From 9fb58067645da1aa02dcfa995cb61fb86a2dff16 Mon Sep 17 00:00:00 2001
From: protolambda <proto@protolambda.com>
Date: Tue, 25 Jun 2019 00:24:13 +0200
Subject: [PATCH] be explicit about input for balance sum

---
 scripts/build_spec.py             | 4 ++--
 specs/core/0_beacon-chain.md      | 6 +++---
 specs/core/1_shard-data-chains.md | 4 ++--
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/scripts/build_spec.py b/scripts/build_spec.py
index 08793869f..237c24384 100644
--- a/scripts/build_spec.py
+++ b/scripts/build_spec.py
@@ -12,7 +12,7 @@ from typing import (
 
 
 PHASE0_IMPORTS = '''from typing import (
-    Any, Callable, Iterable, Dict, Set, Sequence, Tuple,
+    Any, Callable, Dict, Set, Sequence, Tuple,
 )
 
 from dataclasses import (
@@ -37,7 +37,7 @@ from eth2spec.utils.bls import (
 from eth2spec.utils.hash_function import hash
 '''
 PHASE1_IMPORTS = '''from typing import (
-    Any, Callable, Dict, Iterable, Optional, Set, Sequence, Tuple,
+    Any, Callable, Dict, Optional, Set, Sequence, Tuple,
     List as TypingList
 )
 
diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index 4d6be89f7..b8cab7eaf 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -908,7 +908,7 @@ def bytes_to_int(data: bytes) -> int:
 ### `get_total_balance`
 
 ```python
-def get_total_balance(state: BeaconState, indices: Iterable[ValidatorIndex]) -> Gwei:
+def get_total_balance(state: BeaconState, indices: Set[ValidatorIndex]) -> Gwei:
     """
     Return the combined effective balance of the ``indices``. (1 Gwei minimum to avoid divisions by zero.)
     """
@@ -1383,7 +1383,7 @@ def process_crosslinks(state: BeaconState) -> None:
     for epoch in (get_previous_epoch(state), get_current_epoch(state)):
         for offset in range(get_epoch_committee_count(state, epoch)):
             shard = Shard((get_epoch_start_shard(state, epoch) + offset) % SHARD_COUNT)
-            crosslink_committee = get_crosslink_committee(state, epoch, shard)
+            crosslink_committee = set(get_crosslink_committee(state, epoch, shard))
             winning_crosslink, attesting_indices = get_winning_crosslink_and_attesting_indices(state, epoch, shard)
             if 3 * get_total_balance(state, attesting_indices) >= 2 * get_total_balance(state, crosslink_committee):
                 state.current_crosslinks[shard] = winning_crosslink
@@ -1456,7 +1456,7 @@ def get_crosslink_deltas(state: BeaconState) -> Tuple[Sequence[Gwei], Sequence[G
     epoch = get_previous_epoch(state)
     for offset in range(get_epoch_committee_count(state, epoch)):
         shard = Shard((get_epoch_start_shard(state, epoch) + offset) % SHARD_COUNT)
-        crosslink_committee = get_crosslink_committee(state, epoch, shard)
+        crosslink_committee = set(get_crosslink_committee(state, epoch, shard))
         winning_crosslink, attesting_indices = get_winning_crosslink_and_attesting_indices(state, epoch, shard)
         attesting_balance = get_total_balance(state, attesting_indices)
         committee_balance = get_total_balance(state, crosslink_committee)
diff --git a/specs/core/1_shard-data-chains.md b/specs/core/1_shard-data-chains.md
index f84b0dd46..dd48a842a 100644
--- a/specs/core/1_shard-data-chains.md
+++ b/specs/core/1_shard-data-chains.md
@@ -378,7 +378,7 @@ Let:
 * `shard` be a valid `Shard`
 * `shard_blocks` be the `ShardBlock` list such that `shard_blocks[slot]` is the canonical `ShardBlock` for shard `shard` at slot `slot`
 * `beacon_state` be the canonical `BeaconState`
-* `valid_attestations` be the list of valid `Attestation`, recursively defined
+* `valid_attestations` be the set of valid `Attestation` objects, recursively defined
 * `candidate` be a candidate `Attestation` which is valid under Phase 0 rules, and for which validity is to be determined under Phase 1 rules by running `is_valid_beacon_attestation`
 
 ```python
@@ -388,7 +388,7 @@ def is_valid_beacon_attestation(shard: Shard,
                                 valid_attestations: Set[Attestation],
                                 candidate: Attestation) -> bool:
     # Check if attestation is already determined valid
-    for _, attestation in enumerate(valid_attestations):
+    for attestation in valid_attestations:
         if candidate == attestation:
             return True