Remove the RPC helpers module (#3967)

substrate/core/rpc/src/helpers.rs

-// Copyright 2018-2019 Parity Technologies (UK) Ltd.
-// This file is part of Substrate.
-
-// Substrate is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-
-// Substrate is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-
-// You should have received a copy of the GNU General Public License
-// along with Substrate.  If not, see <http://www.gnu.org/licenses/>.
-
-/// Unwraps the trailing parameter or falls back with the closure result.
-pub fn unwrap_or_else<F, H, E>(or_else: F, optional: Option<H>) -> Result<H, E> where
-	F: FnOnce() -> Result<H, E>,
-{
-	match optional.into() {
-		None => or_else(),
-		Some(x) => Ok(x),
-	}
-}

substrate/core/rpc/src/lib.rs

@@ -20,7 +20,6 @@
 
 #![warn(missing_docs)]
 
-mod helpers;
 mod metadata;
 
 pub use api::Subscriptions;

substrate/core/rpc/src/state/state_full.rs

@@ -77,7 +77,7 @@ impl<B, E, Block: BlockT, RA> FullState<B, E, Block, RA>
 
 	/// Returns given block hash or best block hash if None is passed.
 	fn block_or_best(&self, hash: Option<Block::Hash>) -> ClientResult<Block::Hash> {
-		crate::helpers::unwrap_or_else(|| Ok(self.client.info().chain.best_hash), hash)
+		Ok(hash.unwrap_or_else(|| self.client.info().chain.best_hash))
 	}
 
 	/// Splits the `query_storage` block range into 'filtered' and 'unfiltered' subranges.