Move active_validators into own crate

Cargo.toml

@@ -34,6 +34,7 @@ name = "lighthouse"
 members = [
 	"beacon_chain/chain",
 	"beacon_chain/types",
+	"beacon_chain/utils/active-validators",
 	"beacon_chain/utils/bls",
 	"beacon_chain/utils/boolean-bitfield",
 	"beacon_chain/utils/hashing",

beacon_chain/utils/active-validators/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "active-validators"
+version = "0.1.0"
+authors = ["Paul Hauner <paul@paulhauner.com>"]
+
+[dependencies]
+types = { path = "../../types" }

beacon_chain/utils/active-validators/src/lib.rs

@@ -1,8 +1,14 @@
+extern crate types;
+
 use types::{
     ValidatorRecord,
     ValidatorStatus,
 };
 
+pub fn validator_is_active(v: &ValidatorRecord) -> bool {
+    v.status == ValidatorStatus::Active as u8
+}
+
 /// Returns the indicies of each active validator in a given vec of validators.
 pub fn active_validator_indices(validators: &[ValidatorRecord])
     -> Vec<usize>
@@ -10,9 +16,10 @@ pub fn active_validator_indices(validators: &[ValidatorRecord])
     validators.iter()
         .enumerate()
         .filter_map(|(i, validator)| {
-            match validator.status {
-                x if x == ValidatorStatus::Active as u8 => Some(i),
-                _ => None
+            if validator_is_active(&validator) {
+                Some(i)
+            } else {
+                None
             }
         })
         .collect()

beacon_chain/validator_shuffling/Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 authors = ["Paul Hauner <paul@paulhauner.com>"]
 
 [dependencies]
+active-validators = { path = "../utils/active-validators" }
 honey-badger-split = { path = "../utils/honey-badger-split" }
 types = { path = "../types" }
 vec_shuffle = { path = "../utils/vec_shuffle" }

beacon_chain/validator_shuffling/src/lib.rs

@@ -1,8 +1,8 @@
+extern crate active_validators;
 extern crate honey_badger_split;
 extern crate vec_shuffle;
 extern crate types;
 
-mod active_validator_indices;
 mod shuffle;
 
 pub use shuffle::{

beacon_chain/validator_shuffling/src/shuffle.rs

@@ -1,5 +1,6 @@
 use std::cmp::min;
 
+use active_validators::active_validator_indices;
 use honey_badger_split::SplitExt;
 use vec_shuffle::{
     shuffle,
@@ -11,7 +12,6 @@ use types::{
     ChainConfig,
 };
 
-use super::active_validator_indices::active_validator_indices;
 
 type DelegatedCycle = Vec<Vec<ShardAndCommittee>>;