerType(32) orelse unreachable;
+                        break :b integer_type.toType();
+                    }
+                },
+                .@"error" => b: {
+                    const integer_type = llvm.context.getIntegerType(31) orelse unreachable;
+                    break :b integer_type.toType();
+                },
                 else => |t| @panic(@tagName(t)),
             };
 
@@ -1327,7 +1366,13 @@ pub const LLVM = struct {
 
                             break :b name.items;
                         } else {
-                            unreachable;
+                            if (unit.type_declarations.get(sema_type_index)) |type_declaration| {
+                                _ = type_declaration; // autofix
+                                unreachable;
+                            } else {
+                                // TODO: fix
+                                break :b "anon_struct";
+                            }
                         }
                     },
                     // TODO: termination
@@ -2031,7 +2076,7 @@ pub const LLVM = struct {
         }
     }
 
-    fn emitComptimeRightValue(llvm: *LLVM, unit: *Compilation.Unit, context: *const Compilation.Context, ct: Compilation.V.Comptime, type_index: Compilation.Type.Index) !*LLVM.Value.Constant {
+    fn emitComptimeRightValue(llvm: *LLVM, unit: *Compilation.Unit, context: *const Compilation.Context, ct: Compilation.V.Comptime, type_index: Compilation.Type.Index) anyerror!*LLVM.Value.Constant {
         switch (ct) {
             .constant_int => |integer| {
                 const integer_type = unit.types.get(type_index);
@@ -2083,21 +2128,7 @@ pub const LLVM = struct {
                 const constant_int = llvm.context.getConstantInt(backing_integer_type.bit_count, value, signed) orelse unreachable;
                 return constant_int.toConstant();
             },
-            .constant_struct => |constant_struct_index| {
+            .constant_struct => |constant_struct_index| return try llvm.getConstantStruct(unit, context, constant_struct_index),
-                const constant_struct = unit.constant_structs.get(constant_struct_index);
-                var field_values = try ArrayList(*LLVM.Value.Constant).initCapacity(context.allocator, constant_struct.fields.len);
-                const sema_struct_type = unit.structs.get(unit.types.get(constant_struct.type).@"struct");
-                for (constant_struct.fields, sema_struct_type.fields.items) |field_value, field_index| {
-                    const field = unit.struct_fields.get(field_index);
-                    const constant = try llvm.emitComptimeRightValue(unit, context, field_value, field.type);
-                    field_values.appendAssumeCapacity(constant);
-                }
-
-                const llvm_type = try llvm.getType(unit, context, constant_struct.type);
-                const struct_type = llvm_type.toStruct() orelse unreachable;
-                const const_struct = struct_type.getConstant(field_values.items.ptr, field_values.items.len) orelse unreachable;
-                return const_struct;
-            },
             .undefined => {
                 const undefined_type = try llvm.getType(unit, context, type_index);
                 const poison = undefined_type.getPoison() orelse unreachable;
@@ -2130,6 +2161,13 @@ pub const LLVM = struct {
                 const constant_null_pointer = pointer_type.getNull();
                 return constant_null_pointer.toConstant();
             },
+            .error_value => |error_field_index| {
+                const error_field = unit.error_fields.get(error_field_index);
+                const signed = false;
+                const bit_count = 31;
+                const constant_int = llvm.context.getConstantInt(bit_count, error_field.value, signed) orelse unreachable;
+                return constant_int.toConstant();
+            },
             else => |t| @panic(@tagName(t)),
         }
     }
@@ -2192,9 +2230,10 @@ pub const LLVM = struct {
         const const_slice = unit.constant_slices.get(constant_slice_index);
         const const_slice_type = try llvm.getType(unit, context, const_slice.type);
         const slice_struct_type = const_slice_type.toStruct() orelse unreachable;
-        const ptr = llvm.global_variable_map.get(const_slice.ptr).?;
+        const ptr = llvm.global_variable_map.get(const_slice.array).?;
         const signed = false;
-        const len = llvm.context.getConstantInt(@bitSizeOf(usize), const_slice.len, signed) orelse unreachable;
+        assert(const_slice.start == 0);
+        const len = llvm.context.getConstantInt(@bitSizeOf(usize), const_slice.end, signed) orelse unreachable;
         const slice_fields = [2]*LLVM.Value.Constant{
             ptr.toConstant(),
             len.toConstant(),
@@ -2223,6 +2262,7 @@ pub const LLVM = struct {
                     break :b constant_int.toConstant();
                 },
                 .constant_slice => |constant_slice_index| try llvm.getConstantSlice(unit, context, constant_slice_index),
+                .constant_struct => |constant_struct_index| try llvm.getConstantStruct(unit, context, constant_struct_index),
                 else => |t| @panic(@tagName(t)),
             };
             list.appendAssumeCapacity(value);
@@ -2232,6 +2272,22 @@ pub const LLVM = struct {
         return result;
     }
 
+    fn getConstantStruct(llvm: *LLVM, unit: *Compilation.Unit, context: *const Compilation.Context, constant_struct_index: Compilation.V.Comptime.ConstantStruct.Index) !*LLVM.Value.Constant {
+        const constant_struct = unit.constant_structs.get(constant_struct_index);
+        var field_values = try ArrayList(*LLVM.Value.Constant).initCapacity(context.allocator, constant_struct.fields.len);
+        const sema_struct_type = unit.structs.get(unit.types.get(constant_struct.type).@"struct");
+        for (constant_struct.fields, sema_struct_type.fields.items) |field_value, field_index| {
+            const field = unit.struct_fields.get(field_index);
+            const constant = try llvm.emitComptimeRightValue(unit, context, field_value, field.type);
+            field_values.appendAssumeCapacity(constant);
+        }
+
+        const llvm_type = try llvm.getType(unit, context, constant_struct.type);
+        const struct_type = llvm_type.toStruct() orelse unreachable;
+        const const_struct = struct_type.getConstant(field_values.items.ptr, field_values.items.len) orelse unreachable;
+        return const_struct;
+    }
+
     fn callIntrinsic(llvm: *LLVM, intrinsic_name: []const u8, intrinsic_parameter_types: []const *LLVM.Type, intrinsic_arguments: []const *LLVM.Value) !*LLVM.Value {
         const intrinsic_id = LLVM.lookupIntrinsic(intrinsic_name.ptr, intrinsic_name.len);
         assert(intrinsic_id != .none);
@@ -2354,7 +2410,6 @@ pub const LLVM = struct {
             }
         }
     }
-
 };
 
 fn getCallingConvention(calling_convention: Compilation.Function.CallingConvention) LLVM.Value.Constant.Function.CallingConvention {
@@ -2508,6 +2563,8 @@ pub fn codegen(unit: *Compilation.Unit, context: *const Compilation.Context) !vo
         const entry_block_node = try llvm.createBasicBlock(context, function_definition.basic_blocks.items[0], "fn_entry");
         block_command_list.append(entry_block_node);
 
+        var phis = AutoArrayHashMap(Compilation.Instruction.Index, *LLVM.Value.Instruction.PhiNode){};
+
         while (block_command_list.len != 0) {
             const block_node = block_command_list.first orelse unreachable;
             const basic_block_index = block_node.data;
@@ -2625,14 +2682,8 @@ pub fn codegen(unit: *Compilation.Unit, context: *const Compilation.Context) !vo
                         switch (unit.types.get(stack_slot.type).*) {
                             .void, .noreturn, .type => unreachable,
                             .comptime_int => unreachable,
-                            .bool => {},
-                            .@"struct" => {},
-                            .@"enum" => {},
                             .function => unreachable,
-                            .integer => {},
+                            else => {},
-                            .pointer => {},
-                            .slice => {},
-                            .array => {},
                         }
 
                         const declaration_type = try llvm.getType(unit, context, stack_slot.type);
@@ -2769,7 +2820,6 @@ pub fn codegen(unit: *Compilation.Unit, context: *const Compilation.Context) !vo
                                         else => |t| @panic(@tagName(t)),
                                     };
 
-
                                     for (call.arguments, arguments) |argument_value, *argument| {
                                         argument.* = try llvm.emitRightValue(unit, context, argument_value);
                                     }
@@ -2883,15 +2933,8 @@ pub fn codegen(unit: *Compilation.Unit, context: *const Compilation.Context) !vo
                         switch (unit.types.get(argument_type_index).*) {
                             .void, .noreturn, .type => unreachable,
                             .comptime_int => unreachable,
-                            .bool => {},
-                            // .bool => unreachable,
-                            .@"struct" => {},
-                            .@"enum" => {},
                             .function => unreachable,
-                            .integer => {},
+                            else => {},
-                            .pointer => {},
-                            .slice => {},
-                            .array => {},
                         }
                         const argument_type = argument.toValue().getType();
                         const alloca_array_size: ?*LLVM.Value = null;
@@ -3047,6 +3090,8 @@ pub fn codegen(unit: *Compilation.Unit, context: *const Compilation.Context) !vo
                         const not_taken_node = try llvm.createBasicBlock(context, branch.not_taken, "not_taken_block");
                         block_command_list.insertAfter(block_node, taken_node);
                         block_command_list.insertAfter(taken_node, not_taken_node);
+                        // block_command_list.append(taken_node);
+                        // block_command_list.append(taken_node);
 
                         // TODO: make this fast
                         const taken_block = llvm.llvm_block_map.get(taken_node.data).?;
@@ -3064,11 +3109,7 @@ pub fn codegen(unit: *Compilation.Unit, context: *const Compilation.Context) !vo
                         const phi_name = "phi";
                         const phi_node = llvm.builder.createPhi(phi_type, reserved_value_count, phi_name, phi_name.len) orelse unreachable;
 
-                        for (phi.values.items, phi.basic_blocks.items) |sema_value, sema_block| {
+                        try phis.putNoClobber(context.allocator, instruction_index, phi_node);
-                            const value = llvm.llvm_value_map.get(sema_value) orelse try llvm.emitRightValue(unit, context, sema_value);
-                            const value_basic_block = llvm.llvm_block_map.get(sema_block).?;
-                            phi_node.addIncoming(value, value_basic_block);
-                        }
 
                         try llvm.llvm_instruction_map.putNoClobber(context.allocator, instruction_index, phi_node.toValue());
                     },
@@ -3106,6 +3147,16 @@ pub fn codegen(unit: *Compilation.Unit, context: *const Compilation.Context) !vo
             _ = block_command_list.popFirst();
         }
 
+        for (phis.keys(), phis.values()) |instruction_index, phi| {
+            const instruction = unit.instructions.get(instruction_index);
+            const sema_phi = instruction.phi;
+            for (sema_phi.values.items, sema_phi.basic_blocks.items) |sema_value, sema_block| {
+                const value_basic_block = llvm.llvm_block_map.get(sema_block).?;
+                const value = llvm.llvm_value_map.get(sema_value) orelse try llvm.emitRightValue(unit, context, sema_value);
+                phi.addIncoming(value, value_basic_block);
+            }
+        }
+
         if (!builder.isCurrentBlockTerminated()) {
             var message_len: usize = 0;
             const function_str = llvm.function.toString(&message_len);
@@ -3228,7 +3279,7 @@ pub fn codegen(unit: *Compilation.Unit, context: *const Compilation.Context) !vo
             try arguments.append(context.allocator, "-lSystem");
         },
         .linux => {
-            try arguments.appendSlice(context.allocator, &.{"--entry", "_start"});
+            try arguments.appendSlice(context.allocator, &.{ "--entry", "_start" });
             try arguments.append(context.allocator, "-m");
             try arguments.append(context.allocator, switch (unit.descriptor.target.cpu.arch) {
                 .x86_64 => "elf_x86_64",
@@ -3238,8 +3289,8 @@ pub fn codegen(unit: *Compilation.Unit, context: *const Compilation.Context) !vo
             if (unit.descriptor.link_libc) {
                 try arguments.append(context.allocator, "/usr/lib/crt1.o");
                 try arguments.append(context.allocator, "/usr/lib/crti.o");
-                try arguments.appendSlice(context.allocator, &.{"-L", "/usr/lib"});
+                try arguments.appendSlice(context.allocator, &.{ "-L", "/usr/lib" });
-                try arguments.appendSlice(context.allocator, &.{"-dynamic-linker", "/lib64/ld-linux-x86-64.so.2"});
+                try arguments.appendSlice(context.allocator, &.{ "-dynamic-linker", "/lib64/ld-linux-x86-64.so.2" });
                 try arguments.append(context.allocator, "--as-needed");
                 try arguments.append(context.allocator, "-lm");
                 try arguments.append(context.allocator, "-lpthread");

bootstrap/data_structures.zig

@@ -100,7 +100,7 @@ pub fn getIndexForType(comptime T: type, comptime E: type) type {
     const EnumField = std.builtin.Type.EnumField;
     comptime var fields: []const EnumField = &.{};
     // comptime var enum_value: comptime_int = 0;
-        fields = fields ++ @typeInfo(E).Enum.fields;
+    fields = fields ++ @typeInfo(E).Enum.fields;
 
     // for (names) |name| {
     //     fields = fields ++ [1]EnumField{.{
@@ -137,32 +137,31 @@ pub fn getIndexForType(comptime T: type, comptime E: type) type {
             return @enumFromInt(value);
         }
 
-        pub fn addInt(this: Index, value: IndexType) Index{
+        pub fn addInt(this: Index, value: IndexType) Index {
             const this_int = @intFromEnum(this);
             return @enumFromInt(this_int + value);
         }
 
-        pub fn subInt(this: Index, value: IndexType) IndexType{
+        pub fn subInt(this: Index, value: IndexType) IndexType {
             const this_int = @intFromEnum(this);
             return this_int - value;
         }
 
-        pub fn add(a: Index, b: Index) Index{
+        pub fn add(a: Index, b: Index) Index {
             return @enumFromInt(@intFromEnum(a) + @intFromEnum(b));
         }
 
-        pub fn sub(a: Index, b: Index) IndexType{
+        pub fn sub(a: Index, b: Index) IndexType {
             return @intFromEnum(a) - @intFromEnum(b);
         }
     };
 }
 
-pub const ListType = enum{
+pub const ListType = enum {
     index,
     pointer,
 };
 
-
 pub fn enumFromString(comptime E: type, string: []const u8) ?E {
     return inline for (@typeInfo(E).Enum.fields) |enum_field| {
         if (std.mem.eql(u8, string, enum_field.name)) {

bootstrap/frontend/lexer.zig

@@ -15,7 +15,6 @@ const logln = Compilation.logln;
 const Token = Compilation.Token;
 const fs = @import("../fs.zig");
 
-
 // Needed information
 // Token: u8
 // line: u32
@@ -76,7 +75,7 @@ pub fn analyze(allocator: Allocator, text: []const u8, token_buffer: *Token.Buff
 
     try token_buffer.tokens.ensureUnusedCapacity(allocator, text.len / 4);
 
-    logln(.lexer, .end, "START LEXER - TOKEN OFFSET: {} - LINE OFFSET: {}", .{Token.unwrap(lexer.offset), lexer.line_offset});
+    logln(.lexer, .end, "START LEXER - TOKEN OFFSET: {} - LINE OFFSET: {}", .{ Token.unwrap(lexer.offset), lexer.line_offset });
 
     while (index < len) {
         const start_index = index;
@@ -229,7 +228,7 @@ pub fn analyze(allocator: Allocator, text: []const u8, token_buffer: *Token.Buff
                         index += 1;
                         break :blk .operator_compare_less_equal;
                     },
-                    else =>break :blk .operator_compare_less,
+                    else => break :blk .operator_compare_less,
                 }
             },
             '>' => blk: {
@@ -249,7 +248,7 @@ pub fn analyze(allocator: Allocator, text: []const u8, token_buffer: *Token.Buff
                         index += 1;
                         break :blk .operator_compare_greater_equal;
                     },
-                    else =>break :blk .operator_compare_greater,
+                    else => break :blk .operator_compare_greater,
                 }
             },
             ';' => blk: {
@@ -281,7 +280,6 @@ pub fn analyze(allocator: Allocator, text: []const u8, token_buffer: *Token.Buff
                     },
                     else => break :blk .operator_bang,
                 }
-               
             },
             '=' => blk: {
                 index += 1;
@@ -421,10 +419,10 @@ pub fn analyze(allocator: Allocator, text: []const u8, token_buffer: *Token.Buff
         });
         const line_offset = token_buffer.line_offsets.items[line_index];
         const column = start_index - line_offset;
-        logln(.lexer, .new_token, "T at line {}, column {}, byte offset {}, with length {} -line offset: {}- ({s})", .{line_index, column, start_index, token_length, line_offset, @tagName(token_id)});
+        logln(.lexer, .new_token, "T at line {}, column {}, byte offset {}, with length {} -line offset: {}- ({s})", .{ line_index, column, start_index, token_length, line_offset, @tagName(token_id) });
     }
 
-    logln(.lexer, .end, "END LEXER - TOKEN OFFSET: {} - LINE OFFSET: {}", .{Token.unwrap(lexer.offset), lexer.line_offset});
+    logln(.lexer, .end, "END LEXER - TOKEN OFFSET: {} - LINE OFFSET: {}", .{ Token.unwrap(lexer.offset), lexer.line_offset });
 
     lexer.count = Token.sub(token_buffer.getOffset(), lexer.offset);
     lexer.line_count = token_buffer.getLineOffset() - lexer.line_offset;

bootstrap/frontend/parser.zig

@@ -65,7 +65,7 @@ pub const Node = struct {
     token: Token.Index,
     id: Id,
 
-    pub const List = BlockList(@This(), enum{});
+    pub const List = BlockList(@This(), enum {});
     pub usingnamespace List.Index;
 
     pub const Range = struct {
@@ -187,6 +187,9 @@ pub const Node = struct {
         test_declaration,
         all_errors,
         error_union,
+        catch_expression,
+        try_expression,
+        error_type,
     };
 };
 
@@ -307,7 +310,9 @@ const Analyzer = struct {
                             if (equal(u8, identifier_name, enum_field.name)) {
                                 const attribute = @field(Compilation.Debug.Declaration.Global.Attribute, enum_field.name);
                                 const attribute_node = switch (attribute) {
-                                    .@"export", .@"extern", => try analyzer.addNode(.{
+                                    .@"export",
+                                    .@"extern",
+                                    => try analyzer.addNode(.{
                                         .id = @field(Node.Id, "symbol_attribute_" ++ @tagName(attribute)),
                                         .token = identifier,
                                         .left = .null,
@@ -393,7 +398,8 @@ const Analyzer = struct {
                 if (equal(u8, identifier_name, enum_field.name)) {
                     const attribute = @field(Compilation.Function.Attribute, enum_field.name);
                     const attribute_node = switch (attribute) {
-                        .naked, => try analyzer.addNode(.{
+                        .naked,
+                        => try analyzer.addNode(.{
                             .id = @field(Node.Id, "function_attribute_" ++ @tagName(attribute)),
                             .token = identifier,
                             .left = .null,
@@ -420,7 +426,7 @@ const Analyzer = struct {
             .id = .function_prototype,
             .token = token,
             .left = arguments,
-            .right = try analyzer.nodeList( attribute_and_return_type_node_list),
+            .right = try analyzer.nodeList(attribute_and_return_type_node_list),
         });
 
         return function_prototype;
@@ -473,16 +479,17 @@ const Analyzer = struct {
             const first_statement_token = analyzer.peekToken();
             logln(.parser, .block, "First statement token: {s}", .{@tagName(first_statement_token)});
             const statement_index = switch (first_statement_token) {
-                .identifier => switch (analyzer.peekTokenAhead(1)) {
+                else => try analyzer.assignExpressionStatement(),
-                    .operator_colon => {
+                // .identifier => switch (analyzer.peekTokenAhead(1)) {
-                        unreachable;
+                //     .operator_colon => {
-                    },
+                //         unreachable;
-                    else => try analyzer.assignExpressionStatement(),
+                //     },
-                },
+                //     else => try analyzer.assignExpressionStatement(),
-                .fixed_keyword_unreachable,
+                // },
-                .fixed_keyword_return,
+                // .fixed_keyword_unreachable,
-                .discard,
+                // .fixed_keyword_return,
-                => try analyzer.assignExpressionStatement(),
+                // .discard,
+                // => try analyzer.assignExpressionStatement(),
 
                 .fixed_keyword_while => try analyzer.whileExpression(),
                 .fixed_keyword_switch => try analyzer.switchExpression(),
@@ -491,17 +498,12 @@ const Analyzer = struct {
                 .fixed_keyword_const,
                 .fixed_keyword_var,
                 => try analyzer.symbolDeclaration(),
-                .fixed_keyword_break => b: {
+                // .intrinsic => blk: {
-                    const node_index = try analyzer.breakExpression();
+                //     const intrinsic = try analyzer.compilerIntrinsic();
-                    _ = try analyzer.expectToken(.operator_semicolon);
+                //     _ = try analyzer.expectToken(.operator_semicolon);
-                    break :b node_index;
+                //     break :blk intrinsic;
-                },
+                // },
-                .intrinsic => blk: {
+                // else => |t| @panic(@tagName(t)),
-                    const intrinsic = try analyzer.compilerIntrinsic();
-                    _ = try analyzer.expectToken(.operator_semicolon);
-                    break :blk intrinsic;
-                },
-                else => |t| @panic(@tagName(t)),
             };
 
             const node = analyzer.nodes.get(statement_index);
@@ -783,7 +785,7 @@ const Analyzer = struct {
         const left = try analyzer.expression();
         const expression_token = analyzer.token_i;
         const expression_id: Node.Id = switch (analyzer.peekToken()) {
-            .operator_semicolon, .operator_comma => return left,
+            .operator_semicolon, .operator_comma, .operator_right_brace, .identifier => return left,
             .operator_assign => .assign,
             .operator_add_assign => .add_assign,
             .operator_sub_assign => .sub_assign,
@@ -951,6 +953,7 @@ const Analyzer = struct {
         bit_or,
         shift_left,
         shift_right,
+        @"catch",
     };
 
     const operator_precedence = std.EnumArray(PrecedenceOperator, i32).init(.{
@@ -970,6 +973,7 @@ const Analyzer = struct {
         .bit_or = 40,
         .shift_left = 50,
         .shift_right = 50,
+        .@"catch" = 40,
     });
 
     const operator_associativity = std.EnumArray(PrecedenceOperator, Associativity).init(.{
@@ -989,6 +993,7 @@ const Analyzer = struct {
         .mod = .left,
         .shift_left = .left,
         .shift_right = .left,
+        .@"catch" = .left,
     });
 
     const operator_node_id = std.EnumArray(PrecedenceOperator, Node.Id).init(.{
@@ -1008,6 +1013,7 @@ const Analyzer = struct {
         .mod = .mod,
         .shift_left = .shift_left,
         .shift_right = .shift_right,
+        .@"catch" = .catch_expression,
     });
 
     fn expressionPrecedence(analyzer: *Analyzer, minimum_precedence: i32) !Node.Index {
@@ -1062,6 +1068,7 @@ const Analyzer = struct {
                 .operator_xor => .bit_xor,
                 .operator_shift_left => .shift_left,
                 .operator_shift_right => .shift_right,
+                .fixed_keyword_catch => .@"catch",
                 else => |t| @panic(@tagName(t)),
             };
 
@@ -1114,6 +1121,7 @@ const Analyzer = struct {
             },
             .operator_bang => .boolean_not,
             .operator_minus => .negation,
+            .fixed_keyword_try => .try_expression,
             // .tilde => |t| @panic(@tagName(t)),
         };
 
@@ -1155,6 +1163,9 @@ const Analyzer = struct {
             .discard,
             .fixed_keyword_undefined,
             .operator_left_bracket,
+            .fixed_keyword_const,
+            .fixed_keyword_var,
+            .fixed_keyword_error,
             => try analyzer.curlySuffixExpression(),
             .fixed_keyword_fn => try analyzer.function(),
             .fixed_keyword_return => try analyzer.addNode(.{
@@ -1167,6 +1178,7 @@ const Analyzer = struct {
                 .left = try analyzer.expression(),
                 .right = Node.Index.null,
             }),
+            .fixed_keyword_break => try analyzer.breakExpression(),
             // todo:?
             .operator_left_brace => try analyzer.block(),
             .fixed_keyword_if => try analyzer.ifExpression(),
@@ -1384,34 +1396,40 @@ const Analyzer = struct {
     }
 
     fn errorUnionExpression(analyzer: *Analyzer) !Node.Index {
-        if (analyzer.peekToken() == .operator_bang) {
+        const initial = analyzer.token_i;
-            const error_union_token = try analyzer.expectToken(.operator_bang);
+        if (analyzer.peekToken() == .operator_asterisk and analyzer.peekTokenAhead(1) == .operator_bang) {
-            if (analyzer.peekToken() == .operator_asterisk) {
+            const asterisk = try analyzer.expectToken(.operator_asterisk);
-                analyzer.consumeToken();
+            analyzer.consumeToken();
-                // All errors
+            const type_node = try analyzer.suffixExpression();
-                const all_errors_node = try analyzer.addNode(.{
-                    .id = .all_errors,
-                    .token = error_union_token,
-                    .left = .null,
-                    .right = .null,
-                });
-                const type_node = try analyzer.suffixExpression();
 
-                const error_union = try analyzer.addNode(.{
+            const all_errors_node = try analyzer.addNode(.{
-                    .id = .error_union,
+                .id = .all_errors,
-                    .token = error_union_token,
+                .token = asterisk,
-                    .left = all_errors_node,
+                .left = .null,
-                    .right = type_node,
+                .right = .null,
-                });
+            });
-                return error_union;
+
-            } else {
+            const error_union = try analyzer.addNode(.{
-                unreachable;
+                .id = .error_union,
-            }
+                .token = asterisk,
+                // All errors
+                .left = all_errors_node,
+                .right = type_node,
+            });
+            return error_union;
         } else {
             const suffix_expression = try analyzer.suffixExpression();
 
             return switch (analyzer.peekToken()) {
-                .operator_bang => unreachable,
+                .operator_bang => try analyzer.addNode(.{
+                    .id = .error_union,
+                    .token = blk: {
+                        analyzer.consumeToken();
+                        break :blk initial;
+                    },
+                    .left = suffix_expression,
+                    .right = try analyzer.typeExpression(),
+                }),
                 else => suffix_expression,
             };
         }
@@ -1598,8 +1616,9 @@ const Analyzer = struct {
         });
     }
 
-    fn processContainerType(analyzer: *Analyzer, maybe_token_id: ?Token.Id) !Node.Index{
+    fn processContainerType(analyzer: *Analyzer, maybe_token_id: ?Token.Id) !Node.Index {
         const token_i = if (maybe_token_id) |tid| try analyzer.expectToken(tid) else analyzer.token_i;
+        assert(Token.unwrap(analyzer.token_i) < analyzer.token_buffer.tokens.len);
         const token_id = maybe_token_id orelse .fixed_keyword_struct;
         const container_type: Compilation.ContainerType = switch (token_id) {
             .fixed_keyword_struct => .@"struct",
@@ -1608,8 +1627,8 @@ const Analyzer = struct {
         };
 
         const node_id: Node.Id = switch (token_id) {
-            .fixed_keyword_struct => .@"struct_type",
+            .fixed_keyword_struct => .struct_type,
-            .fixed_keyword_enum => .@"enum_type",
+            .fixed_keyword_enum => .enum_type,
             else => unreachable,
         };
 
@@ -1710,7 +1729,7 @@ const Analyzer = struct {
             const member_node = analyzer.nodes.get(member_node_index);
             if (member_node.id == .identifier) {
                 const token_offset = analyzer.getTokenOffset(member_node.token);
-                std.debug.print("Node index #{} (list index {}):\n```\n{s}\n```\n", .{Node.unwrap(member_node_index), index, analyzer.source_file[token_offset..]});
+                std.debug.print("Node index #{} (list index {}):\n```\n{s}\n```\n", .{ Node.unwrap(member_node_index), index, analyzer.source_file[token_offset..] });
                 // std.debug.print("ID: {s}\n", .{analyzer.bytes(member_node.token)});
                 unreachable;
             }
@@ -1726,7 +1745,16 @@ const Analyzer = struct {
 
     fn testDeclaration(analyzer: *Analyzer) !Node.Index {
         const test_token = try analyzer.expectToken(.fixed_keyword_test);
-        const name_node: Node.Index = if (analyzer.peekToken() == .string_literal) try analyzer.identifierNode() else .null;
+        const name_node: Node.Index = if (analyzer.peekToken() == .string_literal) try analyzer.addNode(.{
+            .id = .string_literal,
+            .token = b: {
+                const index = analyzer.token_i;
+                analyzer.consumeToken();
+                break :b index;
+            },
+            .left = .null,
+            .right = .null,
+        }) else .null;
         const test_block = try analyzer.block();
         return try analyzer.addNode(.{
             .token = test_token,
@@ -1861,6 +1889,33 @@ const Analyzer = struct {
                 _ = try analyzer.expectToken(.operator_right_parenthesis);
                 break :blk expr;
             },
+            .fixed_keyword_error => blk: {
+                analyzer.consumeToken();
+                if (analyzer.peekToken() == .operator_left_brace) {
+                    analyzer.consumeToken();
+                    var list = ArrayList(Node.Index){};
+
+                    while (analyzer.peekToken() != .operator_right_brace) {
+                        const identifier = try analyzer.identifierNode();
+                        try list.append(analyzer.allocator, identifier);
+                        const comma = try analyzer.expectToken(.operator_comma);
+                        _ = comma; // autofix
+                    }
+
+                    analyzer.consumeToken();
+
+                    break :blk try analyzer.addNode(.{
+                        .id = .error_type,
+                        .token = token_i,
+                        .left = try analyzer.nodeList(list),
+                        .right = .null,
+                    });
+                } else {
+                    const t = analyzer.peekToken();
+                    _ = t; // autofix
+                    unreachable;
+                }
+            },
             else => |t| switch (t) {
                 .identifier => std.debug.panic("{s}: {s}", .{ @tagName(t), analyzer.bytes(token_i) }),
                 else => @panic(@tagName(t)),
@@ -2031,7 +2086,6 @@ const Analyzer = struct {
     }
 };
 
-
 // Here it is assumed that left brace is consumed
 pub fn analyze(allocator: Allocator, lexer_result: lexer.Result, source_file: []const u8, token_buffer: *Token.Buffer, node_list: *Node.List, node_lists: *ArrayList(ArrayList(Node.Index))) !Result {
     const start = std.time.Instant.now() catch unreachable;
@@ -2065,5 +2119,3 @@ const Associativity = enum {
     none,
     left,
 };
-
-

lib/std/builtin.nat

@@ -30,5 +30,5 @@ const panic = fn (reason: PanicReason) noreturn{
 
 const TestFunction = struct{
     name: []const u8,
-    function: &const fn () !*void,
+    function: &const fn () *!void,
 };

lib/std/start.nat

@@ -31,8 +31,8 @@ const start :: export = fn (argc_argv_address: usize) noreturn {
     argument_address_iterator += #size(usize) * (argument_count + 1);
     environment_values = #cast(argument_address_iterator);
     const env = environment_values;
-    const result = #import("main").main();
+    #import("root").main() catch std.os.exit(1);
-    std.os.exit(exit_code = result);
+    std.os.exit(0);
 }
 
 const main :: export = fn (argc: s32, argv: [&]const [&:0]const u8, env: [&:null]const ?[&:null]const u8) s32 {
@@ -40,5 +40,6 @@ const main :: export = fn (argc: s32, argv: [&]const [&:0]const u8, env: [&:null
     argument_count = argc_u;
     argument_values = argv;
     environment_values = env;
-    return #import("main").main();
+    #import("root").main() catch return 1;
+    return 0;
 }

lib/test_runner.nat

@@ -0,0 +1,6 @@
+const builtin = #import("builtin");
+const main = fn () *!void {
+    for (builtin.test_functions) |test_function| {
+        try test_function.function();
+    }
+}

test/build/first/src/main.nat

@@ -1,3 +0,0 @@
-const main = fn () s32 {
-    return 0;
-}

test/build/first_build/build.nat

@@ -2,7 +2,11 @@ const std = #import("std");
 const assert = std.assert;
 const Executable = std.build.Executable;
 
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     const executable = Executable{
         .target = .{
             .cpu = .x86_64,
@@ -10,13 +14,12 @@ const main = fn () s32 {
             .abi = .gnu,
         },
         .main_source_path = "src/main.nat",
-        .name = "first",
+        .name = "first_build",
     };
 
     if (executable.compile()) {
-        return 0;
     } else {
         std.print(bytes = "Executable failed to compile!\n");
-        return 1;
+        return Error.unexpected_result;
     }
 }

test/build/first_build/src/main.nat

@@ -0,0 +1,2 @@
+const main = fn () *!void {
+}

test/build/link_libc/build.nat

@@ -2,7 +2,11 @@ const std = #import("std");
 const assert = std.assert;
 const Executable = std.build.Executable;
 
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     const executable = Executable{
         .target = .{
             .cpu = .x86_64,
@@ -15,9 +19,8 @@ const main = fn () s32 {
     };
 
     if (executable.compile()) {
-        return 0;
     } else {
         std.print(bytes = "Executable failed to compile!\n");
-        return 1;
+        return Error.unexpected_result;
     }
 }

test/build/link_libc/src/main.nat

@@ -1,3 +1,2 @@
-const main = fn () s32 {
+const main = fn () *!void {
-    return 0;
 }

test/standalone/add_sub/main.nat

@@ -1,8 +1,14 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     const a: s32 = 1;
     const b: s32 = 2;
     const c: s32 = a + b;
     const d: s32 = 3;
     const e: s32 = d - c;
-    return e;
+    if (e != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/and/main.nat

@@ -1,6 +1,11 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+const main = fn() Error!void {
     var a: s32 = 5;
     var b: s32 = 4;
     var result = a & b;
-    return result - b;
+    if (result - b != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/array_pointer_store/main.nat

@@ -1,10 +1,15 @@
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     const ch = 'a';
     var buffer: [1]u8 = undefined;
     var ptr: &[1]u8 = buffer.&;
     var index: usize = 0;
     ptr[index] = ch;
     const sub: u8 = ptr[index] - ch;
-    const result: u32 = sub;
+    if (sub != 0) {
-    return #cast(result);
+        return Error.unexpected_result;
+    }
 }

test/standalone/array_pointer_store_function/main.nat

@@ -1,4 +1,8 @@
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     var buffer: [2]u8 = undefined;
     const expected = 'a';
     const index: usize = 1;
@@ -6,7 +10,9 @@ const main = fn () s32 {
     const ch = buffer[index];
     const sub = expected - ch;
     const result: u32 = sub;
-    return #cast(result);
+    if (result != 0) {
+        return Error.unexpected_result;
+    }
 }
 
 const foo = fn (buffer: &[2]u8, index: usize, ch: u8) void {

test/standalone/array_store/main.nat

@@ -1,9 +1,13 @@
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     const ch = 'a';
     var buffer: [1]u8 = undefined;
     var index: usize = 0;
     buffer[index] = ch;
-    const sub: u8 = buffer[index] - ch;
+    if (buffer[index] - ch != 0) {
-    const result: u32 = sub;
+        return Error.unexpected_result;
-    return #cast(result);
+    }
 }

test/standalone/assert/main.nat

@@ -1,10 +1,9 @@
 const std = #import("std");
 const assert = std.assert;
 
-const main = fn() s32 {
+const main = fn() *!void {
     assert(true);
     var a: s32 = 1;
     const is_not_one = a != 1;
     assert(!is_not_one);
-    return 0;
 }

test/standalone/bit_struct/main.nat

@@ -8,7 +8,7 @@ const BitStruct = struct(u8) {
     d: u5,
 };
 
-const main = fn () s32 {
+const main = fn () *!void {
     var bs = BitStruct{
         .a = false,
         .b = true,
@@ -26,5 +26,4 @@ const main = fn () s32 {
     };
     const bitcast_const_bs: u8 = #cast(const_bs);
     assert(bitcast_const_bs == 5);
-    return 0;
 }

test/standalone/bit_struct_call/main.nat

@@ -17,7 +17,7 @@ const transform = fn (a: A) B {
     };
 }
 
-const main = fn () s32 {
+const main = fn () *!void {
     var a = A{
         .a = 3,
         .b = 8,
@@ -26,6 +26,4 @@ const main = fn () s32 {
     const b = transform(a);
     assert(a.a == b.a);
     assert(a.b == b.b);
-
-    return 0;
 }

test/standalone/break/main.nat

@@ -1,4 +1,7 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+const main = fn() Error!void {
     var i: s32 = 0;
     const j: s32 = 5;
     for (0..10) |_| {
@@ -8,5 +11,7 @@ const main = fn() s32 {
         i += 1;
     }
 
-    return i - j;
+    if (i - j != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/conditional_compilation_basic/main.nat

@@ -1,7 +1,10 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     if (true) {
-        return 0;
     } else {
-        return 1;
+        return Error.unexpected_result;
     }
 }

test/standalone/div/main.nat

@@ -1,8 +1,13 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+const main = fn() Error!void {
     const dividend: s32 = 30;
     const divisor: s32 = 6;
     const div: s32 = dividend / divisor;
     const n: s32 = 5;
 
-    return n - div;
+    if (n - div != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/else_if/main.nat

@@ -1,13 +1,20 @@
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     const a = foo(5);
     if (a != 123) {
-        return 1;
+        return Error.unexpected_result;
     }
     const b = foo(5);
     if (b != 123) {
-        return 1;
+        return Error.unexpected_result;
+    }
+
+    if (a - b != 0) {
+        return Error.unexpected_result;
     }
-    return a - b;
 }
 
 const foo = fn (arg: s32) s32 {

test/standalone/first/main.nat

@@ -1,3 +1 @@
-const main = fn() s32 {
+const main = fn() *!void { }
-    return 0;
-}

test/standalone/foreach/main.nat

@@ -1,4 +1,8 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     var counter: s32 = 0;
     const loop = 10;
 
@@ -6,5 +10,7 @@ const main = fn() s32 {
         counter += 1;
     }
 
-    return loop - counter;
+    if (loop - counter != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/foreach_slice/main.nat

@@ -20,12 +20,17 @@ const print_values = fn(slice: []const u8) void {
     }
 }
 
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     const a = [_]u8{1, 1, 4, 5, 6};
     const b = [_]u8{1, 4, 6};
     const expected_result: usize = a.len + b.len;
     const result = count_slice_byte_count(slices = .{a.&, b.&}.&);
     print_values(slice = a.&);
-    const main_result: u32 = #cast(expected_result - result);
+    if (expected_result - result != 0) {
-    return #cast(main_result);
+        return Error.unexpected_result;
+    }
 }

test/standalone/fork/main.nat

@@ -1,16 +1,18 @@
+const Error = error{
+    unexpected_result,
+};
 const std = #import("std");
 
-const main = fn() s32 {
+const main = fn() Error!void {
     if (std.os.duplicate_process()) |pid| {
         if (pid == 0) {
             std.print(bytes = "Hello from child\n");
             std.os.exit(exit_code = 0);
         } else {
             std.print(bytes = "Hello from parent\n");
-            return 0;
         }
     } else {
         std.print(bytes = "Unable to create child process\n");
-        return 1;
+        return Error.unexpected_result;
     }
 }

test/standalone/fork_exec/main.nat

@@ -1,18 +1,21 @@
 const std = #import("std");
 
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     if (std.os.duplicate_process()) |pid| {
         if (pid == 0) {
             std.print(bytes = "Hello from child\n");
             const argv = [_:null] ?[&:0]const u8{"/usr/bin/ls"};
             _ = std.os.execute(path = "/usr/bin/ls", argv = argv.&, env = std.start.environment_values);
-            return 1;
+            return Error.unexpected_result;
         } else {
             std.print(bytes = "Hello from parent\n");
-            return 0;
         }
     } else {
         std.print(bytes = "Unable to create child process\n");
-        return 1;
+        return Error.unexpected_result;
     }
 }

test/standalone/function_pointer/main.nat

@@ -4,8 +4,14 @@ const foo = fn () s32 {
     return expected_number;
 }
 
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     var function_pointer = foo.&;
     const result = function_pointer();
-    return result - expected_number;
+    if (result - expected_number != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/function_pointer_struct/main.nat

@@ -13,11 +13,17 @@ const Struct = struct{
     }
 };
 
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     var s = Struct{
         .a = expected_number,
         .handler = Struct.handler_function.&,
     };
 
-    return s.handler(s.&) - expected_number;
+    if (s.handler(s.&) - expected_number != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/hello_world/main.nat

@@ -1,6 +1,5 @@
 const std = #import("std");
 
-const main = fn() s32 {
+const main = fn() *!void {
     std.print(bytes = "Hello world!\n");
-    return 0;
 }

test/standalone/if/main.nat

@@ -1,13 +1,18 @@
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+const main = fn () Error!void {
     const a = foo(5);
     if (a != 6) {
-        return 1;
+        return Error.unexpected_result;
     }
     const b = foo(5);
     if (b != 6) {
-        return 1;
+        return Error.unexpected_result;
+    }
+    if (a - b != 0) {
+        return Error.unexpected_result;
     }
-    return a - b;
 }
 
 const foo = fn (arg: s32) s32 {

test/standalone/if_not_else/main.nat

@@ -1,13 +1,20 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     const a = foo(5);
     if (a != 12412) {
-        return 1;
+        return Error.unexpected_result;
     }
     const b = foo(5);
     if (b != 12412) {
-        return 1;
+        return Error.unexpected_result;
+    }
+    
+    if (a - b != 0) {
+        return Error.unexpected_result;
     }
-    return a - b;
 }
 
 const foo = fn(arg: s32) s32 {

test/standalone/imul/main.nat

@@ -1,5 +1,10 @@
-const main = fn() s32 {
+const Error = error{
-    const a: s32 = 5;
+    unexpected_result,
-    const b: s32 = 4;
+};
-    return a * b - a * b;
+const main = fn() Error!void {
+    var a: s32 = 5;
+    var b: s32 = 4;
+    if (a * b - a * b != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/loop_break/main.nat

@@ -1,4 +1,8 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     var i: s32 = 0;
     while (i < 10) {
         i += 1;
@@ -7,5 +11,7 @@ const main = fn() s32 {
         }
     }
 
-    return i - 5;
+    if (i - 5 != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/loop_return/main.nat

@@ -1,13 +1,19 @@
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     const a = foo(5142);
     if (a != 2501) {
-        return 1;
+        return Error.unexpected_result;
     }
     const b = foo(5142);
     if (b != 2501) {
-        return 1;
+        return Error.unexpected_result;
+    }
+    if (a - b != 0) {
+        return Error.unexpected_result;
     }
-    return #cast(a - b);
 }
 
 const foo = fn (arg: u32) u32 {

test/standalone/loop_return_only_else/main.nat

@@ -1,7 +1,12 @@
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+const main = fn () Error!void {
     const a = foo(5142);
     const b = foo(5142);
-    return #cast(a - b);
+    if (a - b != 0) {
+        return Error.unexpected_result;
+    }
 }
 
 const foo = fn (arg: u32) u32 {

test/standalone/nested_if/main.nat

@@ -1,7 +1,13 @@
-const main = fn () s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     const a = foo(5);
     const b = foo(5);
-    return a - b;
+    if (a - b != 0) {
+        return Error.unexpected_result;
+    }
 }
 
 const foo = fn (arg: s32) s32 {

test/standalone/null_terminated/main.nat

@@ -1,7 +1,6 @@
 const std = #import("std");
 const assert = std.assert;
-const main = fn() s32 {
+const main = fn() *!void {
     var foo = [2:null] ?[&:0]const u8 {"Hi", "Ho"};
     assert(foo[2] == null);
-    return 0;
 }

test/standalone/optional_wrap/main.nat

@@ -1,8 +1,6 @@
 const foo = fn(slice: []u8) ?[]u8 {
     return slice[0..1];
 }
-const main = fn() s32 {
+const main = fn() *!void {
     _ = foo(slice = .{ 0, 1, 2, 3 }.&);
-
-    return 0;
 }

test/standalone/or/main.nat

@@ -1,7 +1,13 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     const a: u32 = 0xffff;
     const b: u32 = 0xffff0000;
     const c: u32 = 0xffffffff;
     const result = c - (a | b);
-    return #cast(result);
+    if (result != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/self_exe_path/main.nat

@@ -1,14 +1,16 @@
 const std = #import("std");
 const print = std.print;
 
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     var buffer: [std.os.max_path_byte_count:0]u8 = undefined;
     if (std.os.current_executable_path(buffer = buffer.&)) |bytes| {
         print(bytes);
         print(bytes = "\n");
-        return 0;
     } else {
-        print(bytes = "Failed\n");
+        return Error.unexpected_result;
-        return 1;
     }
 }

test/standalone/shifts/main.nat

@@ -1,7 +1,13 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     var x: u32 = 1;
     x = x << 5;
     x = x >> 5;
     const b: u32 = 1;
-    return #cast(x - b);
+    if (x - b != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/simple_bool/main.nat

@@ -1,8 +1,10 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     var false_boolean: bool = false;
     if (false_boolean) {
-        return 1;
+        return Error.unexpected_result;
-    } else {
-        return 0;
     }
 }

test/standalone/size/main.nat

@@ -1,6 +1,9 @@
-const std = #import("std");
+const Error = error{
-const assert = std.assert;
+    unexpected_result,
-const main = fn () s32 {
+};
-    assert(#size(usize) == 8);
+
-    return 0;
+const main = fn () Error!void {
+    if (#size(usize) != 8) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/slice/main.nat

@@ -1,4 +1,8 @@
-const main = fn () s32{
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void{
     const a: [4]u8 = .{1, 2, 3, 4};
     const b: []const []const u8 = .{a.&}.&;
 
@@ -10,5 +14,7 @@ const main = fn () s32{
         }
     }
 
-    return #cast(sum - 10);
+    if (sum - 10 != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/slice2/main.nat

@@ -1,7 +1,12 @@
-const main = fn () s32{
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn () Error!void {
     const a: [4]u8 = .{1, 2, 3, 4};
     const b: []const []const u8 = .{a.&}.&;
     const c: u8 = b[0][0] - 1;
-    const d: u32 = c;
+    if (c != 0) {
-    return #cast(c);
+        return Error.unexpected_result;
+    }
 }

test/standalone/slice_expression/main.nat

@@ -1,6 +1,5 @@
-const main = fn () s32 {
+const main = fn () *!void {
     _ = foo();
-    return 0;
 }
 
 const foo = fn () []u8 {

test/standalone/slice_len/main.nat

@@ -1,12 +1,18 @@
 const std = #import("std");
 const assert = std.assert;
 
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     var buffer: [65]u8 = undefined;
     const slice = foo(5, buffer.&);
     assert(slice.len + 5 == buffer.len);
     const result: u32 = #cast(slice.len + 5 - buffer.len);
-    return #cast(result);
+    if (result != 0) {
+        return Error.unexpected_result;
+    }
 }
 const foo = fn(n: usize, buffer: &[65]u8) []u8 {
     return buffer[n..];

test/standalone/stack/main.nat

@@ -1,4 +1,9 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+const main = fn() Error!void {
     var a : s32 = 0;
-    return a;
+    if (a != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/virtual_memory/main.nat

@@ -1,6 +1,10 @@
 const std = #import("std");
 
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     const size = 0x1000;
 
     if (std.page_allocator.allocate(size, alignment = 12)) |result| {
@@ -8,13 +12,12 @@ const main = fn() s32 {
         std.print(bytes = "Allocation succeeded. Freeing...\n");
         if (std.page_allocator.free(bytes_ptr = result.ptr, bytes_len = result.len)) {
             std.print(bytes = "Memory freed successfully\n");
-            return 0;
         } else {
             std.print(bytes = "Memory freed with errors\n");
-            return 1;
+            return Error.unexpected_result;
         }
     } else {
         std.print(bytes = "Allocation failed!\n");
-        return 1;
+        return Error.unexpected_result;
     }
 }

test/standalone/xor/main.nat

@@ -1,7 +1,13 @@
-const main = fn() s32 {
+const Error = error{
+    unexpected_result,
+};
+
+const main = fn() Error!void {
     var a: s32 = 561;
     var b: s32 = 124;
     var c: s32 = a ^ b;
     var d: s32 = a ^ b;
-    return c ^ d;
+    if (c ^ d != 0) {
+        return Error.unexpected_result;
+    }
 }

test/standalone/zero_terminated/main.nat

@@ -1,7 +1,6 @@
 const std = #import("std");
 const assert = std.assert;
-const main = fn () s32 {
+const main = fn () *!void {
     var a = [2:0]u8 {1, 2};
     assert(a[2] == 0);
-    return 0;
 }

test/tests/first_test/main.nat

@@ -0,0 +1,2 @@
+test "First test" {
+}

test/tests/main.nat

@@ -1,2 +0,0 @@
-test {
-}