From a4969ca4981ead19c6185ccb7e07cf533532e112 Mon Sep 17 00:00:00 2001
From: Niklas Adolfsson <niklasadolfsson1@gmail.com>
Date: Sun, 8 Sep 2019 14:30:54 +0200
Subject: [PATCH] fix: remove needless use of itertools (#11029)

* Remove needless use of `itertools` in `ethcore-light`
* Replace `itertools::repeat::call` with `std::iter::repeat_with`
---
 Cargo.lock                                 | 1 -
 ethcore/engines/authority-round/src/lib.rs | 4 ++--
 ethcore/light/Cargo.toml                   | 1 -
 ethcore/light/src/client/header_chain.rs   | 2 +-
 ethcore/light/src/lib.rs                   | 2 --
 5 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 63166c5c5..2c0cf4897 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1182,7 +1182,6 @@ dependencies = [
  "fastmap 0.1.0",
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "hash-db 0.15.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "itertools 0.5.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "journaldb 0.2.0",
  "keccak-hash 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "keccak-hasher 0.1.1",
diff --git a/ethcore/engines/authority-round/src/lib.rs b/ethcore/engines/authority-round/src/lib.rs
index 98aa8c22a..202b4dbc6 100644
--- a/ethcore/engines/authority-round/src/lib.rs
+++ b/ethcore/engines/authority-round/src/lib.rs
@@ -1506,7 +1506,7 @@ impl Engine for AuthorityRound {
 
 		let mut hash = *chain_head.parent_hash();
 
-		let mut ancestry = itertools::repeat_call(move || {
+		let mut ancestry = std::iter::repeat_with(move || {
 			chain(hash).and_then(|header| {
 				if header.number() == 0 { return None }
 				hash = *header.parent_hash();
@@ -1548,7 +1548,7 @@ impl Engine for AuthorityRound {
 				// to construct transition proof. author == ec_recover(sig) known
 				// since the blocks are in the DB.
 				let mut hash = chain_head.hash();
-				let mut finality_proof: Vec<_> = itertools::repeat_call(move || {
+				let mut finality_proof: Vec<_> = std::iter::repeat_with(move || {
 					chain(hash).and_then(|header| {
 						hash = *header.parent_hash();
 						if header.number() == 0 { None }
diff --git a/ethcore/light/Cargo.toml b/ethcore/light/Cargo.toml
index 32e0c5e00..6309298d1 100644
--- a/ethcore/light/Cargo.toml
+++ b/ethcore/light/Cargo.toml
@@ -34,7 +34,6 @@ rlp_derive = { path = "../../util/rlp-derive" }
 smallvec = "0.6"
 futures = "0.1"
 rand = "0.6"
-itertools = "0.5"
 bincode = "1.1"
 serde = "1.0"
 serde_derive = "1.0"
diff --git a/ethcore/light/src/client/header_chain.rs b/ethcore/light/src/client/header_chain.rs
index 22b83c732..d473df97a 100644
--- a/ethcore/light/src/client/header_chain.rs
+++ b/ethcore/light/src/client/header_chain.rs
@@ -550,7 +550,7 @@ impl HeaderChain {
 						let canon = &era_entry.candidates[0];
 						(canon.hash, canon.total_difficulty)
 					};
-					cht::compute_root(cht_num, ::itertools::repeat_call(iter))
+					cht::compute_root(cht_num, std::iter::repeat_with(iter))
 						.expect("fails only when too few items; this is checked; qed")
 				};
 
diff --git a/ethcore/light/src/lib.rs b/ethcore/light/src/lib.rs
index 61ce17e56..0f748e920 100644
--- a/ethcore/light/src/lib.rs
+++ b/ethcore/light/src/lib.rs
@@ -67,11 +67,9 @@ extern crate ethereum_types;
 extern crate ethcore_miner as miner;
 extern crate hash_db;
 extern crate parity_util_mem;
-extern crate parity_util_mem as mem;
 extern crate parity_util_mem as malloc_size_of;
 extern crate failsafe;
 extern crate futures;
-extern crate itertools;
 extern crate keccak_hasher;
 extern crate machine;
 extern crate memory_db;