Removed the len special casing

TODO.md

@@ -23,9 +23,6 @@
   - At first glance, looks like failure in the typing system
   - Related to the FIXME in phasm_type3?
   - Related: Parser is putting stuff in ModuleDataBlock
-- WEBASSEMBLY_BUILTIN_BYTES_OPS is special cased
-  - Should be part of a prelude (?)
-  - In Haskell this is not a type class
 - Casting is not implemented except u32 which is special cased
 - Make prelude more an actual thing
   - Merge in type3types.LOOKUP_TABLE

phasm/codestyle.py

@@ -76,10 +76,6 @@ def expression(inp: ourlang.Expression) -> str:
         return str(inp.variable.name)
 
     if isinstance(inp, ourlang.UnaryOp):
-        if (
-            inp.operator in ourlang.WEBASSEMBLY_BUILTIN_BYTES_OPS):
-            return f'{inp.operator}({expression(inp.right)})'
-
         if inp.operator == 'cast':
             mtyp = type3(inp.type3)
             if mtyp is None:

phasm/compiler.py

@@ -233,6 +233,9 @@ INSTANCES = {
         'a=f32': stdlib_types.f32_natnum_arithmic_shift_right,
         'a=f64': stdlib_types.f64_natnum_arithmic_shift_right,
     },
+    prelude.Sized_.methods['len']: {
+        'a=bytes': stdlib_types.bytes_sized_len,
+    },
 }
 
 def phasm_compile(inp: ourlang.Module) -> wasm.Module:
@@ -458,12 +461,6 @@ def expression(wgn: WasmGenerator, inp: ourlang.Expression) -> None:
 
         assert isinstance(inp.type3, type3types.Type3), type3placeholders.TYPE3_ASSERTION_ERROR
 
-        if inp.type3 == prelude.u32:
-            if inp.operator == 'len':
-                if inp.right.type3 == prelude.bytes_:
-                    wgn.i32.load()
-                    return
-
         if inp.operator == 'cast':
             if inp.type3 == prelude.u32 and inp.right.type3 == prelude.u8:
                 # Nothing to do, you can use an u8 value as a u32 no problem

phasm/ourlang.py

@@ -4,14 +4,11 @@ Contains the syntax tree for ourlang
 import enum
 from typing import Dict, Iterable, List, Optional, Union
 
-from typing_extensions import Final
-
 from . import prelude
 from .type3.placeholders import PlaceholderForType, Type3OrPlaceholder
 from .type3.typeclasses import Type3ClassMethod
 from .type3.types import Type3
 
-WEBASSEMBLY_BUILTIN_BYTES_OPS: Final = ('len', )
 
 class Expression:
     """

phasm/parser.py

@@ -490,14 +490,6 @@ class OurVisitor:
             )
             unary_op.type3 = prelude.u32
             return unary_op
-        elif node.func.id == 'len':
-            if 1 != len(node.args):
-                _raise_static_error(node, f'Function {node.func.id} requires 1 arguments but {len(node.args)} are given')
-
-            return UnaryOp(
-                'len',
-                self.visit_Module_FunctionDef_expr(module, function, our_locals, node.args[0]),
-            )
         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')

phasm/prelude/__init__.py

@@ -241,6 +241,12 @@ Floating = Type3Class('Floating', [a], methods={
 instance_type_class(Floating, f32)
 instance_type_class(Floating, f64)
 
+Sized_ = Type3Class('Sized', [a], methods={
+    'len': [a, u32],
+}, operators={})  # FIXME: Once we get type class families, add [] here
+
+instance_type_class(Sized_, bytes_)
+
 PRELUDE_TYPE_CLASSES = {
     'Eq': Eq,
     'Ord': Ord,
@@ -271,4 +277,5 @@ PRELUDE_METHODS = {
     **Integral.methods,
     **IntNum.methods,
     **NatNum.methods,
+    **Sized_.methods,
 }

phasm/stdlib/types.py

@@ -858,3 +858,10 @@ def f32_intnum_neg(g: Generator) -> None:
 
 def f64_intnum_neg(g: Generator) -> None:
     g.f64.neg()
+
+## ###
+## Class Sized
+
+def bytes_sized_len(g: Generator) -> None:
+    # The length is stored in the first 4 bytes
+    g.i32.load()

phasm/type3/constraints.py

@@ -245,7 +245,7 @@ class MustImplementTypeClassConstraint(ConstraintBase):
     type3: placeholders.Type3OrPlaceholder
 
     DATA = {
-        'bytes': {'Foldable', 'Sized'},
+        'bytes': {'Foldable'},
     }
 
     def __init__(self, type_class3: Union[str, typeclasses.Type3Class], type3: placeholders.Type3OrPlaceholder, comment: Optional[str] = None) -> None:

phasm/type3/constraintsgenerator.py

@@ -48,12 +48,6 @@ def expression(ctx: Context, inp: ourlang.Expression) -> ConstraintGenerator:
         return
 
     if isinstance(inp, ourlang.UnaryOp):
-        if 'len' == inp.operator:
-            yield from expression(ctx, inp.right)
-            yield MustImplementTypeClassConstraint('Sized', inp.right.type3)
-            yield SameTypeConstraint(prelude.u32, inp.type3, comment='len :: Sized a => a -> u32')
-            return
-
         if 'cast' == inp.operator:
             yield from expression(ctx, inp.right)
             yield CastableConstraint(inp.right.type3, inp.type3)

tests/integration/test_lang/test_bytes.py

@@ -1,16 +0,0 @@
-import pytest
-
-from ..helpers import Suite
-
-
-@pytest.mark.integration_test
-def test_bytes_length():
-    code_py = """
-@exported
-def testEntry(f: bytes) -> u32:
-    return len(f)
-"""
-
-    result = Suite(code_py).run_code(b'This yet is another test')
-
-    assert 24 == result.returned_value

tests/integration/test_lang/test_sized.py

@@ -0,0 +1,20 @@
+import pytest
+
+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
+])
+def test_len(type_, in_put, exp_result):
+    code_py = f"""
+@exported
+def testEntry(f: {type_}) -> u32:
+    return len(f)
+"""
+
+    result = Suite(code_py).run_code(in_put)
+
+    assert exp_result == result.returned_value