feat: use item belt to simplify

Author: lambdalisue

denops/fall/component/help.ts

@@ -6,6 +6,7 @@ import * as buffer from "jsr:@denops/std@^7.3.2/buffer";
 import type { Dimension } from "jsr:@vim-fall/std@^0.4.0/coordinator";
 
 import { BaseComponent } from "./_component.ts";
+import { ItemBelt } from "../lib/item_belt.ts";
 
 export type Page = {
   readonly title?: string;
@@ -14,31 +15,27 @@ export type Page = {
 };
 
 export class HelpComponent extends BaseComponent {
-  #page = 1;
-  #pages: readonly Page[] = [];
+  readonly #pages = new ItemBelt<Page>([]);
   #modifiedContent = true;
 
   get page(): number {
-    return this.#page;
+    return this.#pages.index + 1;
   }
 
   set page(page: number | "$") {
-    if (page === "$" || page >= this.#pages.length) {
-      page = this.#pages.length;
-    } else if (page < 1) {
-      page = 1;
+    if (page === "$") {
+      page = this.#pages.count;
     }
-    this.#page = page;
+    this.#pages.index = page - 1;
     this.#modifiedContent = true;
   }
 
   get pages(): readonly Page[] {
-    return this.#pages;
+    return this.#pages.items;
   }
 
   set pages(pages: readonly Page[]) {
-    this.#pages = pages;
-    this.page = this.#page;
+    this.#pages.items = pages;
     this.#modifiedContent = true;
   }
 
@@ -91,7 +88,7 @@ export class HelpComponent extends BaseComponent {
 
     const { bufnr, dimension: { width } } = this.info;
 
-    const page = this.#pages.at(this.#page - 1);
+    const page = this.#pages.current;
     const content = [
       await this.#buildNavigationHeader(denops, width, { signal }),
       ...(page?.content ?? []),
@@ -129,7 +126,7 @@ export class HelpComponent extends BaseComponent {
     const prev = mappings.find((m) => m.rhs === "<Plug>(fall-help-prev)");
     const next = mappings.find((m) => m.rhs === "<Plug>(fall-help-next)");
     const navigator = [prev?.lhs, next?.lhs].filter((v) => !!v).join(" / ");
-    const pager = `Page ${this.#page}/${this.#pages.length}`;
+    const pager = `Page ${this.page}/${this.#pages.count}`;
     const spacer = " ".repeat(width - pager.length - navigator.length);
     return `${pager}${spacer}${navigator}`;
   }

denops/fall/processor/collect.ts

@@ -16,13 +16,13 @@ export type CollectProcessorOptions = {
 };
 
 export class CollectProcessor<T extends Detail> implements Disposable {
+  readonly #controller: AbortController = new AbortController();
+  readonly #items: IdItem<T>[] = [];
   readonly #source: Source<T>;
   readonly #threshold: number;
   readonly #chunkSize: number;
-  readonly #controller: AbortController = new AbortController();
   #processing?: Promise<void>;
   #paused?: PromiseWithResolvers<void>;
-  readonly #items: IdItem<T>[] = [];
 
   constructor(
     source: Source<T>,

denops/fall/processor/match.ts

@@ -5,6 +5,7 @@ import type { Detail, IdItem } from "jsr:@vim-fall/std@^0.4.0/item";
 import type { Matcher, MatchParams } from "jsr:@vim-fall/std@^0.4.0/matcher";
 
 import { Chunker } from "../lib/chunker.ts";
+import { ItemBelt } from "../lib/item_belt.ts";
 import { dispatch } from "../event.ts";
 
 const INTERVAL = 0;
@@ -19,7 +20,7 @@ export type MatchProcessorOptions = {
 };
 
 export class MatchProcessor<T extends Detail> implements Disposable {
-  readonly #matchers: readonly [Matcher<T>, ...Matcher<T>[]];
+  readonly #matchers: ItemBelt<Matcher<T>>;
   readonly #interval: number;
   readonly #threshold: number;
   readonly #chunkSize: number;
@@ -28,42 +29,39 @@ export class MatchProcessor<T extends Detail> implements Disposable {
   #processing?: Promise<void>;
   #reserved?: () => void;
   #items: IdItem<T>[] = [];
-  #matcherIndex = 0;
 
   constructor(
-    filters: readonly [Matcher<T>, ...Matcher<T>[]],
+    matchers: readonly [Matcher<T>, ...Matcher<T>[]],
     options: MatchProcessorOptions = {},
   ) {
-    this.#matchers = filters;
+    this.#matchers = new ItemBelt(matchers);
     this.#interval = options.interval ?? INTERVAL;
     this.#threshold = options.threshold ?? THRESHOLD;
     this.#chunkSize = options.chunkSize ?? CHUNK_SIZE;
     this.#incremental = options.incremental ?? false;
   }
 
   get #matcher(): Matcher<T> {
-    return this.#matchers[this.#matcherIndex];
+    return this.#matchers.current!;
   }
 
   get items(): IdItem<T>[] {
     return this.#items;
   }
 
   get matcherCount(): number {
-    return this.#matchers.length;
+    return this.#matchers.count;
   }
 
   get matcherIndex(): number {
-    return this.#matcherIndex;
+    return this.#matchers.index;
   }
 
   set matcherIndex(index: number | "$") {
-    if (index === "$" || index >= this.#matchers.length) {
-      index = this.#matchers.length - 1;
-    } else if (index < 0) {
-      index = 0;
+    if (index === "$") {
+      index = this.#matchers.count;
     }
-    this.#matcherIndex = index;
+    this.#matchers.index = index;
   }
 
   #validateAvailability(): void {

denops/fall/processor/preview.ts

@@ -5,39 +5,37 @@ import type {
   PreviewParams,
 } from "jsr:@vim-fall/std@^0.4.0/previewer";
 
+import { ItemBelt } from "../lib/item_belt.ts";
 import { dispatch } from "../event.ts";
 
 export class PreviewProcessor<T extends Detail> implements Disposable {
-  readonly #previewers: Previewer<T>[];
   readonly #controller: AbortController = new AbortController();
+  readonly #previewers: ItemBelt<Previewer<T>>;
   #processing?: Promise<void>;
   #reserved?: () => void;
   #item: PreviewItem | undefined = undefined;
-  #previewerIndex = 0;
 
-  constructor(previewers: Previewer<T>[]) {
-    this.#previewers = previewers;
+  constructor(previewers: readonly Previewer<T>[]) {
+    this.#previewers = new ItemBelt(previewers);
   }
 
   get #previewer(): Previewer<T> | undefined {
-    return this.#previewers[this.#previewerIndex];
+    return this.#previewers.current;
   }
 
   get previewerCount(): number {
-    return this.#previewers.length;
+    return this.#previewers.count;
   }
 
   get previewerIndex(): number {
-    return this.#previewerIndex;
+    return this.#previewers.index;
   }
 
   set previewerIndex(index: number | "$") {
-    if (index === "$" || index >= this.#previewers.length) {
-      index = this.#previewers.length - 1;
-    } else if (index < 0) {
-      index = 0;
+    if (index === "$") {
+      index = this.#previewers.count;
     }
-    this.#previewerIndex = index;
+    this.#previewers.index = index;
   }
 
   get item(): PreviewItem | undefined {

denops/fall/processor/render.ts

@@ -7,6 +7,7 @@ import type {
 import type { Renderer } from "jsr:@vim-fall/std@^0.4.0/renderer";
 
 import { adjustOffset } from "../lib/adjust_offset.ts";
+import { ItemBelt } from "../lib/item_belt.ts";
 import { dispatch } from "../event.ts";
 
 const HEIGHT = 10;
@@ -18,46 +19,43 @@ export type RenderProcessorOptions = {
 };
 
 export class RenderProcessor<T extends Detail> implements Disposable {
-  readonly #renderers: Renderer<T>[];
+  readonly #controller: AbortController = new AbortController();
+  readonly #renderers: ItemBelt<Renderer<T>>;
   #height: number;
   #scrollOffset: number;
-  readonly #controller: AbortController = new AbortController();
   #processing?: Promise<void>;
   #reserved?: () => void;
   #items: DisplayItem<T>[] = [];
   #itemCount: number = 0;
   #cursor: number = 0;
   #offset: number = 0;
-  #rendererIndex: number = 0;
 
   constructor(
-    renderers: Renderer<T>[],
+    renderers: readonly Renderer<T>[],
     options: RenderProcessorOptions = {},
   ) {
-    this.#renderers = renderers;
+    this.#renderers = new ItemBelt(renderers);
     this.#height = options.height ?? HEIGHT;
     this.#scrollOffset = options.scrollOffset ?? SCROLL_OFFSET;
   }
 
   get #renderer(): Renderer<T> | undefined {
-    return this.#renderers.at(this.#rendererIndex);
+    return this.#renderers.current;
   }
 
   get rendererCount(): number {
-    return this.#renderers.length;
+    return this.#renderers.count;
   }
 
   get rendererIndex(): number {
-    return this.#rendererIndex;
+    return this.#renderers.index;
   }
 
   set rendererIndex(index: number | "$") {
-    if (index === "$" || index >= this.rendererCount) {
-      index = this.rendererCount - 1;
-    } else if (index < 0) {
-      index = 0;
+    if (index === "$") {
+      index = this.#renderers.count;
     }
-    this.#rendererIndex = index;
+    this.#renderers.index = index;
   }
 
   get items() {

denops/fall/processor/sort.ts

@@ -2,39 +2,37 @@ import type { Denops } from "jsr:@denops/std@^7.3.2";
 import type { Detail, IdItem } from "jsr:@vim-fall/std@^0.4.0/item";
 import type { Sorter } from "jsr:@vim-fall/std@^0.4.0/sorter";
 
+import { ItemBelt } from "../lib/item_belt.ts";
 import { dispatch } from "../event.ts";
 
 export class SortProcessor<T extends Detail> implements Disposable {
-  readonly #sorters: Sorter<T>[];
   readonly #controller: AbortController = new AbortController();
+  readonly #sorters: ItemBelt<Sorter<T>>;
   #processing?: Promise<void>;
   #reserved?: () => void;
   #items: IdItem<T>[] = [];
-  #sorterIndex: number = 0;
 
-  constructor(sorters: Sorter<T>[]) {
-    this.#sorters = sorters;
+  constructor(sorters: readonly Sorter<T>[]) {
+    this.#sorters = new ItemBelt(sorters);
   }
 
   get #sorter(): Sorter<T> | undefined {
-    return this.#sorters.at(this.#sorterIndex);
+    return this.#sorters.current;
   }
 
   get sorterCount(): number {
-    return this.#sorters.length;
+    return this.#sorters.count;
   }
 
   get sorterIndex(): number {
-    return this.#sorterIndex;
+    return this.#sorters.index;
   }
 
   set sorterIndex(index: number | "$") {
-    if (index === "$" || index >= this.sorterCount) {
-      index = this.sorterCount - 1;
-    } else if (index < 0) {
-      index = 0;
+    if (index === "$") {
+      index = this.#sorters.count;
     }
-    this.#sorterIndex = index;
+    this.#sorters.index = index;
   }
 
   get items() {