perf: optimize callback

Author: slikts

src/DeepCompositeSymbol.ts

@@ -4,7 +4,7 @@ import { isObject } from './helpers';
 // tslint:disable-next-line: variable-name
 const DeepCompositeSymbol: typeof Tuple.symbol = ((object: any) => {
   const entries = Object.entries(object);
-  // Recursively replace non-tuple object values with
+  // Recursively replace non-tuple object values with tuples
   entries.forEach(update);
   return Tuple.unsafeSymbol(...Array.prototype.concat.apply([], entries));
 }) as any;

src/Tuple.ts

@@ -125,15 +125,15 @@ export default class Tuple<A> extends (Array as any) implements ArrayLike<A>, It
   }
 
   static unsafeSymbol(...values: any[]): any {
-    return getDefaultLazy(symbolKey, () => Symbol(), getUnsafeLeaf(values));
+    return getDefaultLazy(symbolKey, Symbol, getUnsafeLeaf(values));
   }
 
   [Symbol.iterator](): IterableIterator<A> {
     return arraylikeToIterable(this);
   }
 }
 
-// Cache keys for each tuple type
+// Root cache keys for each tuple type
 const tupleKey = Symbol();
 const symbolKey = Symbol();