feat: add quickfix source

Author: lambdalisue

builtin/source/quickfix.ts

@@ -0,0 +1,57 @@
+import { enumerate } from "@core/iterutil/enumerate";
+import * as fn from "@denops/std/function";
+
+import { defineSource, type Source } from "../../source.ts";
+
+type Detail = {
+  bufnr: number;
+  line: number;
+  column: number;
+  quickfix: QuickfixItem;
+};
+
+/**
+ * Provides a source for recently accessed files.
+ *
+ * This source fetches the list of old files stored in the `v:oldfiles` variable
+ * in Vim/Neovim and yields them with each file’s path as `Detail`.
+ *
+ * @returns A source that yields recently accessed files.
+ */
+export function quickfix(): Source<Detail> {
+  return defineSource(async function* (denops, _params, { signal }) {
+    const qflist = await fn.getqflist(denops) as unknown as QuickfixItem[];
+    signal?.throwIfAborted();
+    for (const [id, item] of enumerate(qflist)) {
+      const length = (item.end_col ?? 0) - item.col;
+      const decorations = length > 0 ? [{ column: item.col, length }] : [];
+      yield {
+        id,
+        value: item.text,
+        detail: {
+          bufnr: item.bufnr,
+          line: item.lnum,
+          column: item.col,
+          quickfix: item,
+        },
+        decorations,
+      };
+    }
+  });
+}
+
+type QuickfixItem = {
+  bufnr: number;
+  module: string;
+  lnum: number;
+  end_lnum?: number;
+  col: number;
+  end_col?: number;
+  vcol: boolean;
+  nr: number;
+  pattern: string;
+  text: string;
+  type: string;
+  valid: boolean;
+  user_data: unknown;
+};