🚴 perf: Better lazy eval, avoid trashing GC with empty trees.

Author: make-github-pseudonymous-again

package.json

@@ -220,9 +220,11 @@
     ],
     "rules": {
       "camelcase": "off",
+      "no-bitwise": "off",
       "unicorn/filename-case": "off",
       "unicorn/explicit-length-check": "off",
       "unicorn/no-array-push-push": "off",
+      "unicorn/prefer-math-trunc": "off",
       "unicorn/prefer-node-protocol": "off",
       "unicorn/prefer-module": "off"
     },

src/0-core/_fast/_deepL.js

@@ -8,7 +8,7 @@ import {node3} from '../../2-node/node3.js';
 import {Empty} from '../../3-tree/implementations/0-Empty.js';
 import {Single} from '../../3-tree/implementations/1-Single.js';
 import {Deep} from '../../3-tree/implementations/2-Deep.js';
-import {Lazy} from '../../4-lazy/0-Lazy.js';
+import Lazy from '../../4-lazy/Lazy.js';
 
 /**
  * _fill_right.

src/0-core/_fast/_deepR.js

@@ -1,5 +1,5 @@
 import {One} from '../../1-digit/1-One.js';
-import {Empty} from '../../3-tree/implementations/0-Empty.js';
+import empty from '../../5-api/empty.js';
 import {Single} from '../../3-tree/implementations/1-Single.js';
 import {cache} from '../measure/cache.js';
 import _fill_right from './_fill_right.js';
@@ -8,15 +8,15 @@ export default function _form_by_filling(M, iterable) {
 	const it = iterable[Symbol.iterator]();
 
 	let event = it.next();
-	if (event.done) return new Empty(M);
+	if (event.done) return empty(M);
 	const a = event.value;
 
 	event = it.next();
 	if (event.done) return new Single(M, a);
 	const b = event.value;
 
 	const left = new One(a);
-	const middle = new Empty(cache(M));
+	const middle = empty(cache(M));
 
 	return _fill_right(M, left, middle, b, it);
 }

src/0-core/_fast/_fill_right.js

@@ -1,5 +1,6 @@
 import assert from 'assert';
-import {Empty, Single, Deep} from '../../3-tree/index.js';
+import {Single, Deep} from '../../3-tree/index.js';
+import empty from '../../5-api/empty.js';
 import {Two, One} from '../../1-digit/index.js';
 import {cache} from '../measure/index.js';
 
@@ -11,24 +12,19 @@ export function _from_medium_list(M, list) {
 		case 1:
 			return new Single(M, list[0]);
 		case 2:
-			return new Deep(
-				M,
-				new One(list[0]),
-				new Empty(cache(M)),
-				new One(list[1]),
-			);
+			return new Deep(M, new One(list[0]), empty(cache(M)), new One(list[1]));
 		case 3:
 			return new Deep(
 				M,
 				new Two(list[0], list[1]),
-				new Empty(cache(M)),
+				empty(cache(M)),
 				new One(list[2]),
 			);
 		case 4:
 			return new Deep(
 				M,
 				new Two(list[0], list[1]),
-				new Empty(cache(M)),
+				empty(cache(M)),
 				new Two(list[2], list[3]),
 			);
 	}

src/0-core/_fast/_from_by_filling.js

@@ -1,4 +1,3 @@
-export * from './_fast/index.js';
 export * from './concatenate/index.js';
 export * from './measure/index.js';
 export * from './split/index.js';

src/0-core/_fast/_from_medium_list.js

@@ -2,7 +2,7 @@ import assert from 'assert';
 
 import {Digit} from '../../1-digit/0-Digit.js';
 import {Deep, Tree} from '../../3-tree/index.js';
-import {delay} from '../../4-lazy/index.js';
+import delayTail from '../../4-lazy/delayTail.js';
 
 /**
  * @param {any} M
@@ -18,12 +18,7 @@ export function deepL(M, left, middle, right) {
 	if (left === null) {
 		if (middle.isEmpty()) return right._tree(M);
 
-		return new Deep(
-			M,
-			middle.head()._digit(),
-			delay(() => middle.tail()),
-			right,
-		);
+		return new Deep(M, middle.head()._digit(), delayTail(middle), right);
 	}
 
 	return new Deep(M, left, middle, right);

src/0-core/_fast/index.js

@@ -2,7 +2,7 @@ import assert from 'assert';
 
 import {Digit} from '../../1-digit/0-Digit.js';
 import {Deep, Tree} from '../../3-tree/index.js';
-import {delay} from '../../4-lazy/index.js';
+import delayInit from '../../4-lazy/delayInit.js';
 
 /**
  * @param {any} M
@@ -18,12 +18,7 @@ export function deepR(M, left, middle, right) {
 	if (right === null) {
 		if (middle.isEmpty()) return left._tree(M);
 
-		return new Deep(
-			M,
-			left,
-			delay(() => middle.init()),
-			middle.last()._digit(),
-		);
+		return new Deep(M, left, delayInit(middle), middle.last()._digit());
 	}
 
 	return new Deep(M, left, middle, right);