primitives: single zero hash declaration (leanEthereum#189)

Author: tcoratger

src/lean_spec/subspecs/containers/state/state.py

@@ -6,9 +6,9 @@
 justified and finalized.
 """
 
-from lean_spec.subspecs.ssz.constants import ZERO_HASH
 from lean_spec.subspecs.ssz.hash import hash_tree_root
 from lean_spec.types import (
+    ZERO_HASH,
     Boolean,
     Bytes32,
     Container,

src/lean_spec/subspecs/forkchoice/constants.py

@@ -10,9 +10,7 @@
     Block,
     SignedAttestation,
 )
-from lean_spec.types import Bytes32, ValidatorIndex
-
-from .constants import ZERO_HASH
+from lean_spec.types import ZERO_HASH, Bytes32, ValidatorIndex
 
 
 def get_fork_choice_head(

src/lean_spec/subspecs/forkchoice/helpers.py

@@ -1,6 +1,7 @@
 """SSZ (Simple Serialize) implementation."""
 
-from .constants import ZERO_HASH
+from lean_spec.types import ZERO_HASH
+
 from .hash import HashTreeRoot, hash_tree_root
 
 __all__ = [

src/lean_spec/subspecs/ssz/__init__.py

@@ -1,12 +1,7 @@
 """Constants defined in the SSZ specification."""
 
-from lean_spec.types.byte_arrays import Bytes32
-
 BYTES_PER_CHUNK: int = 32
 """Number of bytes per Merkle chunk."""
 
 BITS_PER_BYTE: int = 8
 """Number of bits per byte."""
-
-ZERO_HASH: Bytes32 = Bytes32(b"\x00" * BYTES_PER_CHUNK)
-"""A zero hash, used for padding in Merkleization."""

src/lean_spec/subspecs/ssz/constants.py

@@ -6,10 +6,9 @@
 
 from pydantic import Field, model_validator
 
-from lean_spec.types import StrictBaseModel
+from lean_spec.types import ZERO_HASH, StrictBaseModel
 from lean_spec.types.byte_arrays import Bytes32
 
-from ..constants import ZERO_HASH
 from ..utils import hash_nodes
 from .gindex import GeneralizedIndex
 

src/lean_spec/subspecs/ssz/merkle_proof/proof.py

@@ -2,8 +2,8 @@
 
 from typing import List, Sequence
 
-from lean_spec.subspecs.ssz.constants import ZERO_HASH
 from lean_spec.subspecs.ssz.utils import get_power_of_two_ceil, hash_nodes
+from lean_spec.types import ZERO_HASH
 from lean_spec.types.byte_arrays import Bytes32
 
 

src/lean_spec/subspecs/ssz/merkle_proof/tree.py

@@ -4,8 +4,8 @@
 
 from typing import List, Optional, Sequence
 
-from lean_spec.subspecs.ssz.constants import ZERO_HASH
 from lean_spec.subspecs.ssz.utils import get_power_of_two_ceil, hash_nodes
+from lean_spec.types import ZERO_HASH
 from lean_spec.types.byte_arrays import Bytes32
 
 

src/lean_spec/subspecs/ssz/merkleization.py

@@ -3,7 +3,7 @@
 from .base import CamelModel, StrictBaseModel
 from .basispt import BasisPoint
 from .boolean import Boolean
-from .byte_arrays import Bytes32, Bytes52, Bytes3116
+from .byte_arrays import ZERO_HASH, Bytes32, Bytes52, Bytes3116
 from .collections import SSZList, SSZVector
 from .container import Container
 from .uint import Uint64
@@ -15,6 +15,7 @@
     "Bytes32",
     "Bytes52",
     "Bytes3116",
+    "ZERO_HASH",
     "CamelModel",
     "StrictBaseModel",
     "ValidatorIndex",

src/lean_spec/types/__init__.py

@@ -213,6 +213,10 @@ class Bytes32(BaseBytes):
     LENGTH = 32
 
 
+ZERO_HASH: Bytes32 = Bytes32.zero()
+"""All-zero hash (32 bytes of zeros)."""
+
+
 class Bytes48(BaseBytes):
     """Fixed-size byte array of exactly 48 bytes."""