Removes the special casing for foldl

Had to implement both functions as arguments and type
place holders (variables) for type constructors.

Had to implement functions as a type as well.

Still have to figure out how to pass functions around.

TODO.md

@@ -7,7 +7,6 @@
 
 - Implement a trace() builtin for debugging
 - Check if we can use DataView in the Javascript examples, e.g. with setUint32
-- Storing u8 in memory still claims 32 bits (since that's what you need in local variables). However, using load8_u / loadu_s we can optimize this.
 - Implement a FizzBuzz example
 - Also, check the codes for FIXME and TODO
 - Allocation is done using pointers for members, is this desired?
@@ -17,9 +16,11 @@
   - Clean up Subscript implementation - it's half implemented in the compiler. Makes more sense to move more parts to stdlib_types.
 - Have a set of rules or guidelines for the constraint comments, they're messy.
 - Why is expression_subscript_bytes using a helper method but expression_subscript_static_array is not?
+- calculate_alloc_size can be reworked; is_member isn't useful with TYPE_INFO_MAP
 
 - Parser is putting stuff in ModuleDataBlock
   - Surely the compiler should build data blocks
+  - Also put the struct.pack constants in TYPE_INFO_MAP
 - Make prelude more an actual thing
   - Merge in compiler.INSTANCES
   - Make it less build in - have a environment class of some kind
@@ -30,3 +31,5 @@
   - Functions don't seem to be a thing on typing level yet?
   - Related to the FIXME in phasm_type3?
   - Type constuctor should also be able to constuct placeholders - somehow.
+
+- Read https://bytecodealliance.org/articles/multi-value-all-the-wasm

phasm/codestyle.py

@@ -105,10 +105,6 @@ def expression(inp: ourlang.Expression) -> str:
     if isinstance(inp, ourlang.AccessStructMember):
         return f'{expression(inp.varref)}.{inp.member}'
 
-    if isinstance(inp, ourlang.Fold):
-        fold_name = 'foldl' if ourlang.Fold.Direction.LEFT == inp.dir else 'foldr'
-        return f'{fold_name}({inp.func.name}, {expression(inp.base)}, {expression(inp.iter)})'
-
     raise NotImplementedError(expression, inp)
 
 def statement(inp: ourlang.Statement) -> Statements:

phasm/compiler.py

@@ -2,13 +2,14 @@
 This module contains the code to convert parsed Ourlang into WebAssembly code
 """
 import struct
-from typing import List, Optional
+from typing import List
 
-from . import codestyle, ourlang, prelude, wasm
+from . import ourlang, prelude, wasm
 from .runtime import calculate_alloc_size, calculate_member_offset
 from .stdlib import alloc as stdlib_alloc
 from .stdlib import types as stdlib_types
-from .type3.functions import TypeVariable
+from .stdlib.types import TYPE_INFO_CONSTRUCTED, TYPE_INFO_MAP
+from .type3.functions import FunctionArgument, TypeVariable
 from .type3.routers import NoRouteForTypeException, TypeApplicationRouter
 from .type3.typeclasses import Type3ClassMethod
 from .type3.types import (
@@ -27,20 +28,6 @@ from .wasmgenerator import Generator as WasmGenerator
 
 TYPE3_ASSERTION_ERROR = 'You must call phasm_type3 after calling phasm_parse before your program can be compiled'
 
-LOAD_STORE_TYPE_MAP = {
-    'i8': 'i32', # Have to use an u32, since there is no native i8 type
-    'u8': 'i32', # Have to use an u32, since there is no native u8 type
-
-    'i32': 'i32',
-    'i64': 'i64',
-    'u32': 'i32',
-    'u64': 'i64',
-    'f32': 'f32',
-    'f64': 'f64',
-
-    'bytes': 'i32', # Bytes are passed around as pointers
-}
-
 def phasm_compile(inp: ourlang.Module) -> wasm.Module:
     """
     Public method for compiling a parsed Phasm module into
@@ -55,53 +42,8 @@ def type3(inp: Type3) -> wasm.WasmType:
     Types are used for example in WebAssembly function parameters
     and return types.
     """
-    assert inp is not None, TYPE3_ASSERTION_ERROR
-
-    if inp == prelude.none:
-        return wasm.WasmTypeNone()
-
-    if inp == prelude.bool_:
-        # WebAssembly stores booleans as i32
-        # See e.g. f32.eq, which is [f32 f32] -> [i32]
-        return wasm.WasmTypeInt32()
-
-    if inp == prelude.u8:
-        # WebAssembly has only support for 32 and 64 bits
-        # So we need to store more memory per byte
-        return wasm.WasmTypeInt32()
-
-    if inp == prelude.u32:
-        return wasm.WasmTypeInt32()
-
-    if inp == prelude.u64:
-        return wasm.WasmTypeInt64()
-
-    if inp == prelude.i8:
-        # WebAssembly has only support for 32 and 64 bits
-        # So we need to store more memory per byte
-        return wasm.WasmTypeInt32()
-
-    if inp == prelude.i32:
-        return wasm.WasmTypeInt32()
-
-    if inp == prelude.i64:
-        return wasm.WasmTypeInt64()
-
-    if inp == prelude.f32:
-        return wasm.WasmTypeFloat32()
-
-    if inp == prelude.f64:
-        return wasm.WasmTypeFloat64()
-
-    if inp == prelude.bytes_:
-        # bytes are passed as pointer
-        # And pointers are i32
-        return wasm.WasmTypeInt32()
-
-    if (prelude.InternalPassAsPointer, (inp, )) in prelude.PRELUDE_TYPE_CLASS_INSTANCES_EXISTING:
-        return wasm.WasmTypeInt32()
-
-    raise NotImplementedError(type3, inp)
+    typ_info = TYPE_INFO_MAP.get(inp.name, TYPE_INFO_CONSTRUCTED)
+    return typ_info.wasm_type()
 
 def tuple_instantiation(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.TupleInstantiation) -> None:
     """
@@ -121,7 +63,9 @@ def tuple_instantiation(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.Tu
         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)
+        # Can't use calculate_alloc_size directly since that doesn't
+        # know the dynamic array's length
+        alloc_size = 4 + calculate_alloc_size(sa_type, is_member=True) * 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,
@@ -165,15 +109,12 @@ def tuple_instantiation(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.Tu
     for element, exp_type3 in zip(inp.elements, args, strict=True):
         assert element.type3 == exp_type3
 
-        if (prelude.InternalPassAsPointer, (exp_type3, )) in prelude.PRELUDE_TYPE_CLASS_INSTANCES_EXISTING:
-            mtyp = 'i32'
-        else:
-            mtyp = LOAD_STORE_TYPE_MAP[exp_type3.name]
+        exp_type_info = TYPE_INFO_MAP.get(exp_type3.name, TYPE_INFO_CONSTRUCTED)
 
         wgn.add_statement('nop', comment='PRE')
         wgn.local.get(tmp_var)
         expression(wgn, mod, element)
-        wgn.add_statement(f'{mtyp}.store', 'offset=' + str(offset))
+        wgn.add_statement(exp_type_info.wasm_store_func, 'offset=' + str(offset))
         wgn.add_statement('nop', comment='POST')
 
         offset += calculate_alloc_size(exp_type3, is_member=True)
@@ -213,14 +154,14 @@ def expression_subscript_static_array(
     with wgn.if_():
         wgn.unreachable(comment='Out of bounds')
 
+    el_type_info = TYPE_INFO_MAP.get(el_type.name, TYPE_INFO_CONSTRUCTED)
+
     wgn.local.get(tmp_var)
-    wgn.i32.const(calculate_alloc_size(el_type))
+    wgn.i32.const(el_type_info.alloc_size)
     wgn.i32.mul()
     wgn.i32.add()
 
-    mtyp = LOAD_STORE_TYPE_MAP[el_type.name]
-
-    wgn.add_statement(f'{mtyp}.load')
+    wgn.add_statement(el_type_info.wasm_load_func)
 
 def expression_subscript_tuple(
         attrs: tuple[WasmGenerator, ourlang.Module, ourlang.Subscript],
@@ -234,19 +175,16 @@ def expression_subscript_tuple(
     offset = 0
     for el_type in args[0:inp.index.value]:
         assert el_type is not None, TYPE3_ASSERTION_ERROR
-        offset += calculate_alloc_size(el_type)
+        el_type_info = TYPE_INFO_MAP.get(el_type.name, TYPE_INFO_CONSTRUCTED)
+        offset += el_type_info.alloc_size
 
     el_type = args[inp.index.value]
     assert el_type is not None, TYPE3_ASSERTION_ERROR
 
     expression(wgn, mod, inp.varref)
 
-    if (prelude.InternalPassAsPointer, (el_type, )) in prelude.PRELUDE_TYPE_CLASS_INSTANCES_EXISTING:
-        mtyp = 'i32'
-    else:
-        mtyp = LOAD_STORE_TYPE_MAP[el_type.name]
-
-    wgn.add_statement(f'{mtyp}.load', f'offset={offset}')
+    el_type_info = TYPE_INFO_MAP.get(el_type.name, TYPE_INFO_CONSTRUCTED)
+    wgn.add_statement(el_type_info.wasm_load_func, f'offset={offset}')
 
 SUBSCRIPT_ROUTER = TypeApplicationRouter[tuple[WasmGenerator, ourlang.Module, ourlang.Subscript], None]()
 SUBSCRIPT_ROUTER.add_n(prelude.bytes_, expression_subscript_bytes)
@@ -305,7 +243,7 @@ def expression(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.Expression)
         if isinstance(inp.variable, ourlang.ModuleConstantDef):
             assert inp.type3 is not None, TYPE3_ASSERTION_ERROR
 
-            if (prelude.InternalPassAsPointer, (inp.type3, )) in prelude.PRELUDE_TYPE_CLASS_INSTANCES_EXISTING:
+            if inp.type3.name not in TYPE_INFO_MAP:
                 assert isinstance(inp.variable.constant, (ourlang.ConstantBytes, ourlang.ConstantStruct, ourlang.ConstantTuple, ))
 
                 address = inp.variable.constant.data_block.address
@@ -335,6 +273,10 @@ def expression(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.Expression)
                 type_var_map[type_var] = arg_expr.type3
                 continue
 
+            if isinstance(type_var, FunctionArgument):
+                # Fixed type, not part of the lookup requirements
+                continue
+
             raise NotImplementedError(type_var, arg_expr.type3)
 
         router = prelude.PRELUDE_TYPE_CLASS_INSTANCE_METHODS[inp.operator]
@@ -360,6 +302,10 @@ def expression(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.Expression)
                     type_var_map[type_var] = arg_expr.type3
                     continue
 
+                if isinstance(type_var, FunctionArgument):
+                    # Fixed type, not part of the lookup requirements
+                    continue
+
                 raise NotImplementedError(type_var, arg_expr.type3)
 
             router = prelude.PRELUDE_TYPE_CLASS_INSTANCE_METHODS[inp.function]
@@ -413,99 +359,16 @@ def expression(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.Expression)
         assert isinstance(inp.struct_type3.application, TypeApplication_Struct)
 
         member_type = dict(inp.struct_type3.application.arguments)[inp.member]
-
-        mtyp = LOAD_STORE_TYPE_MAP[member_type.name]
+        member_type_info = TYPE_INFO_MAP.get(member_type.name, TYPE_INFO_CONSTRUCTED)
 
         expression(wgn, mod, inp.varref)
-        wgn.add_statement(f'{mtyp}.load', 'offset=' + str(calculate_member_offset(
+        wgn.add_statement(member_type_info.wasm_load_func, 'offset=' + str(calculate_member_offset(
             inp.struct_type3.name, inp.struct_type3.application.arguments, inp.member
         )))
         return
 
-    if isinstance(inp, ourlang.Fold):
-        expression_fold(wgn, mod, inp)
-        return
-
     raise NotImplementedError(expression, inp)
 
-def expression_fold(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.Fold) -> None:
-    """
-    Compile: Fold expression
-    """
-    assert inp.type3 is not None, TYPE3_ASSERTION_ERROR
-
-    if inp.iter.type3 is not prelude.bytes_:
-        raise NotImplementedError(expression_fold, inp, inp.iter.type3)
-
-    wgn.add_statement('nop', comment='acu :: u8')
-    acu_var = wgn.temp_var_u8(f'fold_{codestyle.type3(inp.type3)}_acu')
-    wgn.add_statement('nop', comment='adr :: bytes*')
-    adr_var = wgn.temp_var_i32('fold_i32_adr')
-    wgn.add_statement('nop', comment='len :: i32')
-    len_var = wgn.temp_var_i32('fold_i32_len')
-
-    wgn.add_statement('nop', comment='acu = base')
-    expression(wgn, mod, inp.base)
-    wgn.local.set(acu_var)
-
-    wgn.add_statement('nop', comment='adr = adr(iter)')
-    expression(wgn, mod, inp.iter)
-    wgn.local.set(adr_var)
-
-    wgn.add_statement('nop', comment='len = len(iter)')
-    wgn.local.get(adr_var)
-    wgn.i32.load()
-    wgn.local.set(len_var)
-
-    wgn.add_statement('nop', comment='i = 0')
-    idx_var = wgn.temp_var_i32(f'fold_{codestyle.type3(inp.type3)}_idx')
-    wgn.i32.const(0)
-    wgn.local.set(idx_var)
-
-    wgn.add_statement('nop', comment='if i < len')
-    wgn.local.get(idx_var)
-    wgn.local.get(len_var)
-    wgn.i32.lt_u()
-    with wgn.if_():
-        # From here on, adr_var is the address of byte we're referencing
-        # This is akin to calling stdlib_types.__subscript_bytes__
-        # But since we already know we are inside of bounds,
-        # can just bypass it and load the memory directly.
-        wgn.local.get(adr_var)
-        wgn.i32.const(3) # Bytes header -1, since we do a +1 every loop
-        wgn.i32.add()
-        wgn.local.set(adr_var)
-
-        wgn.add_statement('nop', comment='while True')
-        with wgn.loop():
-            wgn.add_statement('nop', comment='acu = func(acu, iter[i])')
-            wgn.local.get(acu_var)
-
-            # Get the next byte, write back the address
-            wgn.local.get(adr_var)
-            wgn.i32.const(1)
-            wgn.i32.add()
-            wgn.local.tee(adr_var)
-            wgn.i32.load8_u()
-
-            wgn.add_statement('call', f'${inp.func.name}')
-            wgn.local.set(acu_var)
-
-            wgn.add_statement('nop', comment='i = i + 1')
-            wgn.local.get(idx_var)
-            wgn.i32.const(1)
-            wgn.i32.add()
-            wgn.local.set(idx_var)
-
-            wgn.add_statement('nop', comment='if i >= len: break')
-            wgn.local.get(idx_var)
-            wgn.local.get(len_var)
-            wgn.i32.lt_u()
-            wgn.br_if(0)
-
-    # return acu
-    wgn.local.get(acu_var)
-
 def statement_return(wgn: WasmGenerator, mod: ourlang.Module, inp: ourlang.StatementReturn) -> None:
     """
     Compile: Return statement
@@ -600,10 +463,8 @@ def function(mod: ourlang.Module, inp: ourlang.Function) -> wasm.Function:
 def module_data_u8(inp: int) -> bytes:
     """
     Compile: module data, u8 value
-
-    # FIXME: All u8 values are stored as u32
     """
-    return struct.pack('<I', inp) # Should be 'B'
+    return struct.pack('<B', inp)
 
 def module_data_u32(inp: int) -> bytes:
     """
@@ -620,10 +481,8 @@ def module_data_u64(inp: int) -> bytes:
 def module_data_i8(inp: int) -> bytes:
     """
     Compile: module data, i8 value
-
-    # FIXME: All i8 values are stored as i32
     """
-    return struct.pack('<i', inp) # Should be a 'b'
+    return struct.pack('<b', inp)
 
 def module_data_i32(inp: int) -> bytes:
     """
@@ -812,18 +671,11 @@ def _generate_struct_constructor(wgn: WasmGenerator, inp: ourlang.StructConstruc
 
     # Store each member individually
     for memname, mtyp3 in st_args:
-        mtyp: Optional[str]
-        if (prelude.InternalPassAsPointer, (mtyp3, )) in prelude.PRELUDE_TYPE_CLASS_INSTANCES_EXISTING:
-            mtyp = 'i32'
-        else:
-            mtyp = LOAD_STORE_TYPE_MAP.get(mtyp3.name)
-
-        if mtyp is None:
-            raise NotImplementedError(expression, inp, mtyp3)
+        mtyp3_info = TYPE_INFO_MAP.get(mtyp3.name, TYPE_INFO_CONSTRUCTED)
 
         wgn.local.get(tmp_var)
         wgn.add_statement('local.get', f'${memname}')
-        wgn.add_statement(f'{mtyp}.store', 'offset=' + str(calculate_member_offset(
+        wgn.add_statement(mtyp3_info.wasm_store_func, 'offset=' + str(calculate_member_offset(
             inp.struct_type3.name, st_args, memname
         )))
 

phasm/ourlang.py

@@ -1,7 +1,6 @@
 """
 Contains the syntax tree for ourlang
 """
-import enum
 from typing import Dict, Iterable, List, Optional, Union
 
 from . import prelude
@@ -219,36 +218,6 @@ class AccessStructMember(Expression):
         self.struct_type3 = struct_type3
         self.member = member
 
-class Fold(Expression):
-    """
-    A (left or right) fold
-    """
-    class Direction(enum.Enum):
-        """
-        Which direction to fold in
-        """
-        LEFT = 0
-        RIGHT = 1
-
-    dir: Direction
-    func: 'Function'
-    base: Expression
-    iter: Expression
-
-    def __init__(
-            self,
-            dir_: Direction,
-            func: 'Function',
-            base: Expression,
-            iter_: Expression,
-        ) -> None:
-        super().__init__()
-
-        self.dir = dir_
-        self.func = func
-        self.base = base
-        self.iter = iter_
-
 class Statement:
     """
     A statement within a function

phasm/parser.py

@@ -14,7 +14,6 @@ from .ourlang import (
     ConstantStruct,
     ConstantTuple,
     Expression,
-    Fold,
     Function,
     FunctionCall,
     FunctionParam,
@@ -467,7 +466,7 @@ class OurVisitor:
 
         raise NotImplementedError(f'{node} as expr in FunctionDef')
 
-    def visit_Module_FunctionDef_Call(self, module: Module, function: Function, our_locals: OurLocals, node: ast.Call) -> Union[Fold, FunctionCall]:
+    def visit_Module_FunctionDef_Call(self, module: Module, function: Function, our_locals: OurLocals, node: ast.Call) -> Union[FunctionCall]:
         if node.keywords:
             _raise_static_error(node, 'Keyword calling not supported') # Yet?
 
@@ -480,28 +479,6 @@ class OurVisitor:
 
         if node.func.id in PRELUDE_METHODS:
             func = PRELUDE_METHODS[node.func.id]
-        elif node.func.id == 'foldl':
-            if 3 != len(node.args):
-                _raise_static_error(node, f'Function {node.func.id} requires 3 arguments but {len(node.args)} are given')
-
-            # TODO: This is not generic, you cannot return a function
-            subnode = node.args[0]
-            if not isinstance(subnode, ast.Name):
-                raise NotImplementedError(f'Calling methods that are not a name {subnode}')
-            if not isinstance(subnode.ctx, ast.Load):
-                _raise_static_error(subnode, 'Must be load context')
-            if subnode.id not in module.functions:
-                _raise_static_error(subnode, 'Reference to undefined function')
-            func = module.functions[subnode.id]
-            if 2 != len(func.posonlyargs):
-                _raise_static_error(node, f'Function {node.func.id} requires a function with 2 arguments but a function with {len(func.posonlyargs)} args is given')
-
-            return Fold(
-                Fold.Direction.LEFT,
-                func,
-                self.visit_Module_FunctionDef_expr(module, function, our_locals, node.args[1]),
-                self.visit_Module_FunctionDef_expr(module, function, our_locals, node.args[2]),
-            )
         elif node.func.id in our_locals:
             func = our_locals[node.func.id]
         else:

phasm/prelude/__init__.py

@@ -16,7 +16,6 @@ from ..type3.functions import (
 from ..type3.routers import TypeClassArgsRouter, TypeVariableLookup
 from ..type3.typeclasses import Type3Class, Type3ClassMethod
 from ..type3.types import (
-    IntType3,
     Type3,
     TypeApplication_Nullary,
     TypeConstructor_Base,
@@ -159,10 +158,7 @@ f64 = Type3('f64', TypeApplication_Nullary(None, None))
 A 32-bits IEEE 754 float, of 64 bits width.
 """
 
-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)
+dynamic_array = TypeConstructor_DynamicArray('dynamic_array')
 """
 This is a dynamic length piece of memory.
 
@@ -170,10 +166,7 @@ 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:
-    instance_type_class(InternalPassAsPointer, typ)
-
-static_array = TypeConstructor_StaticArray('static_array', on_create=sa_on_create)
+static_array = TypeConstructor_StaticArray('static_array')
 """
 This is a fixed length piece of memory.
 
@@ -181,10 +174,7 @@ It should be applied with two arguments. It has a compile time
 determined length, and each argument is the same.
 """
 
-def tp_on_create(args: tuple[Type3, ...], typ: Type3) -> None:
-    instance_type_class(InternalPassAsPointer, typ)
-
-tuple_ = TypeConstructor_Tuple('tuple', on_create=tp_on_create)
+tuple_ = TypeConstructor_Tuple('tuple')
 """
 This is a fixed length piece of memory.
 
@@ -192,22 +182,14 @@ It should be applied with zero or more arguments. It has a compile time
 determined length, and each argument can be different.
 """
 
-def fn_on_create(args: tuple[Type3, ...], typ: Type3) -> None:
-    # Not really a pointer; but still a i32
-    # (It's actually a table lookup)
-    instance_type_class(InternalPassAsPointer, typ)
-
-function = TypeConstructor_Function('function', on_create=fn_on_create)
+function = TypeConstructor_Function('function')
 """
 This is a function.
 
 It should be applied with one or more arguments. The last argument is the 'return' type.
 """
 
-def st_on_create(args: tuple[tuple[str, Type3], ...], typ: Type3) -> None:
-    instance_type_class(InternalPassAsPointer, typ)
-
-struct = TypeConstructor_Struct('struct', on_create=st_on_create)
+struct = TypeConstructor_Struct('struct')
 """
 This is like a tuple, but each argument is named, so that developers
 can get and set fields by name.
@@ -218,16 +200,6 @@ b = TypeVariable('b', TypeVariableApplication_Nullary(None, None))
 
 t = TypeConstructorVariable('t')
 
-InternalPassAsPointer = Type3Class('InternalPassAsPointer', (a, ), methods={}, operators={})
-"""
-Internal type class to keep track which types we pass arounds as a pointer.
-"""
-
-# instance_type_class(InternalPassAsPointer, bytes_)
-# instance_type_class(InternalPassAsPointer, static_array)
-# instance_type_class(InternalPassAsPointer, tuple_)
-# instance_type_class(InternalPassAsPointer, struct)
-
 Eq = Type3Class('Eq', (a, ), methods={}, operators={
     '==': [a, a, bool_],
     '!=': [a, a, bool_],
@@ -581,12 +553,21 @@ instance_type_class(Promotable, f32, f64, methods={
 
 Foldable = Type3Class('Foldable', (t, ), methods={
     'sum': [t(a), a],
+    'foldl': [[b, a, b], b, t(a), b],
+    'foldr': [[a, b, b], b, t(a), b],
 }, operators={}, additional_context={
     'sum': [Constraint_TypeClassInstanceExists(NatNum, (a, ))],
 })
 
+instance_type_class(Foldable, dynamic_array, methods={
+    'sum': stdtypes.dynamic_array_sum,
+    'foldl': stdtypes.dynamic_array_foldl,
+    'foldr': stdtypes.dynamic_array_foldr,
+})
 instance_type_class(Foldable, static_array, methods={
     'sum': stdtypes.static_array_sum,
+    'foldl': stdtypes.static_array_foldl,
+    'foldr': stdtypes.static_array_foldr,
 })
 
 bytes_ = dynamic_array(u8)

phasm/runtime.py

@@ -1,11 +1,12 @@
 from . import prelude
+from .stdlib.types import TYPE_INFO_CONSTRUCTED, TYPE_INFO_MAP
 from .type3.routers import NoRouteForTypeException, TypeApplicationRouter
 from .type3.types import IntType3, Type3
 
 
 def calculate_alloc_size_static_array(is_member: bool, args: tuple[Type3, IntType3]) -> int:
     if is_member:
-        return 4
+        return TYPE_INFO_CONSTRUCTED.alloc_size
 
     sa_type, sa_len = args
 
@@ -13,7 +14,7 @@ def calculate_alloc_size_static_array(is_member: bool, args: tuple[Type3, IntTyp
 
 def calculate_alloc_size_tuple(is_member: bool, args: tuple[Type3, ...]) -> int:
     if is_member:
-        return 4
+        return TYPE_INFO_CONSTRUCTED.alloc_size
 
     return sum(
         calculate_alloc_size(x, is_member=True)
@@ -22,7 +23,7 @@ def calculate_alloc_size_tuple(is_member: bool, args: tuple[Type3, ...]) -> int:
 
 def calculate_alloc_size_struct(is_member: bool, args: tuple[tuple[str, Type3], ...]) -> int:
     if is_member:
-        return 4
+        return TYPE_INFO_CONSTRUCTED.alloc_size
 
     return sum(
         calculate_alloc_size(x, is_member=True)
@@ -35,14 +36,9 @@ ALLOC_SIZE_ROUTER.add(prelude.struct, calculate_alloc_size_struct)
 ALLOC_SIZE_ROUTER.add(prelude.tuple_, calculate_alloc_size_tuple)
 
 def calculate_alloc_size(typ: Type3, is_member: bool = False) -> int:
-    if typ in (prelude.u8, prelude.i8, ):
-        return 4 # FIXME: We allocate 4 bytes for every u8 since you load them into an i32
-
-    if typ in (prelude.u32, prelude.i32, prelude.f32, ):
-        return 4
-
-    if typ in (prelude.u64, prelude.i64, prelude.f64, ):
-        return 8
+    typ_info = TYPE_INFO_MAP.get(typ.name)
+    if typ_info is not None:
+        return typ_info.alloc_size
 
     try:
         return ALLOC_SIZE_ROUTER(is_member, typ)
@@ -50,7 +46,7 @@ def calculate_alloc_size(typ: Type3, is_member: bool = False) -> int:
         if is_member:
             # By default, 'boxed' or 'constructed' types are
             # stored as pointers when a member of a struct or tuple
-            return 4
+            return TYPE_INFO_CONSTRUCTED.alloc_size
 
         raise NotImplementedError(typ)
 

phasm/stdlib/types.py

@@ -1,13 +1,63 @@
 """
 stdlib: Standard types that are not wasm primitives
 """
+from typing import Mapping, NamedTuple, Type
+
 from phasm.stdlib import alloc
 from phasm.type3.routers import TypeVariableLookup
 from phasm.type3.types import IntType3, Type3
-from phasm.wasmgenerator import Generator, func_wrapper
+from phasm.wasm import (
+    WasmType,
+    WasmTypeFloat32,
+    WasmTypeFloat64,
+    WasmTypeInt32,
+    WasmTypeInt64,
+    WasmTypeNone,
+)
+from phasm.wasmgenerator import Generator, VarType_Base, func_wrapper
+from phasm.wasmgenerator import VarType_f32 as f32
+from phasm.wasmgenerator import VarType_f64 as f64
 from phasm.wasmgenerator import VarType_i32 as i32
 from phasm.wasmgenerator import VarType_i64 as i64
 
+TypeInfo = NamedTuple('TypeInfo', [
+    # Name of the type
+    ('typ', str, ),
+    # What WebAssembly type to use when passing this value around
+    # For example in function arguments
+    ('wasm_type', Type[WasmType]),
+    # What WebAssembly function to use when loading a value from memory
+    ('wasm_load_func', str),
+    # What WebAssembly function to use when storing a value to memory
+    ('wasm_store_func', str),
+    # When storing this value in memory, how many bytes do we use?
+    # Only valid for non-constructed types, see calculate_alloc_size
+    # Should match wasm_load_func / wasm_store_func
+    ('alloc_size', int),
+])
+
+TYPE_INFO_MAP: Mapping[str, TypeInfo] = {
+    'none': TypeInfo('none', WasmTypeNone, 'nop', 'nop', 0),
+    'bool': TypeInfo('bool', WasmTypeInt32, 'i32.load8_u', 'i32.store8', 1),
+
+    'u8': TypeInfo('u8', WasmTypeInt32, 'i32.load8_u', 'i32.store8', 1),
+    'i8': TypeInfo('i8', WasmTypeInt32, 'i32.load8_s', 'i32.store8', 1),
+
+    'u32': TypeInfo('u32', WasmTypeInt32, 'i32.load', 'i32.store', 4),
+    'u64': TypeInfo('u64', WasmTypeInt64, 'i64.load', 'i64.store', 8),
+    'i32': TypeInfo('i32', WasmTypeInt32, 'i32.load', 'i32.store', 4),
+    'i64': TypeInfo('i64', WasmTypeInt64, 'i64.load', 'i64.store', 8),
+    'f32': TypeInfo('f32', WasmTypeFloat32, 'f32.load', 'f32.store', 4),
+    'f64': TypeInfo('f64', WasmTypeFloat64, 'f64.load', 'f64.store', 8),
+    'ptr': TypeInfo('ptr', WasmTypeInt32, 'i32.load', 'i32.store', 4),
+}
+
+# By default, constructed types are passed as pointers
+# NOTE: ALLOC SIZE HERE DOES NOT WORK FOR CONSTRUCTED TYPES
+# USE runtime.calculate_alloc_size FOR ACCURATE RESULTS
+# Functions count as constructed types - even though they are
+# not memory pointers but table addresses instead.
+TYPE_INFO_CONSTRUCTED = TypeInfo('t a', WasmTypeInt32, 'i32.load', 'i32.store', 4)
 
 @func_wrapper()
 def __alloc_bytes__(g: Generator, length: i32) -> i32:
@@ -1011,12 +1061,16 @@ def dynamic_array_sized_len(g: Generator, tv_map: TypeVariableLookup) -> None:
     # 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)
+def static_array_sized_len(g: Generator, tvl: TypeVariableLookup) -> None:
+    tv_map, tc_map = tvl
 
+    tvn_map = {
+        x.name: y
+        for x, y in tv_map.items()
+    }
+
+    sa_len = tvn_map['a*']
+    assert isinstance(sa_len, IntType3)
     g.i32.const(sa_len.value)
 
 ## ###
@@ -1089,35 +1143,32 @@ def f32_f64_demote(g: Generator, tv_map: TypeVariableLookup) -> None:
     del tv_map
     g.f32.demote_f64()
 
-def static_array_sum(g: Generator, tv_map: TypeVariableLookup) -> None:
-    assert len(tv_map) == 1
-    sa_type, sa_len = next(iter(tv_map.values()))
+## ###
+## Foldable
+
+def dynamic_array_sum(g: Generator, tvl: TypeVariableLookup) -> None:
+    raise NotImplementedError
+
+def static_array_sum(g: Generator, tvl: TypeVariableLookup) -> None:
+    tv_map, tc_map = tvl
+
+    tvn_map = {
+        x.name: y
+        for x, y in tv_map.items()
+    }
+
+    sa_type = tvn_map['a']
+    sa_len = tvn_map['a*']
+
     assert isinstance(sa_type, Type3)
     assert isinstance(sa_len, IntType3)
 
     if sa_len.value < 1:
         raise NotImplementedError('Default value in case sum is empty')
 
-    # FIXME: We should probably use LOAD_STORE_TYPE_MAP for this?
-    mtyp_map = {
-        'u32': 'i32',
-        'u64': 'i64',
-        'i32': 'i32',
-        'i64': 'i64',
-        'f32': 'f32',
-        'f64': 'f64',
-    }
-
-    # FIXME: We should probably use calc_alloc_size for this?
-    type_var_size_map = {
-        'u32': 4,
-        'u64': 8,
-        'i32': 4,
-        'i64': 8,
-        'f32': 4,
-        'f64': 8,
-    }
+    sa_type_info = TYPE_INFO_MAP.get(sa_type.name, TYPE_INFO_CONSTRUCTED)
 
+    # FIXME: This breaks when users start implementing their own NatNum classes
     type_var_add_generator = {
         'u32': u32_natnum_add,
         'u64': u64_natnum_add,
@@ -1126,11 +1177,6 @@ def static_array_sum(g: Generator, tv_map: TypeVariableLookup) -> None:
         'f32': f32_natnum_add,
         'f64': f64_natnum_add,
     }
-
-    # By default, constructed types are passed as pointers
-    # FIXME: We don't know what add function to call
-    sa_type_mtyp = mtyp_map.get(sa_type.name, 'i32')
-    sa_type_alloc_size = type_var_size_map.get(sa_type.name, 4)
     sa_type_add_gen = type_var_add_generator[sa_type.name]
 
     # Definitions
@@ -1149,7 +1195,7 @@ def static_array_sum(g: Generator, tv_map: TypeVariableLookup) -> None:
     # Stack: []
     g.nop(comment='Calculate address at which to stop looping')
     g.local.get(sum_adr)
-    g.i32.const(sa_len.value * sa_type_alloc_size)
+    g.i32.const(sa_len.value * sa_type_info.alloc_size)
     g.i32.add()
     g.local.set(sum_stop)
 
@@ -1157,30 +1203,30 @@ def static_array_sum(g: Generator, tv_map: TypeVariableLookup) -> None:
     # Stack: [] -> [sum]
     g.nop(comment='Get the first array value as starting point')
     g.local.get(sum_adr)
-    g.add_statement(f'{sa_type_mtyp}.load')
+    g.add_statement(sa_type_info.wasm_load_func)
 
     # Since we did the first one, increase adr
     # adr = adr + sa_type_alloc_size
     # Stack: [sum] -> [sum]
     g.local.get(sum_adr)
-    g.i32.const(sa_type_alloc_size)
+    g.i32.const(sa_type_info.alloc_size)
     g.i32.add()
     g.local.set(sum_adr)
 
     if sa_len.value > 1:
-        with g.loop(params=[sa_type_mtyp], result=sa_type_mtyp):
+        with g.loop(params=[sa_type_info.wasm_type().to_wat()], result=sa_type_info.wasm_type().to_wat()):
             # sum = sum + *adr
             # Stack: [sum] -> [sum + *adr]
             g.nop(comment='Add array value')
             g.local.get(sum_adr)
-            g.add_statement(f'{sa_type_mtyp}.load')
-            sa_type_add_gen(g, {})
+            g.add_statement(sa_type_info.wasm_load_func)
+            sa_type_add_gen(g, ({}, {}, ))
 
             # adr = adr + sa_type_alloc_size
             # Stack: [sum] -> [sum]
             g.nop(comment='Calculate address of the next value')
             g.local.get(sum_adr)
-            g.i32.const(sa_type_alloc_size)
+            g.i32.const(sa_type_info.alloc_size)
             g.i32.add()
             g.local.tee(sum_adr)
 
@@ -1193,3 +1239,396 @@ def static_array_sum(g: Generator, tv_map: TypeVariableLookup) -> None:
 
     g.nop(comment=f'Completed sum for {sa_type.name}[{sa_len.value}]')
     # End result: [sum]
+
+def dynamic_array_foldl(g: Generator, tvl: TypeVariableLookup) -> None:
+    tv_map, tc_map = tvl
+
+    tvn_map = {
+        x.name: y
+        for x, y in tv_map.items()
+    }
+
+    sa_type = tvn_map['a']
+    res_type = tvn_map['b']
+
+    assert isinstance(sa_type, Type3)
+    assert isinstance(res_type, Type3)
+
+    # FIXME: We should probably use LOAD_STORE_TYPE_MAP for this?
+    load_map = {
+        'u8': 'i32.load8_u',
+        'u32': 'i32.load',
+        'u64': 'i64.load',
+        'i8': 'i32.load8_s',
+        'i32': 'i32.load',
+        'i64': 'i64.load',
+        'f32': 'f32.load',
+        'f64': 'f64.load',
+    }
+    mtyp_map = {
+        'u32': 'i32',
+        'u64': 'i64',
+        'i32': 'i32',
+        'i64': 'i64',
+        'f32': 'f32',
+        'f64': 'f64',
+    }
+    mtyp_f_map: dict[str, type[VarType_Base]] = {
+        'i32': i32,
+        'i64': i64,
+        'f32': f32,
+        'f64': f64,
+    }
+
+    # FIXME: We should probably use calc_alloc_size for this?
+    type_var_size_map = {
+        'u8': 1,
+        'u32': 4,
+        'u64': 8,
+        'i8': 1,
+        'i32': 4,
+        'i64': 8,
+        'f32': 4,
+        'f64': 8,
+    }
+
+    # By default, constructed types are passed as pointers
+    # FIXME: We don't know what add function to call
+    sa_type_load = load_map.get(sa_type.name, 'i32')
+    sa_type_mtyp = mtyp_map.get(sa_type.name, 'i32')
+    sa_type_alloc_size = type_var_size_map.get(sa_type.name, 4)
+    res_type_mtyp = mtyp_map.get(res_type.name, 'i32')
+    res_type_mtyp_f = mtyp_f_map[res_type_mtyp]
+
+    # Definitions
+    fold_adr = g.temp_var(i32('fold_adr'))
+    fold_stop = g.temp_var(i32('fold_stop'))
+    fold_init = g.temp_var(res_type_mtyp_f('fold_init'))
+    fold_func = g.temp_var(i32('fold_func'))
+    fold_len = g.temp_var(i32('fold_len'))
+
+    with g.block(params=['i32', res_type_mtyp, 'i32'], result=res_type_mtyp, comment=f'foldl a={sa_type.name} b={res_type.name}'):
+        # Stack: [fn*, b, sa*] -> [fn*, b]
+        g.local.tee(fold_adr)  # Store address, but also keep it for loading the length
+        g.i32.load()  # Load the length
+        g.local.set(fold_len)  # Store the length
+
+        # Stack: [fn*, b] -> [fn*]
+        g.local.set(fold_init)
+        # Stack: [fn*] -> []
+        g.local.set(fold_func)
+
+        # Stack: [] -> [b]
+        g.nop(comment='No applications if array is empty')
+        g.local.get(fold_init)
+        g.local.get(fold_len)
+        g.i32.eqz() # If the array is empty
+        g.br_if(0)  # Then the base value is the result
+
+        # Stack: [b] -> [b]  ; fold_adr=fold_adr + 4
+        g.nop(comment='Skip the header')
+        g.local.get(fold_adr)
+        g.i32.const(4)
+        g.i32.add()
+        g.local.set(fold_adr)
+
+        # Stack: [b] -> [b]
+        g.nop(comment='Apply the first function call')
+        g.local.get(fold_adr)
+        g.add_statement(sa_type_load)
+        g.local.get(fold_func)
+        g.add_statement(f'call_indirect (param {res_type_mtyp} {sa_type_mtyp}) (result {res_type_mtyp})')
+
+        # Stack: [b] -> [b]
+        g.nop(comment='No loop if there is only one item')
+        g.local.get(fold_len)
+        g.i32.const(1)
+        g.i32.eq()
+        g.br_if(0)  # just one value, don't need to loop
+
+        # Stack: [b] -> [b]  ; fold_stop=fold_adr + (sa_len.value * sa_type_alloc_size)
+        g.nop(comment='Calculate address at which to stop looping')
+        g.local.get(fold_adr)
+        g.local.get(fold_len)
+        g.i32.const(sa_type_alloc_size)
+        g.i32.mul()
+        g.i32.add()
+        g.local.set(fold_stop)
+
+        # Stack: [b] -> [b]  ; fold_adr = fold_adr + sa_type_alloc_size
+        g.nop(comment='Calculate address of the next value')
+        g.local.get(fold_adr)
+        g.i32.const(sa_type_alloc_size)
+        g.i32.add()
+        g.local.set(fold_adr)
+
+        with g.loop(params=[res_type_mtyp], result=res_type_mtyp):
+            # Stack: [b] -> [b]
+            g.nop(comment='Apply function call')
+            g.local.get(fold_adr)
+            g.add_statement(sa_type_load)
+            g.local.get(fold_func)
+            g.add_statement(f'call_indirect (param {res_type_mtyp} {sa_type_mtyp}) (result {res_type_mtyp})')
+
+            # Stack: [b] -> [b]  ; fold_adr = fold_adr + sa_type_alloc_size
+            g.nop(comment='Calculate address of the next value')
+            g.local.get(fold_adr)
+            g.i32.const(sa_type_alloc_size)
+            g.i32.add()
+            g.local.tee(fold_adr)
+
+            # loop if adr > stop
+            # Stack: [b] -> [b]
+            g.nop(comment='Check if address exceeds array bounds')
+            g.local.get(fold_stop)
+            g.i32.lt_u()
+            g.br_if(0)
+
+    # Stack: [b]
+
+def static_array_foldl(g: Generator, tvl: TypeVariableLookup) -> None:
+    tv_map, tc_map = tvl
+
+    tvn_map = {
+        x.name: y
+        for x, y in tv_map.items()
+    }
+
+    sa_type = tvn_map['a']
+    sa_len = tvn_map['a*']
+    res_type = tvn_map['b']
+
+    assert isinstance(sa_type, Type3)
+    assert isinstance(sa_len, IntType3)
+    assert isinstance(res_type, Type3)
+
+    # FIXME: We should probably use LOAD_STORE_TYPE_MAP for this?
+    mtyp_map = {
+        'u32': 'i32',
+        'u64': 'i64',
+        'i32': 'i32',
+        'i64': 'i64',
+        'f32': 'f32',
+        'f64': 'f64',
+    }
+    mtyp_f_map: dict[str, type[VarType_Base]] = {
+        'i32': i32,
+        'i64': i64,
+        'f32': f32,
+        'f64': f64,
+    }
+
+    # FIXME: We should probably use calc_alloc_size for this?
+    type_var_size_map = {
+        'u32': 4,
+        'u64': 8,
+        'i32': 4,
+        'i64': 8,
+        'f32': 4,
+        'f64': 8,
+    }
+
+    # By default, constructed types are passed as pointers
+    # FIXME: We don't know what add function to call
+    sa_type_mtyp = mtyp_map.get(sa_type.name, 'i32')
+    sa_type_alloc_size = type_var_size_map.get(sa_type.name, 4)
+    res_type_mtyp = mtyp_map.get(res_type.name, 'i32')
+    res_type_mtyp_f = mtyp_f_map[res_type_mtyp]
+
+    # Definitions
+    fold_adr = g.temp_var(i32('fold_adr'))
+    fold_stop = g.temp_var(i32('fold_stop'))
+    fold_init = g.temp_var(res_type_mtyp_f('fold_init'))
+    fold_func = g.temp_var(i32('fold_func'))
+
+    with g.block(params=['i32', res_type_mtyp, 'i32'], result=res_type_mtyp, comment=f'foldl a={sa_type.name} a*={sa_len.value} b={res_type.name}'):
+        # Stack: [fn*, b, sa*] -> [fn*, b]
+        g.local.set(fold_adr)
+        # Stack: [fn*, b] -> [fn*]
+        g.local.set(fold_init)
+        # Stack: [fn*] -> []
+        g.local.set(fold_func)
+
+        if sa_len.value < 1:
+            g.local.get(fold_init)
+            return
+
+        # Stack: [] -> [b]
+        g.nop(comment='Apply the first function call')
+        g.local.get(fold_init)
+        g.local.get(fold_adr)
+        g.add_statement(f'{sa_type_mtyp}.load')
+        g.local.get(fold_func)
+        g.add_statement(f'call_indirect (param {res_type_mtyp} {sa_type_mtyp}) (result {res_type_mtyp})')
+
+        if sa_len.value > 1:
+            # Stack: [b] -> [b]  ; fold_stop=fold_adr + (sa_len.value * sa_type_alloc_size)
+            g.nop(comment='Calculate address at which to stop looping')
+            g.local.get(fold_adr)
+            g.i32.const(sa_len.value * sa_type_alloc_size)
+            g.i32.add()
+            g.local.set(fold_stop)
+
+            # Stack: [b] -> [b]  ; fold_adr = fold_adr + sa_type_alloc_size
+            g.nop(comment='Calculate address of the next value')
+            g.local.get(fold_adr)
+            g.i32.const(sa_type_alloc_size)
+            g.i32.add()
+            g.local.set(fold_adr)
+
+            with g.loop(params=[res_type_mtyp], result=res_type_mtyp):
+                # Stack: [b] -> [b]
+                g.nop(comment='Apply function call')
+                g.local.get(fold_adr)
+                g.add_statement(f'{sa_type_mtyp}.load')
+                g.local.get(fold_func)
+                g.add_statement(f'call_indirect (param {res_type_mtyp} {sa_type_mtyp}) (result {res_type_mtyp})')
+
+                # Stack: [b] -> [b]  ; fold_adr = fold_adr + sa_type_alloc_size
+                g.nop(comment='Calculate address of the next value')
+                g.local.get(fold_adr)
+                g.i32.const(sa_type_alloc_size)
+                g.i32.add()
+                g.local.tee(fold_adr)
+
+                # loop if adr > stop
+                # Stack: [b] -> [b]
+                g.nop(comment='Check if address exceeds array bounds')
+                g.local.get(fold_stop)
+                g.i32.lt_u()
+                g.br_if(0)
+        # else: just one value, don't need to loop
+
+    # Stack: [b]
+
+def dynamic_array_foldr(g: Generator, tvl: TypeVariableLookup) -> None:
+    raise NotImplementedError
+
+def static_array_foldr(g: Generator, tvl: TypeVariableLookup) -> None:
+    tv_map, tc_map = tvl
+
+    tvn_map = {
+        x.name: y
+        for x, y in tv_map.items()
+    }
+
+    sa_type = tvn_map['a']
+    sa_len = tvn_map['a*']
+    res_type = tvn_map['b']
+
+    assert isinstance(sa_type, Type3)
+    assert isinstance(sa_len, IntType3)
+    assert isinstance(res_type, Type3)
+
+    # FIXME: We should probably use LOAD_STORE_TYPE_MAP for this?
+    mtyp_map = {
+        'u32': 'i32',
+        'u64': 'i64',
+        'i32': 'i32',
+        'i64': 'i64',
+        'f32': 'f32',
+        'f64': 'f64',
+    }
+    mtyp_f_map: dict[str, type[VarType_Base]] = {
+        'i32': i32,
+        'i64': i64,
+        'f32': f32,
+        'f64': f64,
+    }
+
+    # FIXME: We should probably use calc_alloc_size for this?
+    type_var_size_map = {
+        'u32': 4,
+        'u64': 8,
+        'i32': 4,
+        'i64': 8,
+        'f32': 4,
+        'f64': 8,
+    }
+
+    # By default, constructed types are passed as pointers
+    sa_type_mtyp = mtyp_map.get(sa_type.name, 'i32')
+    sa_type_alloc_size = type_var_size_map.get(sa_type.name, 4)
+    res_type_mtyp = mtyp_map.get(res_type.name, 'i32')
+    res_type_mtyp_f = mtyp_f_map[res_type_mtyp]
+
+    # Definitions
+    fold_adr = g.temp_var(i32('fold_adr'))
+    fold_stop = g.temp_var(i32('fold_stop'))
+    fold_tmp = g.temp_var(res_type_mtyp_f('fold_tmp'))
+    fold_func = g.temp_var(i32('fold_func'))
+
+    with g.block(params=['i32', res_type_mtyp, 'i32'], result=res_type_mtyp, comment=f'foldr a={sa_type.name} a*={sa_len.value} b={res_type.name}'):
+        # Stack: [fn*, b, sa*] -> [fn*, b]  ; fold_adr=fn*, fold_tmp=b, fold_func=fn*
+        g.local.set(fold_adr)
+        # Stack: [fn*, b] -> [fn*]
+        g.local.set(fold_tmp)
+        # Stack: [fn*] -> []
+        g.local.set(fold_func)
+
+        if sa_len.value < 1:
+            g.local.get(fold_tmp)
+            return
+
+        # Stack: [] -> []  ; fold_stop=fold_adr
+        g.nop(comment='Calculate address at which to stop looping')
+        g.local.get(fold_adr)
+        g.local.set(fold_stop)
+
+        # Stack: [] -> []  ; fold_adr=fold_adr + (sa_len.value - 1) * sa_type_alloc_size
+        g.nop(comment='Calculate address at which to stop looping')
+        g.local.get(fold_adr)
+        g.i32.const((sa_len.value - 1) * sa_type_alloc_size)
+        g.i32.add()
+        g.local.set(fold_adr)
+
+        # Stack: [] -> [b]
+        g.nop(comment='Get the init value and first array value as starting point')
+        g.local.get(fold_adr)
+        g.add_statement(f'{sa_type_mtyp}.load')
+        g.local.get(fold_tmp)
+        g.local.get(fold_func)
+        g.add_statement(f'call_indirect (param {sa_type_mtyp} {res_type_mtyp}) (result {res_type_mtyp})')
+
+        if sa_len.value > 1:
+            # Stack: [b] -> [b]  ; fold_adr = fold_adr - sa_type_alloc_size
+            g.nop(comment='Calculate address of the next value')
+            g.local.get(fold_adr)
+            g.i32.const(sa_type_alloc_size)
+            g.i32.sub()
+            g.local.set(fold_adr)
+
+            with g.loop(params=[res_type_mtyp], result=res_type_mtyp):
+                g.nop(comment='Apply function call')
+
+                # Stack [b] since we don't have proper stack switching opcodes
+                # Stack: [b] -> []
+                g.local.set(fold_tmp)
+
+                # Stack: [] -> [a]
+                g.local.get(fold_adr)
+                g.add_statement(f'{sa_type_mtyp}.load')
+
+                # Stack [a] -> [a, b]
+                g.local.get(fold_tmp)
+
+                # Stack [a, b] -> [b]
+                g.local.get(fold_func)
+                g.add_statement(f'call_indirect (param {sa_type_mtyp} {res_type_mtyp}) (result {res_type_mtyp})')
+
+                # Stack: [b] -> [b]  ; fold_adr = fold_adr - sa_type_alloc_size
+                g.nop(comment='Calculate address of the next value')
+                g.local.get(fold_adr)
+                g.i32.const(sa_type_alloc_size)
+                g.i32.sub()
+                g.local.tee(fold_adr)
+
+                # loop if adr >= stop
+                # Stack: [b] -> [b]
+                g.nop(comment='Check if address exceeds array bounds')
+                g.local.get(fold_stop)
+                g.i32.ge_u()
+                g.br_if(0)
+        # else: just one value, don't need to loop
+
+    # Stack: [b]

phasm/type3/constraints.py

@@ -183,7 +183,7 @@ class SameTypeArgumentConstraint(ConstraintBase):
         self.arg_var = arg_var
 
     def check(self) -> CheckResult:
-        if self.tc_var.resolve_as is None or self.arg_var.resolve_as is None:
+        if self.tc_var.resolve_as is None:
             return RequireTypeSubstitutes()
 
         tc_typ = self.tc_var.resolve_as
@@ -200,12 +200,16 @@ class SameTypeArgumentConstraint(ConstraintBase):
             # So we can let the MustImplementTypeClassConstraint handle it.
             return None
 
+        if isinstance(tc_typ.application, TypeApplication_Type):
+            return [SameTypeConstraint(
+                tc_typ.application.arguments[0],
+                self.arg_var,
+                comment=self.comment,
+            )]
+
         # FIXME: This feels sketchy. Shouldn't the type variable
         # have the exact same number as arguments?
         if isinstance(tc_typ.application, TypeApplication_TypeInt):
-            if tc_typ.application.arguments[0] == arg_typ:
-                return None
-
             return [SameTypeConstraint(
                 tc_typ.application.arguments[0],
                 self.arg_var,
@@ -346,14 +350,10 @@ class MustImplementTypeClassConstraint(ConstraintBase):
     __slots__ = ('context', 'type_class3', 'types', )
 
     context: Context
-    type_class3: Union[str, Type3Class]
+    type_class3: Type3Class
     types: list[Type3OrPlaceholder]
 
-    DATA = {
-        'dynamic_array': {'Foldable'},
-    }
-
-    def __init__(self, context: Context, type_class3: Union[str, Type3Class], typ_list: list[Type3OrPlaceholder], comment: Optional[str] = None) -> None:
+    def __init__(self, context: Context, type_class3: Type3Class, typ_list: list[Type3OrPlaceholder], comment: Optional[str] = None) -> None:
         super().__init__(comment=comment)
 
         self.context = context
@@ -381,13 +381,9 @@ class MustImplementTypeClassConstraint(ConstraintBase):
 
         assert len(typ_list) == len(self.types)
 
-        if isinstance(self.type_class3, Type3Class):
-            key = (self.type_class3, tuple(typ_list), )
-            if key in self.context.type_class_instances_existing:
-                return None
-        else:
-            if self.type_class3 in self.__class__.DATA.get(typ_list[0].name, set()):
-                return None
+        key = (self.type_class3, tuple(typ_list), )
+        if key in self.context.type_class_instances_existing:
+            return None
 
         typ_cls_name = self.type_class3 if isinstance(self.type_class3, str) else self.type_class3.name
         typ_name_list = ' '.join(x.name for x in typ_list)

phasm/type3/constraintsgenerator.py

@@ -202,6 +202,10 @@ def _expression_function_call(
             yield SameTypeConstraint(sig_part, arg_placeholders[arg_expr], comment=comment)
             continue
 
+        if isinstance(sig_part, FunctionArgument):
+            yield SameTypeConstraint(func_var_map[sig_part], arg_placeholders[arg_expr], comment=comment)
+            continue
+
         raise NotImplementedError(sig_part)
     return
 
@@ -265,19 +269,6 @@ def expression(ctx: Context, inp: ourlang.Expression, phft: PlaceholderForType)
             comment=f'The type of a struct member reference is the same as the type of struct member {inp.struct_type3.name}.{inp.member}')
         return
 
-    if isinstance(inp, ourlang.Fold):
-        base_phft = PlaceholderForType([inp.base])
-        iter_phft = PlaceholderForType([inp.iter])
-
-        yield from expression(ctx, inp.base, base_phft)
-        yield from expression(ctx, inp.iter, iter_phft)
-
-        yield SameTypeConstraint(inp.func.posonlyargs[0].type3, inp.func.returns_type3, base_phft, phft,
-            comment='foldl :: Foldable t => (b -> a -> b) -> b -> t a -> b')
-        yield MustImplementTypeClassConstraint(ctx, 'Foldable', [iter_phft])
-
-        return
-
     raise NotImplementedError(expression, inp)
 
 def statement_return(ctx: Context, fun: ourlang.Function, inp: ourlang.StatementReturn) -> ConstraintGenerator:

phasm/type3/routers.py

@@ -3,6 +3,7 @@ from typing import Any, Callable
 from .functions import (
     TypeConstructorVariable,
     TypeVariable,
+    TypeVariableApplication_Nullary,
     TypeVariableApplication_Unary,
 )
 from .typeclasses import Type3ClassArgs
@@ -60,7 +61,10 @@ class TypeApplicationRouter[S, R]:
 
         raise NoRouteForTypeException(arg0, typ)
 
-TypeVariableLookup = dict[TypeVariable, tuple[KindArgument, ...]]
+TypeVariableLookup = tuple[
+    dict[TypeVariable, KindArgument],
+    dict[TypeConstructorVariable, TypeConstructor_Base[Any]],
+]
 
 class TypeClassArgsRouter[S, R]:
     """
@@ -95,11 +99,12 @@ class TypeClassArgsRouter[S, R]:
 
     def __call__(self, arg0: S, tv_map: dict[TypeVariable, Type3]) -> R:
         key: list[Type3 | TypeConstructor_Base[Any]] = []
-        arguments: TypeVariableLookup = {}
+        arguments: TypeVariableLookup = (dict(tv_map), {}, )
 
         for tc_arg in self.args:
             if isinstance(tc_arg, TypeVariable):
                 key.append(tv_map[tc_arg])
+                arguments[0][tc_arg] = tv_map[tc_arg]
                 continue
 
             for tvar, typ in tv_map.items():
@@ -108,16 +113,24 @@ class TypeClassArgsRouter[S, R]:
                     continue
 
                 key.append(typ.application.constructor)
+                arguments[1][tc_arg] = typ.application.constructor
 
                 if isinstance(tvar.application, TypeVariableApplication_Unary):
                     if isinstance(typ.application, TypeApplication_Type):
-                        arguments[tvar.application.arguments] = typ.application.arguments
+                        da_type, = typ.application.arguments
+                        sa_type_tv = tvar.application.arguments
+                        arguments[0][sa_type_tv] = da_type
                         continue
 
                     # FIXME: This feels sketchy. Shouldn't the type variable
                     # have the exact same number as arguments?
                     if isinstance(typ.application, TypeApplication_TypeInt):
-                        arguments[tvar.application.arguments] = typ.application.arguments
+                        sa_type, sa_len = typ.application.arguments
+                        sa_type_tv = tvar.application.arguments
+                        sa_len_tv = TypeVariable(sa_type_tv.name + '*', TypeVariableApplication_Nullary(None, None))
+
+                        arguments[0][sa_type_tv] = sa_type
+                        arguments[0][sa_len_tv] = sa_len
                         continue
 
                 raise NotImplementedError(tvar.application, typ.application)

phasm/type3/typeclasses.py

@@ -1,4 +1,4 @@
-from typing import Dict, Iterable, List, Mapping, Optional, Union
+from typing import Dict, Iterable, List, Mapping, Optional
 
 from .functions import (
     Constraint_TypeClassInstanceExists,
@@ -42,8 +42,8 @@ class Type3Class:
             self,
             name: str,
             args: Type3ClassArgs,
-            methods: Mapping[str, Iterable[Union[Type3, TypeVariable]]],
-            operators: Mapping[str, Iterable[Union[Type3, TypeVariable]]],
+            methods: Mapping[str, Iterable[Type3 | TypeVariable | list[Type3 | TypeVariable]]],
+            operators: Mapping[str, Iterable[Type3 | TypeVariable | list[Type3 | TypeVariable]]],
             inherited_classes: Optional[List['Type3Class']] = None,
             additional_context: Optional[Mapping[str, Iterable[ConstraintBase]]] = None,
         ) -> None:
@@ -71,19 +71,23 @@ class Type3Class:
         return self.name
 
 def _create_signature(
-        method_arg_list: Iterable[Type3 | TypeVariable],
+        method_arg_list: Iterable[Type3 | TypeVariable | list[Type3 | TypeVariable]],
         type_class3: Type3Class,
     ) -> FunctionSignature:
     context = TypeVariableContext()
     if not isinstance(type_class3.args[0], TypeConstructorVariable):
         context.constraints.append(Constraint_TypeClassInstanceExists(type_class3, type_class3.args))
 
-    signature_args: list[Type3 | TypeVariable] = []
+    signature_args: list[Type3 | TypeVariable | list[Type3 | TypeVariable]] = []
     for method_arg in method_arg_list:
         if isinstance(method_arg, Type3):
             signature_args.append(method_arg)
             continue
 
+        if isinstance(method_arg, list):
+            signature_args.append(method_arg)
+            continue
+
         if isinstance(method_arg, TypeVariable):
             type_constructor = method_arg.application.constructor
             if type_constructor is None:

phasm/type3/types.py

@@ -3,7 +3,6 @@ Contains the final types for use in Phasm, as well as construtors.
 """
 from typing import (
     Any,
-    Callable,
     Hashable,
     Self,
     Tuple,
@@ -141,27 +140,21 @@ class TypeConstructor_Base[T]:
     """
     Base class for type construtors
     """
-    __slots__ = ('name', 'on_create', '_cache', )
+    __slots__ = ('name', '_cache', )
 
     name: str
     """
     The name of the type constructor
     """
 
-    on_create: Callable[[T, Type3], None]
-    """
-    Who to let know if a type is created
-    """
-
     _cache: dict[T, Type3]
     """
     When constructing a type with the same arguments,
     it should produce the exact same result.
     """
 
-    def __init__(self, name: str, on_create: Callable[[T, Type3], None]) -> None:
+    def __init__(self, name: str) -> None:
         self.name = name
-        self.on_create = on_create
 
         self._cache = {}
 
@@ -188,7 +181,6 @@ class TypeConstructor_Base[T]:
         result = self._cache.get(key, None)
         if result is None:
             self._cache[key] = result = Type3(self.make_name(key), self.make_application(key))
-            self.on_create(key, result)
 
         return result
 
@@ -292,7 +284,6 @@ class TypeConstructor_Struct(TypeConstructor_Base[tuple[tuple[str, Type3], ...]]
 
     def __call__(self, name: str, args: tuple[tuple[str, Type3], ...]) -> Type3:
         result = Type3(name, self.make_application(args))
-        self.on_create(args, result)
         return result
 
 class TypeApplication_Struct(TypeApplication_Base[TypeConstructor_Struct, tuple[tuple[str, Type3], ...]]):

phasm/wasmgenerator.py

@@ -170,11 +170,12 @@ class Generator_Local:
         self.generator.add_statement('local.tee', variable.name_ref, comment=comment)
 
 class GeneratorBlock:
-    def __init__(self, generator: 'Generator', name: str, params: Iterable[str] = (), result: str | None = None) -> None:
+    def __init__(self, generator: 'Generator', name: str, params: Iterable[str] = (), result: str | None = None, comment: str | None = None) -> None:
         self.generator = generator
         self.name = name
         self.params = params
         self.result = result
+        self.comment = comment
 
     def __enter__(self) -> None:
         stmt = self.name
@@ -186,7 +187,7 @@ class GeneratorBlock:
         if self.result:
             stmt = f'{stmt} (result {self.result})'
 
-        self.generator.add_statement(stmt)
+        self.generator.add_statement(stmt, comment=self.comment)
 
     def __exit__(self, exc_type: Any, exc_value: Any, traceback: Any) -> None:
         if not exc_type:
@@ -208,7 +209,7 @@ class Generator:
         # 2.4.5 Control Instructions
         self.nop = functools.partial(self.add_statement, 'nop')
         self.unreachable = functools.partial(self.add_statement, 'unreachable')
-        # block
+        self.block = functools.partial(GeneratorBlock, self, 'block')
         self.loop = functools.partial(GeneratorBlock, self, 'loop')
         self.if_ = functools.partial(GeneratorBlock, self, 'if')
         # br

tests/integration/helpers.py

@@ -1,3 +1,4 @@
+import os
 import struct
 import sys
 from typing import Any, Generator, Iterable, List, TextIO, Union
@@ -10,6 +11,7 @@ from phasm.runtime import (
     calculate_alloc_size_struct,
     calculate_alloc_size_tuple,
 )
+from phasm.stdlib.types import TYPE_INFO_CONSTRUCTED, TYPE_INFO_MAP
 from phasm.type3 import types as type3types
 from phasm.type3.routers import NoRouteForTypeException, TypeApplicationRouter
 
@@ -35,26 +37,39 @@ class Suite:
     def __init__(self, code_py: str) -> None:
         self.code_py = code_py
 
-    def run_code(self, *args: Any, runtime: str = 'wasmtime', func_name: str = 'testEntry', imports: runners.Imports = None, do_format_check: bool = True) -> Any:
+    def run_code(
+            self,
+            *args: Any,
+            runtime: str = 'wasmtime',
+            func_name: str = 'testEntry',
+            imports: runners.Imports = None,
+            do_format_check: bool = True,
+            verbose: bool | None = None,
+        ) -> Any:
         """
         Compiles the given python code into wasm and
         then runs it
 
         Returned is an object with the results set
         """
+        if verbose is None:
+            verbose = bool(os.environ.get('VERBOSE'))
+
         class_ = RUNNER_CLASS_MAP[runtime]
 
         runner = class_(self.code_py)
 
-        write_header(sys.stderr, 'Phasm')
-        runner.dump_phasm_code(sys.stderr)
+        if verbose:
+            write_header(sys.stderr, 'Phasm')
+            runner.dump_phasm_code(sys.stderr)
 
-        runner.parse()
+        runner.parse(verbose=verbose)
         runner.compile_ast()
         runner.compile_wat()
 
-        write_header(sys.stderr, 'Assembly')
-        runner.dump_wasm_wat(sys.stderr)
+        if verbose:
+            write_header(sys.stderr, 'Assembly')
+            runner.dump_wasm_wat(sys.stderr)
 
         runner.interpreter_setup()
         runner.interpreter_load(imports)
@@ -69,8 +84,9 @@ class Suite:
 
         wasm_args: List[Union[float, int]] = []
         if args:
-            write_header(sys.stderr, 'Memory (pre alloc)')
-            runner.interpreter_dump_memory(sys.stderr)
+            if verbose:
+                write_header(sys.stderr, 'Memory (pre alloc)')
+                runner.interpreter_dump_memory(sys.stderr)
 
             for arg, arg_typ in zip(args, func_args, strict=True):
                 if arg_typ in (prelude.u8, prelude.u32, prelude.u64, ):
@@ -94,8 +110,9 @@ class Suite:
                 except NoRouteForTypeException:
                     raise NotImplementedError(arg_typ, arg)
 
-        write_header(sys.stderr, 'Memory (pre run)')
-        runner.interpreter_dump_memory(sys.stderr)
+        if verbose:
+            write_header(sys.stderr, 'Memory (pre run)')
+            runner.interpreter_dump_memory(sys.stderr)
 
         result = SuiteResult()
         result.returned_value = runner.call(func_name, *wasm_args)
@@ -106,8 +123,9 @@ class Suite:
             result.returned_value,
         )
 
-        write_header(sys.stderr, 'Memory (post run)')
-        runner.interpreter_dump_memory(sys.stderr)
+        if verbose:
+            write_header(sys.stderr, 'Memory (post run)')
+            runner.interpreter_dump_memory(sys.stderr)
 
         return result
 
@@ -134,7 +152,7 @@ def _write_memory_stored_value(
     try:
         adr2 = ALLOCATE_MEMORY_STORED_ROUTER((runner, val), val_typ)
         runner.interpreter_write_memory(adr, compiler.module_data_u32(adr2))
-        return 4
+        return TYPE_INFO_CONSTRUCTED.alloc_size
     except NoRouteForTypeException:
         to_write = WRITE_LOOKUP_MAP[val_typ.name](val)
         runner.interpreter_write_memory(adr, to_write)
@@ -286,43 +304,36 @@ def _load_memory_stored_returned_value(
     return LOAD_FROM_ADDRESS_ROUTER((runner, wasm_value), ret_type3)
 
 def _unpack(runner: runners.RunnerBase, typ: type3types.Type3, inp: bytes) -> Any:
+    typ_info = TYPE_INFO_MAP.get(typ.name, TYPE_INFO_CONSTRUCTED)
+
+    assert len(inp) == typ_info.alloc_size
+
     if typ is prelude.u8:
-        # See compiler.py, LOAD_STORE_TYPE_MAP and module_data_u8
-        assert len(inp) == 4
-        return struct.unpack('<I', inp)[0]
+        return struct.unpack('<B', inp)[0]
 
     if typ is prelude.u32:
-        assert len(inp) == 4
         return struct.unpack('<I', inp)[0]
 
     if typ is prelude.u64:
-        assert len(inp) == 8
         return struct.unpack('<Q', inp)[0]
 
     if typ is prelude.i8:
-        # See compiler.py, LOAD_STORE_TYPE_MAP and module_data_i8
-        assert len(inp) == 4
-        return struct.unpack('<i', inp)[0]
+        return struct.unpack('<b', inp)[0]
 
     if typ is prelude.i32:
-        assert len(inp) == 4
         return struct.unpack('<i', inp)[0]
 
     if typ is prelude.i64:
-        assert len(inp) == 8
         return struct.unpack('<q', inp)[0]
 
     if typ is prelude.f32:
-        assert len(inp) == 4
         return struct.unpack('<f', inp)[0]
 
     if typ is prelude.f64:
-        assert len(inp) == 8
         return struct.unpack('<d', inp)[0]
 
-    if (prelude.InternalPassAsPointer, (typ, )) in prelude.PRELUDE_TYPE_CLASS_INSTANCES_EXISTING:
+    if typ_info is TYPE_INFO_CONSTRUCTED:
         # Note: For applied types, inp should contain a 4 byte pointer
-        assert len(inp) == 4
         adr = struct.unpack('<I', inp)[0]
 
         return LOAD_FROM_ADDRESS_ROUTER((runner, adr), typ)

tests/integration/runners.py

@@ -32,12 +32,12 @@ class RunnerBase:
         """
         _dump_code(textio, self.phasm_code)
 
-    def parse(self) -> None:
+    def parse(self, verbose: bool = True) -> None:
         """
         Parses the Phasm code into an AST
         """
         self.phasm_ast = phasm_parse(self.phasm_code)
-        phasm_type3(self.phasm_ast, verbose=True)
+        phasm_type3(self.phasm_ast, verbose=verbose)
 
     def compile_ast(self) -> None:
         """
@@ -120,6 +120,8 @@ class RunnerWasmtime(RunnerBase):
 
             if vartype is int:
                 params.append(wasmtime.ValType.i32())
+            elif vartype is float:
+                params.append(wasmtime.ValType.f32())
             else:
                 raise NotImplementedError
 
@@ -128,6 +130,8 @@ class RunnerWasmtime(RunnerBase):
             pass # No return value
         elif func.__annotations__['return'] is int:
             results.append(wasmtime.ValType.i32())
+        elif func.__annotations__['return'] is float:
+            results.append(wasmtime.ValType.f32())
         else:
             raise NotImplementedError('Return type', func.__annotations__['return'])
 

tests/integration/test_lang/test_builtins.py

@@ -1,61 +0,0 @@
-import pytest
-
-from ..helpers import Suite
-
-
-@pytest.mark.integration_test
-def test_foldl_1():
-    code_py = """
-def u8_or(l: u8, r: u8) -> u8:
-    return l | r
-
-@exported
-def testEntry(b: bytes) -> u8:
-    return foldl(u8_or, 128, b)
-"""
-    suite = Suite(code_py)
-
-    result = suite.run_code(b'')
-    assert 128 == result.returned_value
-
-    result = suite.run_code(b'\x80')
-    assert 128 == result.returned_value
-
-    result = suite.run_code(b'\x80\x40')
-    assert 192 == result.returned_value
-
-    result = suite.run_code(b'\x80\x40\x20\x10')
-    assert 240 == result.returned_value
-
-    result = suite.run_code(b'\x80\x40\x20\x10\x08\x04\x02\x01')
-    assert 255 == result.returned_value
-
-@pytest.mark.integration_test
-def test_foldl_2():
-    code_py = """
-def xor(l: u8, r: u8) -> u8:
-    return l ^ r
-
-@exported
-def testEntry(a: bytes, b: bytes) -> u8:
-    return foldl(xor, 0, a) ^ foldl(xor, 0, b)
-"""
-    suite = Suite(code_py)
-
-    result = suite.run_code(b'\x55\x0F', b'\x33\x80')
-    assert 233 == result.returned_value
-
-@pytest.mark.integration_test
-def test_foldl_3():
-    code_py = """
-def xor(l: u32, r: u8) -> u32:
-    return l ^ extend(r)
-
-@exported
-def testEntry(a: bytes) -> u32:
-    return foldl(xor, 0, a)
-"""
-    suite = Suite(code_py)
-
-    result = suite.run_code(b'\x55\x0F\x33\x80')
-    assert 233 == result.returned_value

tests/integration/test_lang/test_subscriptable.py

@@ -23,6 +23,23 @@ def testEntry(f: {type_}) -> u8:
 
     assert exp_result == result.returned_value
 
+@pytest.mark.integration_test
+@pytest.mark.parametrize('type_, in_put, exp_result', [
+    ('(u8, u8, u8, )', (45, 46, 47), 46, ),
+    ('u8[5]', (45, 46, 47, 48, 49), 46, ),
+    ('bytes', b'This is a test', 104)
+])
+def test_subscript_1(type_, in_put, exp_result):
+    code_py = f"""
+@exported
+def testEntry(f: {type_}) -> u8:
+    return f[1]
+"""
+
+    result = Suite(code_py).run_code(in_put)
+
+    assert exp_result == result.returned_value
+
 @pytest.mark.integration_test
 @pytest.mark.parametrize('type_, in_put, exp_result', [
     ('(u8, u8, u8, )', (45, 46, 47), 47, ),
@@ -82,7 +99,7 @@ def testEntry(x: (u8, u32, u64)) -> u64:
 @pytest.mark.parametrize('type_, in_put', [
     ('(u8, u8, )', (45, 46), ),
     ('u8[2]', (45, 46), ),
-    # bytes isn't known at runtime so works like normal
+    # dynamic_array isn't known at runtime so works like normal
 ])
 def test_subscript_oob_constant_low(type_, in_put):
     code_py = f"""

tests/integration/test_typeclasses/test_foldable.py

@@ -36,6 +36,142 @@ def testEntry(x: Foo[4]) -> Foo:
     with pytest.raises(Type3Exception, match='Missing type class instantation: NatNum Foo'):
         Suite(code_py).run_code()
 
+@pytest.mark.integration_test
+@pytest.mark.parametrize('length', [1, 5, 13])
+@pytest.mark.parametrize('direction', ['foldl', 'foldr'])
+def test_foldable_foldl_foldr_size(direction, length):
+    code_py = f"""
+def u64_add(l: u64, r: u64) -> u64:
+    return l + r
+
+@exported
+def testEntry(b: u64[{length}]) -> u64:
+    return {direction}(u64_add, 100, b)
+"""
+    suite = Suite(code_py)
+
+    in_put = tuple(range(1, length + 1))
+
+    result = suite.run_code(in_put)
+    assert (100 + sum(in_put)) == result.returned_value
+
+@pytest.mark.integration_test
+@pytest.mark.parametrize('direction', ['foldl', 'foldr'])
+def test_foldable_foldl_foldr_compounded_type(direction):
+    code_py = f"""
+def combine_foldl(b: u64, a: (u32, u32, )) -> u64:
+    return extend(a[0] * a[1]) + b
+
+def combine_foldr(a: (u32, u32, ), b: u64) -> u64:
+    return extend(a[0] * a[1]) + b
+
+@exported
+def testEntry(b: (u32, u32, )[3]) -> u64:
+    return {direction}(combine_{direction}, 10000, b)
+"""
+    suite = Suite(code_py)
+
+    result = suite.run_code(((2, 5), (25, 4), (125, 8)))
+    assert 11110 == result.returned_value
+
+@pytest.mark.integration_test
+@pytest.mark.parametrize('in_put, direction, exp_result', [
+    ([], 'foldl', 0, ),
+    ([], 'foldr', 0, ),
+
+    ([1], 'foldl', -1, ),
+    ([1], 'foldr', 1, ),
+
+    ([1,2], 'foldl', -3, ),
+    ([1,2], 'foldr', -1, ),
+
+    ([1,2,3], 'foldl', -6, ),
+    ([1,2,3], 'foldr', 2, ),
+
+    ([1,2,3,4], 'foldl', -10, ),
+    ([1,2,3,4], 'foldr', -2, ),
+
+    ([1,2,3,4,5], 'foldl', -15, ),
+    ([1,2,3,4,5], 'foldr', 3, ),
+
+    ([1,2,3,4,5,6], 'foldl', -21, ),
+    ([1,2,3,4,5,6], 'foldr', -3, ),
+
+    ([1,2,3,4,5,6,7], 'foldl', -28, ),
+    ([1,2,3,4,5,6,7], 'foldr', 4, ),
+
+    ([1,2,3,4,5,6,7,8], 'foldl', -36, ),
+    ([1,2,3,4,5,6,7,8], 'foldr', -4, ),
+])
+def test_foldable_foldl_foldr_result(direction, in_put, exp_result):
+    # See https://stackoverflow.com/a/13280185
+    code_py = f"""
+def i32_sub(l: i32, r: i32) -> i32:
+    return l - r
+
+@exported
+def testEntry(b: i32[{len(in_put)}]) -> i32:
+    return {direction}(i32_sub, 0, b)
+"""
+    suite = Suite(code_py)
+
+    result = suite.run_code(tuple(in_put))
+    assert exp_result == result.returned_value
+
+@pytest.mark.integration_test
+def test_foldable_foldl_bytes():
+    code_py = """
+def u8_or(l: u8, r: u8) -> u8:
+    return l | r
+
+@exported
+def testEntry(b: bytes) -> u8:
+    return foldl(u8_or, 0, b)
+"""
+    suite = Suite(code_py)
+
+    result = suite.run_code(b'')
+    assert 0 == result.returned_value
+
+    result = suite.run_code(b'\x80')
+    assert 128 == result.returned_value
+
+    result = suite.run_code(b'\x80\x40')
+    assert 192 == result.returned_value
+
+    result = suite.run_code(b'\x80\x40\x20\x10')
+    assert 240 == result.returned_value
+
+    result = suite.run_code(b'\x80\x40\x20\x10\x08\x04\x02\x01')
+    assert 255 == result.returned_value
+
+@pytest.mark.integration_test
+@pytest.mark.parametrize('in_typ', ['i8', 'i8[3]'])
+def test_foldable_argument_must_be_a_function(in_typ):
+    code_py = f"""
+@exported
+def testEntry(x: {in_typ}, y: i32, z: i64[3]) -> i32:
+    return foldl(x, y, z)
+"""
+
+    r_in_typ = in_typ.replace('[', '\\[').replace(']', '\\]')
+
+    with pytest.raises(Type3Exception, match=f'{r_in_typ} must be a function instead'):
+        Suite(code_py).run_code()
+
+@pytest.mark.integration_test
+def test_foldable_argument_must_be_right_function():
+    code_py = """
+def foo(l: i32, r: i64) -> i64:
+    return extend(l) + r
+
+@exported
+def testEntry(i: i64, l: i64[3]) -> i64:
+    return foldr(foo, i, l)
+"""
+
+    with pytest.raises(Type3Exception, match=r'Callable\[i64, i64, i64\] must be Callable\[i32, i64, i64\] instead'):
+        Suite(code_py).run_code()
 
 @pytest.mark.integration_test
 def test_foldable_invalid_return_type():