Remove custom util implementation in favor of quiver

lib/models/documents/attribute.dart

@@ -1,4 +1,3 @@
-import 'package:flutter_quill/utils/hashcode.dart' as hashcode;
 import 'package:quiver/core.dart';
 
 enum AttributeScope {
@@ -185,7 +184,7 @@ class Attribute<T> {
   }
 
   @override
-  int get hashCode => hashcode.hash3(key, scope, value);
+  int get hashCode => hash3(key, scope, value);
 
   @override
   String toString() {

lib/models/documents/style.dart

@@ -1,6 +1,5 @@
 import 'package:collection/collection.dart';
 import 'package:flutter_quill/models/documents/attribute.dart';
-import 'package:flutter_quill/utils/hashcode.dart' as hashcode;
 import 'package:quiver/core.dart';
 
 /* Collection of style attributes */
@@ -102,8 +101,8 @@ class Style {
   @override
   int get hashCode {
     final hashes = _attributes.entries
-        .map((entry) => hashcode.hash2(entry.key, entry.value));
-    return hashcode.hashObjects(hashes);
+        .map((entry) => hash2(entry.key, entry.value));
+    return hashObjects(hashes);
   }
 
   @override

lib/models/quill_delta.dart

@@ -7,7 +7,6 @@ library quill_delta;
 import 'dart:math' as math;
 
 import 'package:collection/collection.dart';
-import 'package:flutter_quill/utils/hashcode.dart' as hashcode;
 import 'package:quiver/core.dart';
 
 const _attributeEquality = DeepCollectionEquality();
@@ -155,11 +154,11 @@ class Operation {
   @override
   int get hashCode {
     if (_attributes != null && _attributes!.isNotEmpty) {
-      final attrsHash = hashcode.hashObjects(
-          _attributes!.entries.map((e) => hashcode.hash2(e.key, e.value)));
-      return hashcode.hash3(key, value, attrsHash);
+      final attrsHash = hashObjects(
+          _attributes!.entries.map((e) => hash2(e.key, e.value)));
+      return hash3(key, value, attrsHash);
     }
-    return hashcode.hash2(key, value);
+    return hash2(key, value);
   }
 
   @override

lib/utils/hashcode.dart

@@ -1,31 +0,0 @@
-library quiver.hashcode;
-
-/// Generates a hash code for multiple [objects].
-int hashObjects(Iterable objects) =>
-    _finish(objects.fold(0, (h, i) => _combine(h, i.hashCode)));
-
-/// Generates a hash code for two objects.
-int hash2(a, b) => _finish(_combine(_combine(0, a.hashCode), b.hashCode));
-
-/// Generates a hash code for three objects.
-int hash3(a, b, c) => _finish(
-    _combine(_combine(_combine(0, a.hashCode), b.hashCode), c.hashCode));
-
-/// Generates a hash code for four objects.
-int hash4(a, b, c, d) => _finish(_combine(
-    _combine(_combine(_combine(0, a.hashCode), b.hashCode), c.hashCode),
-    d.hashCode));
-
-// Jenkins hash functions
-
-int _combine(int hash, int value) {
-  hash = 0x1fffffff & (hash + value);
-  hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
-  return hash ^ (hash >> 6);
-}
-
-int _finish(int hash) {
-  hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
-  hash = hash ^ (hash >> 11);
-  return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
-}