Reworks bytes into dynamic array

bytes continues to be the preferred name for u8[...].
Also, putting bytes values into the VM and taking them
out still uses Python bytes values.

This also lets used use the len function on them, for
whatever that's worth.

phasm/compiler.py

@@ -15,8 +15,10 @@ from .type3.types import (
     IntType3,
     Type3,
     TypeApplication_Struct,
+    TypeApplication_Type,
     TypeApplication_TypeInt,
     TypeApplication_TypeStar,
+    TypeConstructor_DynamicArray,
     TypeConstructor_Function,
     TypeConstructor_StaticArray,
     TypeConstructor_Tuple,
@@ -109,12 +111,25 @@ def tuple_instantiation(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.Tu
 
     args: tuple[Type3, ...]
 
-    if isinstance(inp.type3.application, TypeApplication_TypeStar):
+    alloc_size_header = None
+
+    if isinstance(inp.type3.application, TypeApplication_Type):
+        # Possibly paranoid assert. If we have a future variadic type,
+        # does it also do this tuple instantation like this?
+        assert isinstance(inp.type3.application.constructor, TypeConstructor_DynamicArray)
+
+        sa_type, = inp.type3.application.arguments
+
+        args = tuple(sa_type for _ in inp.elements)
+        alloc_size = 4 + calculate_alloc_size(sa_type, is_member=False) * len(inp.elements)
+        alloc_size_header = len(inp.elements)
+    elif isinstance(inp.type3.application, TypeApplication_TypeStar):
         # Possibly paranoid assert. If we have a future variadic type,
         # does it also do this tuple instantation like this?
         assert isinstance(inp.type3.application.constructor, TypeConstructor_Tuple)
 
         args = inp.type3.application.arguments
+        alloc_size = calculate_alloc_size(inp.type3, is_member=False)
     elif isinstance(inp.type3.application, TypeApplication_TypeInt):
         # Possibly paranoid assert. If we have a future type of kind * -> Int -> *,
         # does it also do this tuple instantation like this?
@@ -123,6 +138,7 @@ def tuple_instantiation(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.Tu
         sa_type, sa_len = inp.type3.application.arguments
 
         args = tuple(sa_type for _ in range(sa_len.value))
+        alloc_size = calculate_alloc_size(inp.type3, is_member=False)
     else:
         raise NotImplementedError('tuple_instantiation', inp.type3)
 
@@ -135,12 +151,17 @@ def tuple_instantiation(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.Tu
     wgn.add_statement('nop', comment=f'{tmp_var.name} := ({comment_elements})')
 
     # Allocated the required amounts of bytes in memory
-    wgn.i32.const(calculate_alloc_size(inp.type3, is_member=False))
+    wgn.i32.const(alloc_size)
     wgn.call(stdlib_alloc.__alloc__)
     wgn.local.set(tmp_var)
 
+    if alloc_size_header is not None:
+        wgn.local.get(tmp_var)
+        wgn.i32.const(alloc_size_header)
+        wgn.i32.store()
+
     # Store each element individually
-    offset = 0
+    offset = 0 if alloc_size_header is None else 4
     for element, exp_type3 in zip(inp.elements, args, strict=True):
         assert element.type3 == exp_type3
 

phasm/ourlang.py

@@ -301,6 +301,9 @@ class FunctionParam:
         self.name = name
         self.type3 = type3
 
+    def __repr__(self) -> str:
+        return f'FunctionParam({self.name!r}, {self.type3!r})'
+
 class Function:
     """
     A function processes input and produces output

phasm/parser.py

@@ -655,8 +655,15 @@ class OurVisitor:
 
             if isinstance(node.slice, ast.Slice):
                 _raise_static_error(node, 'Must subscript using an index')
+
             if not isinstance(node.slice, ast.Constant):
                 _raise_static_error(node, 'Must subscript using a constant index')
+
+            if node.slice.value is Ellipsis:
+                return prelude.dynamic_array(
+                    self.visit_type(module, node.value),
+                )
+
             if not isinstance(node.slice.value, int):
                 _raise_static_error(node, 'Must subscript using a constant integer index')
             if not isinstance(node.ctx, ast.Load):

phasm/prelude/__init__.py

@@ -20,6 +20,7 @@ from ..type3.types import (
     Type3,
     TypeApplication_Nullary,
     TypeConstructor_Base,
+    TypeConstructor_DynamicArray,
     TypeConstructor_Function,
     TypeConstructor_StaticArray,
     TypeConstructor_Struct,
@@ -158,9 +159,15 @@ f64 = Type3('f64', TypeApplication_Nullary(None, None))
 A 32-bits IEEE 754 float, of 64 bits width.
 """
 
-bytes_ = Type3('bytes', TypeApplication_Nullary(None, None))
+def da_on_create(args: tuple[Type3], typ: Type3) -> None:
+    instance_type_class(InternalPassAsPointer, typ)
+
+dynamic_array = TypeConstructor_DynamicArray('dynamic_array', on_create=da_on_create)
 """
-This is a runtime-determined length piece of memory that can be indexed at runtime.
+This is a dynamic length piece of memory.
+
+It should be applied with two arguments. It has a runtime
+determined length, and each argument is the same.
 """
 
 def sa_on_create(args: tuple[Type3, IntType3], typ: Type3) -> None:
@@ -168,12 +175,10 @@ def sa_on_create(args: tuple[Type3, IntType3], typ: Type3) -> None:
 
 static_array = TypeConstructor_StaticArray('static_array', on_create=sa_on_create)
 """
-A type constructor.
+This is a fixed length piece of memory.
 
-Any static array is a fixed length piece of memory that can be indexed at runtime.
+It should be applied with two arguments. It has a compile time
-
+determined length, and each argument is the same.
-It should be applied with one argument. It has a runtime-dynamic length
-of the same type repeated.
 """
 
 def tp_on_create(args: tuple[Type3, ...], typ: Type3) -> None:
@@ -208,20 +213,6 @@ This is like a tuple, but each argument is named, so that developers
 can get and set fields by name.
 """
 
-PRELUDE_TYPES: dict[str, Type3] = {
-    'none': none,
-    'bool': bool_,
-    'u8': u8,
-    'u32': u32,
-    'u64': u64,
-    'i8': i8,
-    'i32': i32,
-    'i64': i64,
-    'f32': f32,
-    'f64': f64,
-    'bytes': bytes_,
-}
-
 a = TypeVariable('a', TypeVariableApplication_Nullary(None, None))
 b = TypeVariable('b', TypeVariableApplication_Nullary(None, None))
 
@@ -232,7 +223,7 @@ InternalPassAsPointer = Type3Class('InternalPassAsPointer', (a, ), methods={}, o
 Internal type class to keep track which types we pass arounds as a pointer.
 """
 
-instance_type_class(InternalPassAsPointer, bytes_)
+# instance_type_class(InternalPassAsPointer, bytes_)
 # instance_type_class(InternalPassAsPointer, static_array)
 # instance_type_class(InternalPassAsPointer, tuple_)
 # instance_type_class(InternalPassAsPointer, struct)
@@ -537,12 +528,15 @@ instance_type_class(Floating, f64, methods={
     'sqrt': stdtypes.f64_floating_sqrt,
 })
 
-Sized_ = Type3Class('Sized', (a, ), methods={
+Sized_ = Type3Class('Sized', (t, ), methods={
-    'len': [a, u32],
+    'len': [t(a), u32],
 }, operators={})  # FIXME: Once we get type class families, add [] here
 
-instance_type_class(Sized_, bytes_, methods={
+instance_type_class(Sized_, dynamic_array, methods={
-    'len': stdtypes.bytes_sized_len,
+    'len': stdtypes.dynamic_array_sized_len,
+})
+instance_type_class(Sized_, static_array, methods={
+    'len': stdtypes.static_array_sized_len,
 })
 
 Extendable = Type3Class('Extendable', (a, b, ), methods={
@@ -595,6 +589,22 @@ instance_type_class(Foldable, static_array, methods={
     'sum': stdtypes.static_array_sum,
 })
 
+bytes_ = dynamic_array(u8)
+
+PRELUDE_TYPES: dict[str, Type3] = {
+    'none': none,
+    'bool': bool_,
+    'u8': u8,
+    'u32': u32,
+    'u64': u64,
+    'i8': i8,
+    'i32': i32,
+    'i64': i64,
+    'f32': f32,
+    'f64': f64,
+    'bytes': bytes_,
+}
+
 PRELUDE_TYPE_CLASSES = {
     'Eq': Eq,
     'Ord': Ord,

phasm/stdlib/types.py

@@ -1006,11 +1006,19 @@ def f64_intnum_neg(g: Generator, tv_map: TypeVariableLookup) -> None:
 ## ###
 ## Class Sized
 
-def bytes_sized_len(g: Generator, tv_map: TypeVariableLookup) -> None:
+def dynamic_array_sized_len(g: Generator, tv_map: TypeVariableLookup) -> None:
     del tv_map
     # The length is stored in the first 4 bytes
     g.i32.load()
 
+def static_array_sized_len(g: Generator, tv_map: TypeVariableLookup) -> None:
+    assert len(tv_map) == 1
+    sa_type, sa_len = next(iter(tv_map.values()))
+    assert isinstance(sa_type, Type3)
+    assert isinstance(sa_len, IntType3)
+
+    g.i32.const(sa_len.value)
+
 ## ###
 ## Extendable
 

phasm/type3/constraints.py

@@ -15,6 +15,7 @@ from .types import (
     Type3,
     TypeApplication_Nullary,
     TypeApplication_Struct,
+    TypeApplication_Type,
     TypeApplication_TypeInt,
     TypeApplication_TypeStar,
     TypeConstructor_Base,
@@ -292,6 +293,14 @@ class TupleMatchConstraint(ConstraintBase):
         self.exp_type = exp_type
         self.args = list(args)
 
+    def _generate_dynamic_array(self, sa_args: tuple[Type3]) -> CheckResult:
+        sa_type, = sa_args
+
+        return [
+            SameTypeConstraint(arg, sa_type)
+            for arg in self.args
+        ]
+
     def _generate_static_array(self, sa_args: tuple[Type3, IntType3]) -> CheckResult:
         sa_type, sa_len = sa_args
 
@@ -313,6 +322,7 @@ class TupleMatchConstraint(ConstraintBase):
         ]
 
     GENERATE_ROUTER = TypeApplicationRouter['TupleMatchConstraint', CheckResult]()
+    GENERATE_ROUTER.add(prelude.dynamic_array, _generate_dynamic_array)
     GENERATE_ROUTER.add(prelude.static_array, _generate_static_array)
     GENERATE_ROUTER.add(prelude.tuple_, _generate_tuple)
 
@@ -340,7 +350,7 @@ class MustImplementTypeClassConstraint(ConstraintBase):
     types: list[Type3OrPlaceholder]
 
     DATA = {
-        'bytes': {'Foldable'},
+        'dynamic_array': {'Foldable'},
     }
 
     def __init__(self, context: Context, type_class3: Union[str, Type3Class], typ_list: list[Type3OrPlaceholder], comment: Optional[str] = None) -> None:
@@ -363,7 +373,7 @@ class MustImplementTypeClassConstraint(ConstraintBase):
                 typ_list.append(typ)
                 continue
 
-            if isinstance(typ.application, (TypeApplication_TypeInt, TypeApplication_TypeStar)):
+            if isinstance(typ.application, (TypeApplication_Type, TypeApplication_TypeInt, TypeApplication_TypeStar)):
                 typ_list.append(typ.application.constructor)
                 continue
 
@@ -420,6 +430,29 @@ class LiteralFitsConstraint(ConstraintBase):
         self.type3 = type3
         self.literal = literal
 
+    def _generate_dynamic_array(self, da_args: tuple[Type3]) -> CheckResult:
+        if not isinstance(self.literal, ourlang.ConstantTuple):
+            return Error('Must be tuple', comment=self.comment)
+
+        da_type, = da_args
+
+        res: list[ConstraintBase] = []
+
+        res.extend(
+            LiteralFitsConstraint(da_type, y)
+            for y in self.literal.value
+        )
+
+        # Generate placeholders so each Literal expression
+        # gets updated when we figure out the type of the
+        # expression the literal is used in
+        res.extend(
+            SameTypeConstraint(da_type, PlaceholderForType([y]))
+            for y in self.literal.value
+        )
+
+        return res
+
     def _generate_static_array(self, sa_args: tuple[Type3, IntType3]) -> CheckResult:
         if not isinstance(self.literal, ourlang.ConstantTuple):
             return Error('Must be tuple', comment=self.comment)
@@ -501,6 +534,7 @@ class LiteralFitsConstraint(ConstraintBase):
         return res
 
     GENERATE_ROUTER = TypeApplicationRouter['LiteralFitsConstraint', CheckResult]()
+    GENERATE_ROUTER.add(prelude.dynamic_array, _generate_dynamic_array)
     GENERATE_ROUTER.add(prelude.static_array, _generate_static_array)
     GENERATE_ROUTER.add(prelude.struct, _generate_struct)
     GENERATE_ROUTER.add(prelude.tuple_, _generate_tuple)

phasm/type3/constraintsgenerator.py

@@ -176,7 +176,10 @@ def _expression_function_call(
         if not isinstance(sig_arg.application, TypeVariableApplication_Unary):
             raise NotImplementedError(sig_arg.application)
 
-        assert sig_arg.application.arguments in type_var_map  # When does this happen?
+        if sig_arg.application.arguments not in type_var_map:
+            # e.g., len :: t a -> u32
+            # i.e. "a" does not matter at all
+            continue
 
         yield SameTypeArgumentConstraint(
             type_var_map[sig_arg],

phasm/type3/routers.py

@@ -6,7 +6,13 @@ from .functions import (
     TypeVariableApplication_Unary,
 )
 from .typeclasses import Type3ClassArgs
-from .types import KindArgument, Type3, TypeApplication_TypeInt, TypeConstructor_Base
+from .types import (
+    KindArgument,
+    Type3,
+    TypeApplication_Type,
+    TypeApplication_TypeInt,
+    TypeConstructor_Base,
+)
 
 
 class NoRouteForTypeException(Exception):
@@ -104,6 +110,10 @@ class TypeClassArgsRouter[S, R]:
                 key.append(typ.application.constructor)
 
                 if isinstance(tvar.application, TypeVariableApplication_Unary):
+                    if isinstance(typ.application, TypeApplication_Type):
+                        arguments[tvar.application.arguments] = typ.application.arguments
+                        continue
+
                     # FIXME: This feels sketchy. Shouldn't the type variable
                     # have the exact same number as arguments?
                     if isinstance(typ.application, TypeApplication_TypeInt):

phasm/type3/types.py

@@ -195,6 +195,26 @@ class TypeConstructor_Base[T]:
     def __repr__(self) -> str:
         return f'{self.__class__.__name__}({self.name!r}, ...)'
 
+class TypeConstructor_Type(TypeConstructor_Base[Tuple[Type3]]):
+    """
+    Base class type constructors of kind: * -> *
+
+    Notably, static array.
+    """
+    __slots__ = ()
+
+    def make_application(self, key: Tuple[Type3]) -> 'TypeApplication_Type':
+        return TypeApplication_Type(self, key)
+
+    def make_name(self, key: Tuple[Type3]) -> str:
+        return f'{self.name} {key[0].name} '
+
+    def __call__(self, arg0: Type3) -> Type3:
+        return self.construct((arg0, ))
+
+class TypeApplication_Type(TypeApplication_Base[TypeConstructor_Type, Tuple[Type3]]):
+    pass
+
 class TypeConstructor_TypeInt(TypeConstructor_Base[Tuple[Type3, IntType3]]):
     """
     Base class type constructors of kind: * -> Int -> *
@@ -231,6 +251,13 @@ class TypeConstructor_TypeStar(TypeConstructor_Base[Tuple[Type3, ...]]):
 class TypeApplication_TypeStar(TypeApplication_Base[TypeConstructor_TypeStar, Tuple[Type3, ...]]):
     pass
 
+class TypeConstructor_DynamicArray(TypeConstructor_Type):
+    def make_name(self, key: Tuple[Type3]) -> str:
+        if 'u8' == key[0].name:
+            return 'bytes'
+
+        return f'{key[0].name}[...]'
+
 class TypeConstructor_StaticArray(TypeConstructor_TypeInt):
     def make_name(self, key: Tuple[Type3, IntType3]) -> str:
         return f'{key[0].name}[{key[1].value}]'

tests/integration/helpers.py

@@ -152,6 +152,25 @@ def _allocate_memory_stored_bytes(attrs: tuple[runners.RunnerBase, bytes]) -> in
     runner.interpreter_write_memory(adr + 4, val)
     return adr
 
+def _allocate_memory_stored_dynamic_array(attrs: tuple[runners.RunnerBase, Any], da_args: tuple[type3types.Type3]) -> int:
+    runner, val = attrs
+
+    da_type, = da_args
+
+    if not isinstance(val, tuple):
+        raise InvalidArgumentException(f'Expected tuple; got {val!r} instead')
+
+    alloc_size = 4 + len(val) * calculate_alloc_size(da_type, True)
+    adr = runner.call('stdlib.alloc.__alloc__', alloc_size)
+    assert isinstance(adr, int)  # Type int
+    sys.stderr.write(f'Allocation 0x{adr:08x} {repr(val)}\n')
+
+    offset = adr
+    offset += _write_memory_stored_value(runner, offset, prelude.u32, len(val))
+    for val_el_val in val:
+        offset += _write_memory_stored_value(runner, offset, da_type, val_el_val)
+    return adr
+
 def _allocate_memory_stored_static_array(attrs: tuple[runners.RunnerBase, Any], sa_args: tuple[type3types.Type3, type3types.IntType3]) -> int:
     runner, val = attrs
 
@@ -211,6 +230,7 @@ def _allocate_memory_stored_tuple(attrs: tuple[runners.RunnerBase, Any], tp_args
 
 ALLOCATE_MEMORY_STORED_ROUTER = TypeApplicationRouter[tuple[runners.RunnerBase, Any], Any]()
 ALLOCATE_MEMORY_STORED_ROUTER.add_n(prelude.bytes_, _allocate_memory_stored_bytes)
+ALLOCATE_MEMORY_STORED_ROUTER.add(prelude.dynamic_array, _allocate_memory_stored_dynamic_array)
 ALLOCATE_MEMORY_STORED_ROUTER.add(prelude.static_array, _allocate_memory_stored_static_array)
 ALLOCATE_MEMORY_STORED_ROUTER.add(prelude.struct, _allocate_memory_stored_struct)
 ALLOCATE_MEMORY_STORED_ROUTER.add(prelude.tuple_, _allocate_memory_stored_tuple)
@@ -325,6 +345,26 @@ def _split_read_bytes(all_bytes: bytes, split_sizes: Iterable[int]) -> Generator
         yield all_bytes[offset:offset + size]
         offset += size
 
+def _load_dynamic_array_from_address(attrs: tuple[runners.RunnerBase, int], da_args: tuple[type3types.Type3]) -> Any:
+    runner, adr = attrs
+    da_type, = da_args
+
+    sys.stderr.write(f'Reading 0x{adr:08x} {da_type:s}[...]\n')
+
+    read_bytes = runner.interpreter_read_memory(adr, 4)
+    array_len,  = struct.unpack('<I', read_bytes)
+    adr += 4
+
+    arg_size_1 = calculate_alloc_size(da_type, is_member=True)
+    arg_sizes = [arg_size_1 for _ in range(array_len)] # _split_read_bytes requires one arg per value
+
+    read_bytes = runner.interpreter_read_memory(adr, sum(arg_sizes))
+
+    return tuple(
+        _unpack(runner, da_type, arg_bytes)
+        for arg_bytes in _split_read_bytes(read_bytes, arg_sizes)
+    )
+
 def _load_static_array_from_address(attrs: tuple[runners.RunnerBase, int], sa_args: tuple[type3types.Type3, type3types.IntType3]) -> Any:
     runner, adr = attrs
     sub_typ, len_typ = sa_args
@@ -379,6 +419,7 @@ def _load_tuple_from_address(attrs: tuple[runners.RunnerBase, int], tp_args: tup
 
 LOAD_FROM_ADDRESS_ROUTER = TypeApplicationRouter[tuple[runners.RunnerBase, int], Any]()
 LOAD_FROM_ADDRESS_ROUTER.add_n(prelude.bytes_, _load_bytes_from_address)
+LOAD_FROM_ADDRESS_ROUTER.add(prelude.dynamic_array, _load_dynamic_array_from_address)
 LOAD_FROM_ADDRESS_ROUTER.add(prelude.static_array, _load_static_array_from_address)
 LOAD_FROM_ADDRESS_ROUTER.add(prelude.struct, _load_struct_from_address)
 LOAD_FROM_ADDRESS_ROUTER.add(prelude.tuple_, _load_tuple_from_address)

tests/integration/test_lang/generator.md

@@ -60,7 +60,7 @@ CONSTANT: (u32, ) = $VAL0
 ```
 
 ```py
-if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_'):
+if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('dynamic_array_'):
     expect_type_error(
         'Tuple element count mismatch',
         'The given literal must fit the expected type',
@@ -113,7 +113,7 @@ def testEntry() -> i32:
 ```
 
 ```py
-if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_'):
+if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('dynamic_array_'):
     expect_type_error(
         'Mismatch between applied types argument count',
         'The type of a tuple is a combination of its members',
@@ -175,7 +175,7 @@ def testEntry() -> i32:
 ```
 
 ```py
-if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('struct_'):
+if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('dynamic_array_') or TYPE_NAME.startswith('struct_'):
     expect_type_error(
         TYPE + ' must be (u32, ) instead',
         'The type of the value returned from function constant should match its return type',
@@ -226,7 +226,7 @@ def select(x: $TYPE) -> (u32, ):
 ```
 
 ```py
-if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('struct_'):
+if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('dynamic_array_') or TYPE_NAME.startswith('struct_'):
     expect_type_error(
         TYPE + ' must be (u32, ) instead',
         'The type of the value returned from function select should match its return type',
@@ -273,7 +273,7 @@ def testEntry() -> i32:
 ```
 
 ```py
-if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_'):
+if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('dynamic_array_'):
     expect_type_error(
         'Mismatch between applied types argument count',
         # FIXME: Shouldn't this be the same as for the else statement?
@@ -330,7 +330,7 @@ def testEntry() -> i32:
 ```
 
 ```py
-if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('struct_'):
+if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('dynamic_array_') or TYPE_NAME.startswith('struct_'):
     expect_type_error(
         TYPE + ' must be (u32, ) instead',
         'The type of the value passed to argument 0 of function helper should match the type of that argument',

tests/integration/test_lang/generator_dynamic_array_u64.json

@@ -0,0 +1,5 @@
+{
+	"TYPE_NAME": "dynamic_array_u64",
+	"TYPE": "u64[...]",
+	"VAL0": "(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, )"
+}

tests/integration/test_typeclasses/test_sized.py

@@ -6,7 +6,7 @@ from ..helpers import Suite
 @pytest.mark.integration_test
 @pytest.mark.parametrize('type_, in_put, exp_result', [
     ('bytes', b'Hello, world!', 13),
-    # ('u8[4]', (1, 2, 3, 4), 4),  # FIXME: Implement this
+    ('u8[4]', (1, 2, 3, 4), 4),
 ])
 def test_len(type_, in_put, exp_result):
     code_py = f"""