unsigned integer constraint (uint)

LANGUAGE.md

@@ -24,7 +24,7 @@ roadmap and milestone history.
 
 ### scalar, aggregate, and pointer types
 
-- exact-width integers, `isize`, `usize`, `f32`, `f64`, `bool`, `void`, `anyopaque`, and contextual `int`, `float`, and `range` constraints
+- exact-width integers, concrete pointer-sized `isize` / `usize`, `f32`, `f64`, `bool`, `void`, and `anyopaque`; contextual `int` accepts the whole integer family, while `uint` accepts only unsigned native and target-classified C integers
 - target-dependent C scalar primitives from `c_char` through `c_longdouble`, kept semantically distinct from native scalars
 - contextual integer/float/character literals, backward type-demand inference through names and arithmetic, and compile-time folding for numeric constant expressions
 - strict numeric conversion by default, widening where valid, C scalar coercions at C boundaries, and explicit scalar keyword casts such as `i32(x)` / `c_float(x)`
@@ -44,16 +44,17 @@ roadmap and milestone history.
 
 #### native record constraint fields
 
-A direct `int`, `float`, or `range` field in a named native struct or union is a
+A direct `int`, `uint`, `float`, or `range` field in a named native struct or union is a
 program-wide constraint, not per-value polymorphism. Before record layout, all reachable keyed
 constructors, field assignments, and concrete uses of field reads contribute demands and the field
 resolves once to one concrete runtime type. Compatible scalar demands widen normally. Integer
 literals remain provisional until inference settles, so a later `usize` use can resolve an `int`
 field to `usize`; otherwise literal-only `int` fields use the widest smallest-signed type required,
-and literal-only `float` fields use `f64`.
+literal-only `uint` fields use the widest smallest-unsigned type required, and literal-only `float`
+fields use `f64`.
 
 An undemanded field or incompatible demands are errors. This inference applies only to direct
-fields of named native records. `c_struct` fields, nested constraints such as `[]int`, and fields in
+fields of named native records. `c_struct` fields, nested constraints such as `[]int` / `[]uint`, and fields in
 anonymous generated records still require concrete runtime types.
 
 #### keyword member names

TODO.md

@@ -907,6 +907,12 @@
   - filtering, skipping, fixtures, snapshots, parallelism, isolation, allocators, and more assertion
     families remain deferred
 
+42. unsigned integer constraint (implemented)
+  - `uint` is the unsigned subset constraint while `int` remains the whole integer family
+  - literal-only values choose the smallest fitting `u8`, `u16`, `u32`, or `u64`
+  - native unsigned scalars and target-classified unsigned C scalars satisfy the constraint
+  - `isize` and `usize` remain concrete pointer-sized types
+
 ## A word on unchecked casts
 
 For casts that bypass safety checks, Honey provides builtin functions:

compiler/checker/checker.odin

@@ -501,7 +501,7 @@ write_type_label :: proc(checker: ^Checker, builder: ^strings.Builder, value: ty
 		strings.write_string(builder, "enum")
 	case .Alias, .Distinct, .Named:
 		write_type_label(checker, builder, item.child)
-	case .Invalid, .Void, .Anyopaque, .Int_Constraint, .Float_Constraint, .Range_Constraint, .Scalar:
+	case .Invalid, .Void, .Anyopaque, .Int_Constraint, .Uint_Constraint, .Float_Constraint, .Range_Constraint, .Scalar:
 		strings.write_string(builder, types.name(value))
 	}
 }
@@ -1052,6 +1052,26 @@ fits_i64 :: proc(value: i128) -> bool {
 	return fits_signed_type(value, types.I64)
 }
 
+fits_u64 :: proc(value: i128) -> bool {
+	return value >= 0 && value <= i128(0xffff_ffff_ffff_ffff)
+}
+
+constraint_integer_literal_type :: proc(constraint: types.Type, value: i128) -> types.Type {
+	if constraint == types.UINT {
+		return types.smallest_unsigned_for_literal(u64(value)) if fits_u64(value) else types.INVALID
+	}
+	return types.smallest_signed_for_literal(i64(value)) if fits_i64(value) else types.INVALID
+}
+
+constraint_recovery_type :: proc(checker: ^Checker, constraint: types.Type) -> types.Type {
+	switch constraint {
+	case types.UINT:  return types.U64
+	case types.FLOAT: return types.F64
+	case types.RANGE: return types.range(&checker.module.types, types.I64)
+	case:             return types.I64
+	}
+}
+
 type_from_syntax :: proc(
 	checker: ^Checker,
 	value: ast.Type_Syntax,
@@ -2647,7 +2667,7 @@ call_arg_expected :: proc(checker: ^Checker, function: ast.Function, index: int)
 	declared := type_from_syntax(checker, function.params[index].type, function.pkg, function.file)
 	// A `float` param defaults to f64 so an integer-literal argument builds as a
 	// float constant (e.g. `f(3)` -> 3.0), mirroring `pi float = 3` for locals.
-	// `int`/`range` constraints have no single default and keep building naturally.
+	// Integer/range constraints keep building naturally from their literals.
 	if declared == types.FLOAT {
 		return types.F64
 	}
@@ -3624,13 +3644,21 @@ record_field_expr_candidate :: proc(
 	}
 	expr := checker.ast_module.exprs[expr_id]
 	constraint := checker.record_field_constraints[slot]
-	if constant := eval_integer_constant_in_context(checker, expr_id, pkg, file);
+	if !numeric_operand_is_open(checker, expr_id, locals, pkg, file) {
-	   constant.kind == .Value && fits_i64(constant.value) {
+		concrete := types.constraint_target(constraint, inferred, &checker.module.types)
-		candidate := types.smallest_signed_for_literal(i64(constant.value))
+		if is_runtime_type(checker, concrete) {
-		if constraint == types.FLOAT {
+			return merge_record_field_demand(checker, slot, concrete, expr.span)
-			candidate = types.F64
+		}
+	}
+	if constant := eval_integer_constant_in_context(checker, expr_id, pkg, file);
+	   constant.kind == .Value {
+		candidate := constraint_integer_literal_type(constraint, constant.value)
+		if constraint == types.FLOAT {
+			candidate = types.F64 if fits_i64(constant.value) else types.INVALID
+		}
+		if types.is_valid(candidate) {
+			return merge_record_field_default(checker, slot, candidate, expr.span)
 		}
-		return merge_record_field_default(checker, slot, candidate, expr.span)
 	}
 	if is_float_constant_expr(checker, expr_id) {
 		return merge_record_field_default(checker, slot, types.F64, expr.span)
@@ -3693,14 +3721,7 @@ finalize_record_field_inference :: proc(checker: ^Checker) {
 			)
 		}
 		if types.is_constraint(current) {
-			switch constraint {
+			checker.module.types.fields[slot].type = constraint_recovery_type(checker, constraint)
-			case types.INT:
-				checker.module.types.fields[slot].type = types.I64
-			case types.FLOAT:
-				checker.module.types.fields[slot].type = types.F64
-			case types.RANGE:
-				checker.module.types.fields[slot].type = types.range(&checker.module.types, types.I64)
-			}
 		}
 	}
 }
@@ -3999,7 +4020,7 @@ find_spec :: proc(
 }
 
 // specialized_param_type maps a parameter's declared type to its monomorphized
-// type for a given actual argument. A constraint param (`int`/`float`/`range`)
+// type for a given actual argument. A constraint param (`int`/`uint`/`float`/`range`)
 // resolves to the actual's family member (INVALID if out of family), so a call
 // passing an out-of-family argument fails to specialize and is rejected.
 specialized_param_type :: proc(
@@ -4426,14 +4447,16 @@ infer_expr :: proc(
 			if expr.kind != .Name || symbol.is_valid(expr.qualifier) || !static_name {
 				constant = eval_constant(checker, frame.expr)
 			}
-			if constant.kind == .Overflow || constant.kind == .Div_By_Zero ||
+			if constant.kind == .Overflow || constant.kind == .Div_By_Zero {
-			   (constant.kind == .Value && !fits_i64(constant.value)) {
 				last = types.I64
 				_ = pop(&stack)
 				continue
 			}
 			if constant.kind == .Value {
-				last = types.smallest_signed_for_literal(i64(constant.value))
+				last = constraint_integer_literal_type(frame.expected, constant.value)
+				if !types.is_valid(last) {
+					last = types.I64
+				}
 				_ = pop(&stack)
 				continue
 			}
@@ -5066,7 +5089,7 @@ infer_statements :: proc(
 			declared_local := resolve_inferred_array(checker, type_from_syntax(checker, statement.type, pkg, file), statement.expr)
 			value_type := types.INVALID
 			if !is_undefined_expr(checker, statement.expr) {
-				expected := declared_local if is_runtime_type(checker, declared_local) else types.INVALID
+				expected := declared_local if is_runtime_type(checker, declared_local) || declared_local == types.UINT else types.INVALID
 				value_type = infer_expr(checker, statement.expr, locals^[:], pkg, file, demanded, local_types, expected)
 				declared_local = resolve_inferred_array_from_type(checker, declared_local, value_type)
 			}
@@ -5082,7 +5105,8 @@ infer_statements :: proc(
 			const_val := i128(0)
 			if !is_runtime_type(checker, declared_local) && !is_undefined_expr(checker, statement.expr) {
 				constant := eval_integer_constant_in_context(checker, statement.expr, pkg, file)
-				if constant.kind == .Value && fits_i64(constant.value) {
+				if constant.kind == .Value &&
+				   (fits_i64(constant.value) || declared_local == types.UINT && fits_u64(constant.value)) {
 					open = true
 					const_val = constant.value
 				} else if is_float_constant_expr(checker, statement.expr) {
@@ -5123,11 +5147,25 @@ infer_statements :: proc(
 			expected_assignment := types.INVALID
 			if statement.target != ast.INVALID_EXPR {
 				expected_assignment = infer_expr(checker, statement.target, locals^[:], pkg, file, demanded, local_types)
+				target_expr := checker.ast_module.exprs[statement.target]
+				if target_expr.kind == .Name && !symbol.is_valid(target_expr.qualifier) {
+					if local_index, ok := find_infer_local_index(locals^[:], target_expr.name); ok &&
+					   locals^[local_index].declared == types.UINT {
+						expected_assignment = types.UINT
+					} else if global := find_global(checker, target_expr.name, pkg, file); global != ast.INVALID_GLOBAL {
+						ast_global := checker.ast_module.globals[global]
+						if type_from_syntax(checker, ast_global.type, ast_global.pkg, ast_global.file) == types.UINT {
+							expected_assignment = types.UINT
+						}
+					}
+				}
 			} else if statement.name != checker.sink_symbol {
 				if local_index, ok := find_infer_local_index(locals^[:], statement.name); ok {
-					expected_assignment = locals^[local_index].type
+					expected_assignment = types.UINT if locals^[local_index].declared == types.UINT else locals^[local_index].type
 				} else if global := find_global(checker, statement.name, pkg, file); global != ast.INVALID_GLOBAL {
-					expected_assignment = checker.global_types[global]
+					ast_global := checker.ast_module.globals[global]
+					declared_global := type_from_syntax(checker, ast_global.type, ast_global.pkg, ast_global.file)
+					expected_assignment = types.UINT if declared_global == types.UINT else checker.global_types[global]
 				}
 			}
 			value_type := infer_expr(checker, statement.expr, locals^[:], pkg, file, demanded, local_types, expected_assignment)
@@ -5430,7 +5468,7 @@ infer_spec_locals_and_result :: proc(
 	if function.pkg == 0 && function.name == checker.main_symbol && function.result == types.INT {
 		declared = types.I32
 	}
-	result_hint := declared if is_runtime_type(checker, declared) else types.INVALID
+	result_hint := declared if is_runtime_type(checker, declared) || declared == types.UINT else types.INVALID
 
 	locals: [dynamic]Infer_Local
 	locals.allocator = checker.allocator
@@ -5615,7 +5653,7 @@ open_const_default_type :: proc(
 		if index, ok := find_infer_local_index(locals, expr.name); ok {
 			local := locals[index]
 			if local.open_const {
-				return types.smallest_signed_for_literal(i64(local.const_value))
+				return constraint_integer_literal_type(local.declared, local.const_value)
 			}
 			if local.open_float {
 				return types.F64
@@ -5633,7 +5671,9 @@ open_const_default_type :: proc(
 		return types.INVALID
 	}
 	if checker.global_open_const[index] {
-		return types.smallest_signed_for_literal(i64(checker.global_const_value[index]))
+		ast_global := checker.ast_module.globals[global]
+		declared := type_from_syntax(checker, ast_global.type, ast_global.pkg, ast_global.file)
+		return constraint_integer_literal_type(declared, checker.global_const_value[index])
 	}
 	if checker.global_open_float[index] {
 		return types.F64
@@ -5899,7 +5939,8 @@ infer_all :: proc(checker: ^Checker) {
 			}
 		}
 		constant := eval_integer_constant_in_context(checker, global.expr, global.pkg, global.file)
-		if constant.kind == .Value && fits_i64(constant.value) {
+		if constant.kind == .Value &&
+		   (fits_i64(constant.value) || declared == types.UINT && fits_u64(constant.value)) {
 			checker.global_open_const[index] = true
 			checker.global_const_value[index] = constant.value
 		} else if is_float_constant_expr(checker, global.expr) {
@@ -5947,7 +5988,7 @@ infer_all :: proc(checker: ^Checker) {
 				type_from_syntax(checker, global.type, global.pkg, global.file),
 				global.expr,
 			)
-			expected := declared if is_runtime_type(checker, declared) else types.INVALID
+			expected := declared if is_runtime_type(checker, declared) || declared == types.UINT else types.INVALID
 			inferred := infer_expr(checker, global.expr, nil, global.pkg, global.file, expected=expected)
 			if resolved := resolve_inferred_array_from_type(checker, declared, inferred);
 			   resolved != declared {
@@ -6020,7 +6061,8 @@ infer_all :: proc(checker: ^Checker) {
 						continue
 					}
 					if checker.global_open_const[index] {
-						checker.global_types[index] = types.smallest_signed_for_literal(i64(checker.global_const_value[index]))
+						declared := type_from_syntax(checker, global.type, global.pkg, global.file)
+						checker.global_types[index] = constraint_integer_literal_type(declared, checker.global_const_value[index])
 						defaulted = true
 					} else if checker.global_open_float[index] {
 						checker.global_types[index] = types.F64
@@ -6394,7 +6436,7 @@ build_constant_expr :: proc(
 		return invalid_hir_expr(checker, expr.span, id, recovery_type)
 	}
 	if constant.kind == .Overflow ||
-	   (!types.is_concrete_integer(expected) && !fits_i64(constant.value)) {
+	   (!types.is_concrete_integer(expected) && expected != types.UINT && !fits_i64(constant.value)) {
 		id := source.add(
 			checker.diagnostics,
 			expr.span,
@@ -6407,7 +6449,16 @@ build_constant_expr :: proc(
 	if constant.value >= 0 && constant.value <= i128(0xffff_ffff_ffff_ffff) {
 		value = transmute(i64)u64(constant.value)
 	}
-	result_type := types.smallest_signed_for_literal(value)
+	result_type := constraint_integer_literal_type(expected, constant.value)
+	if expected == types.UINT && !types.is_valid(result_type) {
+		id := source.addf(
+			checker.diagnostics,
+			expr.span,
+			"integer constant %d does not satisfy uint",
+			constant.value,
+		)
+		return invalid_hir_expr(checker, expr.span, id, types.U64)
+	}
 	if types.is_concrete_integer(expected) {
 		if !fits_integer_type(constant.value, expected, checker.target) {
 			id := source.addf(
@@ -12375,11 +12426,12 @@ build_globals :: proc(checker: ^Checker) {
 		if is_runtime_type(checker, declared) {
 			expected = declared
 		} else if constant := eval_integer_constant_in_context(checker, global.expr, global.pkg, global.file);
-		   constant.kind == .Value && fits_i64(constant.value) &&
+		   constant.kind == .Value &&
+		   (fits_i64(constant.value) || declared == types.UINT && fits_u64(constant.value)) &&
 		   is_runtime_type(checker, checker.global_types[global_index]) {
 			// Open integer constant: build against its demanded/defaulted type. Gated
 			// to the infer-side open-constant condition so out-of-range constants keep
-			// their original "exceeds signed i64 range" diagnostic.
+			// their original range diagnostic.
 			expected = checker.global_types[global_index]
 		} else if (is_float_constant_expr(checker, global.expr) ||
 		           is_numeric_arithmetic_expr(checker, global.expr)) &&
@@ -12401,6 +12453,18 @@ build_globals :: proc(checker: ^Checker) {
 				global_type = types.I64
 			}
 		}
+		if diagnostic == source.INVALID_DIAGNOSTIC && types.is_constraint(declared) &&
+		   !types.constraint_accepts(declared, global_type, &checker.module.types) {
+			diagnostic = source.addf(
+				checker.diagnostics,
+				global.span,
+				"could not resolve the '%s' constraint for global '%s'",
+				types.name(declared),
+				symbol_text(checker, global.name),
+			)
+			global_type = constraint_recovery_type(checker, declared)
+			expr = invalid_hir_expr(checker, global.span, diagnostic, global_type)
+		}
 		if !global.immutable && is_undefined_expr(checker, global.expr) {
 			diagnostic = source.add(
 				checker.diagnostics,

compiler/lexer/lexer.odin

@@ -52,6 +52,7 @@ keyword_kind :: proc(text: string) -> token.Kind {
 	case "anyopaque":     return .Keyword_Anyopaque
 	case "bool":          return .Keyword_Bool
 	case "int":           return .Keyword_Int
+	case "uint":          return .Keyword_Uint
 	case "float":         return .Keyword_Float
 	case "range":         return .Keyword_Range
 	case "i8":            return .Keyword_I8

compiler/parser/parser.odin

@@ -146,7 +146,7 @@ invalid_expr :: proc(parser: ^Parser, span: source.Span, message: string) -> ast
 
 is_type_token :: proc(kind: token.Kind) -> bool {
 	#partial switch kind {
-	case .Keyword_Int, .Keyword_Float, .Keyword_Range, .Keyword_I8, .Keyword_I16, .Keyword_I32, .Keyword_I64,
+	case .Keyword_Int, .Keyword_Uint, .Keyword_Float, .Keyword_Range, .Keyword_I8, .Keyword_I16, .Keyword_I32, .Keyword_I64,
 	     .Keyword_U8, .Keyword_U16, .Keyword_U32, .Keyword_U64,
 	     .Keyword_Isize, .Keyword_Usize, .Keyword_F32, .Keyword_F64,
 	     .Keyword_C_Char, .Keyword_C_Schar, .Keyword_C_Uchar,
@@ -280,6 +280,9 @@ parse_type_atom :: proc(parser: ^Parser) -> ast.Type_Syntax {
 	case .Keyword_Int:
 		advance(parser)
 		return types.INT
+	case .Keyword_Uint:
+		advance(parser)
+		return types.UINT
 	case .Keyword_Float:
 		advance(parser)
 		return types.FLOAT
@@ -774,7 +777,7 @@ parse_integer_magnitude :: proc(text: string) -> (u64, bool) {
 parse_primary :: proc(parser: ^Parser, nesting: int) -> ast.Expr_Id {
 	tok := current(parser)
 	#partial switch tok.kind {
-	case .Keyword_Int, .Keyword_Float, .Keyword_Range, .Keyword_Void, .Keyword_Anyopaque, .Keyword_Bool:
+	case .Keyword_Int, .Keyword_Uint, .Keyword_Float, .Keyword_Range, .Keyword_Void, .Keyword_Anyopaque, .Keyword_Bool:
 		start := tok
 		target := parse_type_atom(parser)
 		return add_expr(parser, ast.Expr{

compiler/token/token.odin

@@ -88,6 +88,7 @@ Kind :: enum u8 {
 	Keyword_Anyopaque,
 	Keyword_Bool,
 	Keyword_Int,
+	Keyword_Uint,
 	Keyword_Float,
 	Keyword_Range,
 	Keyword_I8,

compiler/types/types.odin

@@ -44,6 +44,7 @@ BOOL :: Type(29)
 FLOAT :: Type(30)
 RANGE :: Type(31)
 ANYOPAQUE :: Type(32)
+UINT :: Type(33)
 
 DYNAMIC_START :: Type(64)
 
@@ -59,6 +60,7 @@ Kind :: enum u8 {
 	Void,
 	Anyopaque,
 	Int_Constraint,
+	Uint_Constraint,
 	Float_Constraint,
 	Range_Constraint,
 	Scalar,
@@ -595,6 +597,8 @@ kind :: proc(value: Type, store: ^Store = nil) -> Kind {
 		return .Anyopaque
 	case INT:
 		return .Int_Constraint
+	case UINT:
+		return .Uint_Constraint
 	case FLOAT:
 		return .Float_Constraint
 	case RANGE:
@@ -642,7 +646,7 @@ is_bool :: proc(value: Type) -> bool {
 }
 
 is_constraint :: proc(value: Type) -> bool {
-	return value == INT || value == FLOAT || value == RANGE
+	return value == INT || value == UINT || value == FLOAT || value == RANGE
 }
 
 // constraint_target reports the concrete type a constraint binding (local, or a
@@ -656,6 +660,8 @@ constraint_target :: proc(constraint, inferred: Type, store: ^Store = nil) -> Ty
 	switch constraint {
 	case INT:
 		return inferred if is_concrete_integer(inferred) else INVALID
+	case UINT:
+		return inferred if is_unsigned(inferred) else INVALID
 	case FLOAT:
 		if is_float(inferred) {
 			return inferred
@@ -673,6 +679,8 @@ constraint_accepts :: proc(constraint, concrete: Type, store: ^Store = nil) -> b
 	switch constraint {
 	case INT:
 		return is_concrete_integer(concrete)
+	case UINT:
+		return is_unsigned(concrete)
 	case FLOAT:
 		return is_float(concrete)
 	case RANGE:
@@ -1686,6 +1694,19 @@ smallest_signed_for_literal :: proc(value: i64) -> Type {
 	return I64
 }
 
+smallest_unsigned_for_literal :: proc(value: u64) -> Type {
+	if value <= 255 {
+		return U8
+	}
+	if value <= 65535 {
+		return U16
+	}
+	if value <= 4294967295 {
+		return U32
+	}
+	return U64
+}
+
 name :: proc(value: Type) -> string {
 	switch value {
 	case INVALID:       return "<invalid>"
@@ -1693,6 +1714,7 @@ name :: proc(value: Type) -> string {
 	case ANYOPAQUE:     return "anyopaque"
 	case BOOL:          return "bool"
 	case INT:           return "int"
+	case UINT:          return "uint"
 	case FLOAT:         return "float"
 	case RANGE:         return "range"
 	case I8:            return "i8"

compiler_tests.odin

@@ -1485,6 +1485,7 @@ main func() void {
 	_ = maxval!(u8, u16)
 	_ = minval!(1)
 	_ = maxval!(int)
+	_ = maxval!(uint)
 	_ = maxval!(f32)
 	_ = maxval!(bool)
 	_ = maxval!(Named)
@@ -1513,7 +1514,7 @@ main func() void {
 	}
 	testing.expect_value(t, bad_arity, 2)
 	testing.expect(t, bad_type)
-	testing.expect_value(t, bad_target, 5)
+	testing.expect_value(t, bad_target, 6)
 }
 
 @(test)
@@ -12876,3 +12877,189 @@ dependency_passes test {
 	testing.expect(t, strings.contains(output, root_path))
 	testing.expect(t, strings.contains(output, "3 passed, 1 failed"))
 }
+
+@(test)
+uint_constraint_parses_as_type_and_comptime_value :: proc(t: ^testing.T) {
+	text := `value uint :: 1
+Constraint :: uint
+`
+	source_file := source.Source{path="uint.bro", text=text}
+	diagnostics := source.init_diagnostics(&source_file)
+	defer source.destroy_diagnostics(&diagnostics)
+	symbols := symbol.init_table()
+	defer symbol.destroy_table(&symbols)
+	stream := lexer.lex(&source_file, &diagnostics, &symbols)
+	defer delete(stream.items)
+	module := parser.parse(&stream, &source_file, &diagnostics)
+	defer ast.destroy_module(&module)
+
+	testing.expect_value(t, len(diagnostics.items), 0)
+	testing.expect_value(t, len(module.globals), 2)
+	testing.expect_value(t, module.globals[0].type, types.UINT)
+	testing.expect_value(t, module.exprs[module.globals[1].expr].kind, ast.Expr_Kind.Type)
+	testing.expect_value(t, module.exprs[module.globals[1].expr].type, types.UINT)
+}
+
+@(test)
+uint_constraint_uses_smallest_unsigned_types_and_widens :: proc(t: ^testing.T) {
+	text := `Zero uint :: 0
+Byte uint :: 255
+Word uint :: 256
+Dword uint :: 65536
+Maximum uint :: 18446744073709551615
+Counter uint = 1
+
+widen func() uint {
+	value uint = 1
+	value = 1000
+	return value
+}
+
+widen_global func() void { Counter = 1000 }
+
+main func() void {
+	_ = Zero
+	_ = Byte
+	_ = Word
+	_ = Dword
+	_ = Maximum
+	_ = widen()
+	widen_global()
+}
+`
+	source_file := source.Source{path="uint_types.bro", text=text}
+	diagnostics := source.init_diagnostics(&source_file)
+	defer source.destroy_diagnostics(&diagnostics)
+	symbols := symbol.init_table()
+	defer symbol.destroy_table(&symbols)
+	stream := lexer.lex(&source_file, &diagnostics, &symbols)
+	defer delete(stream.items)
+	ast_module := parser.parse(&stream, &source_file, &diagnostics)
+	defer ast.destroy_module(&ast_module)
+	hir_module := checker.check(&ast_module, &diagnostics, &symbols)
+	defer hir.destroy_module(&hir_module)
+
+	expected := []types.Type{types.U8, types.U8, types.U16, types.U32, types.U64, types.U16}
+	for value_type, index in expected {
+		testing.expect_value(t, hir_module.globals[index].type, value_type)
+	}
+	widen_symbol := symbol.intern(&symbols, "widen")
+	found_widen := false
+	for function in hir_module.functions {
+		if function.name != widen_symbol {
+			continue
+		}
+		found_widen = true
+		testing.expect_value(t, function.result, types.U16)
+		testing.expect_value(t, function.locals[0].type, types.U16)
+	}
+	testing.expect_value(t, len(diagnostics.items), 0)
+	testing.expect(t, found_widen)
+}
+
+@(test)
+uint_constraint_infers_boundaries_calls_and_records :: proc(t: ^testing.T) {
+	directory := "/tmp/brolang-test-uint-constraint"
+	main_path := "/tmp/brolang-test-uint-constraint/main.bro"
+	output := "/tmp/brolang-test-uint-constraint-output"
+	text := `Box :: struct { value uint }
+
+identity func(value uint) uint { return value }
+whole func(value int) int { return value }
+max_value func() uint { return 18446744073709551615 }
+
+make_box func(value usize) Box { return Box{value = value} }
+
+main func() i32 {
+	zero uint :: 0
+	byte uint :: 255
+	word uint :: 256
+	word_max uint :: 65535
+	dword uint :: 65536
+	maximum uint :: 18446744073709551615
+	platform usize = 7
+	c_value c_uint = c_uint(9)
+	box Box = make_box(7)
+	signed isize = -1
+	if (identity(zero) != 0) return 1
+	if (identity(byte) != 255) return 2
+	if (identity(word) != 256) return 3
+	if (identity(word_max) != 65535) return 4
+	if (identity(dword) != 65536) return 5
+	if (identity(maximum) != 18446744073709551615) return 6
+	if (box.value != 7) return 7
+	if (signed != -1) return 8
+	if (identity(platform) != 7) return 9
+	if (identity(c_value) != c_value) return 10
+	if (whole(word) != 256) return 11
+	if (max_value() != 18446744073709551615) return 12
+	return 0
+}
+`
+	_ = os2.remove_all(directory)
+	defer _ = os2.remove_all(directory)
+	defer _ = os.remove(output)
+	testing.expect(t, os.make_directory(directory) == nil)
+	testing.expect(t, os.write_entire_file(main_path, transmute([]byte)text))
+	testing.expect_value(t, compiler_core.compile_package(directory, output), 0)
+	state := run_executable(output)
+	testing.expect_value(t, state.exit_code, 0)
+}
+
+@(test)
+uint_constraint_rejects_other_families_and_recovers_records_as_u64 :: proc(t: ^testing.T) {
+	text := `Unresolved :: struct { value uint }
+Conflict :: struct { value uint }
+
+take func(value uint) uint { return value }
+bad_result func() uint { return -1 }
+
+bad func(signed i32, decimal f64) void {
+	_ = take(signed)
+	_ = take(decimal)
+	negative uint :: -1
+	a Conflict = Conflict{value = signed}
+	_ = negative
+	_ = a
+}
+
+Overflow uint :: 18446744073709551616
+NegativeGlobal uint :: -1
+main func() void {
+	bad(1, 1.0)
+	_ = bad_result()
+}
+`
+	source_file := source.Source{path="bad_uint.bro", text=text}
+	diagnostics := source.init_diagnostics(&source_file)
+	defer source.destroy_diagnostics(&diagnostics)
+	symbols := symbol.init_table()
+	defer symbol.destroy_table(&symbols)
+	stream := lexer.lex(&source_file, &diagnostics, &symbols)
+	defer delete(stream.items)
+	ast_module := parser.parse(&stream, &source_file, &diagnostics)
+	defer ast.destroy_module(&ast_module)
+	hir_module := checker.check(&ast_module, &diagnostics, &symbols)
+	defer hir.destroy_module(&hir_module)
+
+	signed_error := false
+	float_error := false
+	negative_error := false
+	field_error := false
+	overflow_error := false
+	global_error := false
+	result_error := false
+	for diagnostic in diagnostics.items {
+		signed_error = signed_error || strings.contains(diagnostic.message, "cannot pass i32 to 'uint' parameter 'value'")
+		float_error = float_error || strings.contains(diagnostic.message, "cannot pass f64 to 'uint' parameter 'value'")
+		negative_error = negative_error || strings.contains(diagnostic.message, "could not resolve the 'uint' constraint for local 'negative'")
+		field_error = field_error || strings.contains(diagnostic.message, "type i32 does not satisfy the 'uint' constraint for field 'Conflict.value'")
+		overflow_error = overflow_error || strings.contains(diagnostic.message, "magnitude does not fit in u64")
+		global_error = global_error || strings.contains(diagnostic.message, "could not resolve the 'uint' constraint for global 'NegativeGlobal'")
+		result_error = result_error || strings.contains(diagnostic.message, "could not resolve a concrete result type for 'bad_result'")
+	}
+	unresolved, unresolved_ok := named_record_field_type(&hir_module, &symbols, "Unresolved", "value")
+	testing.expect(t, signed_error && float_error && negative_error && field_error && overflow_error && global_error && result_error)
+	testing.expect(t, unresolved_ok)
+	testing.expect_value(t, unresolved, types.U64)
+}

extension.toml

@@ -9,5 +9,5 @@ languages = ["languages/brolang"]
 
 [grammars.brolang]
 repository = "file:///Users/valdemar/Developer/Personal/Languages/brolang"
-rev = "2e8234c6a9a12326f230ea16e901ac41a1b48c99"
+rev = "71357b2866d2a558f80b6d5cc65761fb853e74d3"
 path = "tree-sitter-brolang"

tree-sitter-brolang/grammar.js

@@ -228,7 +228,7 @@ module.exports = grammar({
     _type_constant: $ => seq(optional('-'), choice($.integer, $.character)),
 
     builtin_type: _ => choice(
-      'void', 'anyopaque', 'bool', 'int', 'float', 'range',
+      'void', 'anyopaque', 'bool', 'int', 'uint', 'float', 'range',
       'i8', 'i16', 'i32', 'i64', 'u8', 'u16', 'u32', 'u64',
       'isize', 'usize', 'f32', 'f64',
       'c_char', 'c_schar', 'c_uchar', 'c_short', 'c_ushort',

tree-sitter-brolang/src/grammar.json

@@ -1476,6 +1476,10 @@
           "type": "STRING",
           "value": "int"
         },
+        {
+          "type": "STRING",
+          "value": "uint"
+        },
         {
           "type": "STRING",
           "value": "float"

tree-sitter-brolang/src/node-types.json

@@ -2815,6 +2815,10 @@
     "type": "u8",
     "named": false
   },
+  {
+    "type": "uint",
+    "named": false
+  },
   {
     "type": "undefined",
     "named": true

tree-sitter-brolang/test/corpus/syntax.txt

@@ -493,3 +493,19 @@ visit func(kind Kind, value Value) void {
                       (sink))
                     (expression
                       (identifier))))))))))))
+
+==================
+Unsigned constraint
+==================
+
+value uint :: 255
+
+---
+
+(source_file
+  (global_constant_declaration
+    (identifier)
+    (type
+      (builtin_type))
+    (expression
+      (integer))))

tree-sitter-brolang/test/highlight/intrinsics.bro

@@ -1,6 +1,9 @@
 hide helper func() void {}
 # <- keyword
 
+value uint :: 1
+#     ^^^^ type.builtin
+
 main func() void {
 	_ = sizeof!(i32)
 #	    ^^^^^^ function.builtin