in stacking added back exceptions when items

feature removed during reimplementation 6f9fee6

.vscode/launch.json

@@ -249,6 +249,18 @@
 				"request": "launch",
 				"type": "node"
 			},
+			{
+				"args":
+					[ 
+						"--runInBand",
+						"stacking/createOrAddToStacksUniformly/test.js"
+					],
+				"disableOptimisticBPs": true,
+				"name": "stacking createOrAddToStacksUniformly jest",
+				"program": "${workspaceFolder}/node_modules/jest/bin/jest.js",
+				"request": "launch",
+				"type": "node"
+			},
 			{
 				"args":
 					[
@@ -276,10 +288,10 @@
 				"args":
 					[ 
 						"--runInBand",
-						"stacking/createStackWhenIdentifierOrItemOrLevelOrAddWhenStack/createGetItemWithIdentifier/test.js"
+						"stacking/createStackWhenIdentifierOrItemOrLevelOrAddWhenStack/createItemLookup/test.js"
 					],
 				"disableOptimisticBPs": true,
-				"name": "stacking createStackWhenIdentifierOrItemOrLevelOrAddWhenStack createGetItemWithIdentifier jest",
+				"name": "stacking createStackWhenIdentifierOrItemOrLevelOrAddWhenStack createItemLookup jest",
 				"program": "${workspaceFolder}/node_modules/jest/bin/jest.js",
 				"request": "launch",
 				"type": "node"

package.json

@@ -90,5 +90,5 @@
 		"spellcheck": "find -type f \\( -name \"*.js\" -or -name \"*.md\" \\) ! -path \"./dist/*\" ! -path \"./dist/**/*\" ! -path \"./node_modules/**/*\" ! -path \"./test-coverage/**/*\" -exec npx cspell {} +",
 		"test": "npx jest --runInBand"
 	},
-	"version": "6.0.2"
+	"version": "6.1.0"
 }

stacking/createStackWhenIdentifierOrItemOrLevelOrAddWhenStack/createItemLookup/createForLevelOrStack.js

@@ -0,0 +1,78 @@
+/* Copyright (c) 2019 Graham Dyson. All Rights Reserved.
+This library is free software, licensed 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. You should have received a copy of the GNU General Public License along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+
+require("array.prototype.flatMap")
+.shim();
+
+module.exports =
+	levelOrStack => {
+		const itemsByIdentifier = new Map(generateKeyValuePairs());
+
+		return (
+			{
+				getIdentifiersNotUsed,
+				getItemWithIdentifier,
+			}
+		);
+
+		function * generateKeyValuePairs() {
+			for (const identifierOrItemOrLevel of levelOrStack)
+				if (Array.isArray(identifierOrItemOrLevel))
+					for (const identifierOrItem of identifierOrItemOrLevel)
+						yield getKeyValuePairForIdentifierOrItem(identifierOrItem);
+				else
+					yield getKeyValuePairForIdentifierOrItem(identifierOrItemOrLevel);
+		}
+
+		function getIdentifiersNotUsed() {
+			return (
+				getIterableAsArrayWhenHasItems(generate())
+				||
+				null
+			);
+
+			function * generate() {
+				for (const { isUsed, item } of itemsByIdentifier.values())
+					if (!isUsed)
+						yield getIdentifier(item);
+			}
+
+			function getIterableAsArrayWhenHasItems(
+				iterable,
+			) {
+				const array = [ ...iterable ];
+
+				return array.length && array;
+			}
+		}
+
+		function getItemWithIdentifier(
+			identifier,
+		) {
+			const itemAndIsUsed = itemsByIdentifier.get(identifier);
+
+			if (itemAndIsUsed) {
+				itemAndIsUsed.isUsed = true;
+
+				return itemAndIsUsed.item;
+			} else
+				return null;
+		}
+	};
+
+function getKeyValuePairForIdentifierOrItem(
+	identifierOrItem,
+) {
+	return (
+		[
+			getIdentifier(identifierOrItem),
+			{ item: identifierOrItem },
+		]
+	);
+}
+
+function getIdentifier(
+	identifierOrItem,
+) {
+	return identifierOrItem.id || identifierOrItem;
+}

stacking/createStackWhenIdentifierOrItemOrLevelOrAddWhenStack/createItemLookup/createForSingle.js

@@ -0,0 +1,32 @@
+/* Copyright (c) 2019 Graham Dyson. All Rights Reserved.
+This library is free software, licensed 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. You should have received a copy of the GNU General Public License along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+
+module.exports =
+	({
+		identifier,
+		item,
+	}) => {
+		let used = false;
+
+		return (
+			{
+				getIdentifiersNotUsed,
+				getItemWithIdentifier,
+			}
+		);
+
+		function getIdentifiersNotUsed() {
+			return used ? null : [ identifier ];
+		}
+
+		function getItemWithIdentifier(
+			targetIdentifier,
+		) {
+			if (identifier === targetIdentifier) {
+				used = true;
+
+				return item;
+			} else
+				return null;
+		}
+	};

stacking/createStackWhenIdentifierOrItemOrLevelOrAddWhenStack/createItemLookup/index.js

@@ -0,0 +1,54 @@
+/* Copyright (c) 2019 Graham Dyson. All Rights Reserved.
+This library is free software, licensed 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. You should have received a copy of the GNU General Public License along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+
+const
+	createForLevelOrStack = require("./createForLevelOrStack"),
+	createForSingle = require("./createForSingle");
+
+module.exports =
+	identifierOrItemOrLevelOrStack => {
+		return (
+			whenNoValue()
+			||
+			whenLevelOrStack()
+			||
+			whenItem()
+			||
+			createForSingle({
+				identifier: identifierOrItemOrLevelOrStack,
+				item: identifierOrItemOrLevelOrStack,
+			})
+		);
+
+		function whenNoValue() {
+			return (
+				!identifierOrItemOrLevelOrStack
+				&&
+				{
+					getIdentifiersNotUsed: () => null,
+					// identifier parameter intentionally ignored as there are no items
+					// eslint-disable-next-line no-unused-vars
+					getItemWithIdentifier: identifier => null,
+				}
+			);
+		}
+
+		function whenLevelOrStack() {
+			return (
+				Array.isArray(identifierOrItemOrLevelOrStack)
+				&&
+				createForLevelOrStack(identifierOrItemOrLevelOrStack)
+			);
+		}
+
+		function whenItem() {
+			return (
+				identifierOrItemOrLevelOrStack.id
+				&&
+				createForSingle({
+					identifier: identifierOrItemOrLevelOrStack.id,
+					item: identifierOrItemOrLevelOrStack,
+				})
+			);
+		}
+	};