Infer types where possible, e.g. uint64+uint64=uint64

specs/phase0/beacon-chain.md

@@ -561,9 +561,9 @@ def integer_squareroot(n: uint64) -> uint64:
     x = n
     y = (x + 1) // 2
     while y < x:
-        x = uint64(y)
+        x = y
         y = (x + n // x) // 2
-    return uint64(x)
+    return x
 ```
 
 #### `xor`
@@ -732,15 +732,11 @@ def compute_shuffled_index(index: uint64, index_count: uint64, seed: Bytes32) ->
 
     # Swap or not (https://link.springer.com/content/pdf/10.1007%2F978-3-642-32009-5_1.pdf)
     # See the 'generalized domain' algorithm on page 3
-    for current_round in map(uint64, range(SHUFFLE_ROUND_COUNT)):
+    for current_round in range(SHUFFLE_ROUND_COUNT):
         pivot = bytes_to_int(hash(seed + int_to_bytes(current_round, length=1))[0:8]) % index_count
-        flip = uint64((pivot + index_count - index) % index_count)
+        flip = (pivot + index_count - index) % index_count
         position = max(index, flip)
-        source = hash(
-            seed
-            + int_to_bytes(current_round, length=1)
-            + int_to_bytes(uint64(position // 256), length=4)
-        )
+        source = hash(seed + int_to_bytes(current_round, length=1) + int_to_bytes(position // 256, length=4))
         byte = source[(position % 256) // 8]
         bit = (byte >> (position % 8)) % 2
         index = flip if bit else index
@@ -757,10 +753,11 @@ def compute_proposer_index(state: BeaconState, indices: Sequence[ValidatorIndex]
     """
     assert len(indices) > 0
     MAX_RANDOM_BYTE = 2**8 - 1
-    i = 0
+    i = uint64(0)
+    total = uint64(len(indices))
     while True:
-        candidate_index = indices[compute_shuffled_index(uint64(i % len(indices)), uint64(len(indices)), seed)]
-        random_byte = hash(seed + int_to_bytes(uint64(i // 32), length=8))[i % 32]
+        candidate_index = indices[compute_shuffled_index(i % total, total, seed)]
+        random_byte = hash(seed + int_to_bytes(i // 32, length=8))[i % 32]
         effective_balance = state.validators[candidate_index].effective_balance
         if effective_balance * MAX_RANDOM_BYTE >= MAX_EFFECTIVE_BALANCE * random_byte:
             return candidate_index
@@ -938,7 +935,7 @@ def get_validator_churn_limit(state: BeaconState) -> uint64:
     Return the validator churn limit for the current epoch.
     """
     active_validator_indices = get_active_validator_indices(state, get_current_epoch(state))
-    return max(MIN_PER_EPOCH_CHURN_LIMIT, uint64(len(active_validator_indices) // CHURN_LIMIT_QUOTIENT))
+    return max(MIN_PER_EPOCH_CHURN_LIMIT, uint64(len(active_validator_indices)) // CHURN_LIMIT_QUOTIENT)
 ```
 
 #### `get_seed`
@@ -961,7 +958,7 @@ def get_committee_count_per_slot(state: BeaconState, epoch: Epoch) -> uint64:
     """
     return max(uint64(1), min(
         MAX_COMMITTEES_PER_SLOT,
-        uint64(len(get_active_validator_indices(state, epoch)) // SLOTS_PER_EPOCH // TARGET_COMMITTEE_SIZE),
+        uint64(len(get_active_validator_indices(state, epoch))) // SLOTS_PER_EPOCH // TARGET_COMMITTEE_SIZE,
     ))
 ```
 
@@ -977,8 +974,8 @@ def get_beacon_committee(state: BeaconState, slot: Slot, index: CommitteeIndex)
     return compute_committee(
         indices=get_active_validator_indices(state, epoch),
         seed=get_seed(state, epoch, DOMAIN_BEACON_ATTESTER),
-        index=uint64((slot % SLOTS_PER_EPOCH) * committees_per_slot + index),
-        count=uint64(committees_per_slot * SLOTS_PER_EPOCH),
+        index=(slot % SLOTS_PER_EPOCH) * committees_per_slot + index,
+        count=committees_per_slot * SLOTS_PER_EPOCH,
     )
 ```
 
@@ -1501,12 +1498,12 @@ def get_attestation_deltas(state: BeaconState) -> Tuple[Sequence[Gwei], Sequence
     _, inactivity_penalties = get_inactivity_penalty_deltas(state)
 
     rewards = [
-        Gwei(source_rewards[i] + target_rewards[i] + head_rewards[i] + inclusion_delay_rewards[i])
+        source_rewards[i] + target_rewards[i] + head_rewards[i] + inclusion_delay_rewards[i]
         for i in range(len(state.validators))
     ]
 
     penalties = [
-        Gwei(source_penalties[i] + target_penalties[i] + head_penalties[i] + inactivity_penalties[i])
+        source_penalties[i] + target_penalties[i] + head_penalties[i] + inactivity_penalties[i]
         for i in range(len(state.validators))
     ]
 
@@ -1773,13 +1770,13 @@ def process_deposit(state: BeaconState, deposit: Deposit) -> None:
     assert is_valid_merkle_branch(
         leaf=hash_tree_root(deposit.data),
         branch=deposit.proof,
-        depth=uint64(DEPOSIT_CONTRACT_TREE_DEPTH + 1),  # Add 1 for the List length mix-in
+        depth=DEPOSIT_CONTRACT_TREE_DEPTH + 1,  # Add 1 for the List length mix-in
         index=state.eth1_deposit_index,
         root=state.eth1_data.deposit_root,
     )
 
     # Deposits must be processed in order
-    state.eth1_deposit_index = uint64(state.eth1_deposit_index + 1)
+    state.eth1_deposit_index += 1
 
     pubkey = deposit.data.pubkey
     amount = deposit.data.amount