Move "tags" plug into core

packages/plugs/core/core.plug.yaml

@@ -1,5 +1,11 @@
 name: core
 syntax:
+  Hashtag:
+    firstCharacters:
+      - "#"
+    regex: "#[^#\\s]+"
+    styles:
+      color: blue
   NakedURL:
     firstCharacters:
       - "h"
@@ -63,6 +69,16 @@ functions:
     events:
       - page:click
 
+  # Hashtags
+  indexTags:
+    path: "./tags.ts:indexTags"
+    events:
+      - page:index
+  tagComplete:
+    path: "./tags.ts:tagComplete"
+    events:
+      - page:complete
+
   # Full text search
   searchIndex:
     path: ./search.ts:index

packages/plugs/core/tags.ts

@@ -0,0 +1,39 @@
+import { collectNodesOfType } from "@silverbulletmd/common/tree";
+import {
+  batchSet,
+  queryPrefix,
+} from "@silverbulletmd/plugos-silverbullet-syscall";
+import { matchBefore } from "@silverbulletmd/plugos-silverbullet-syscall/editor";
+import type { IndexTreeEvent } from "@silverbulletmd/web/app_event";
+import { removeQueries } from "../query/util";
+
+// Key space
+// ht:TAG => true (for completion)
+
+export async function indexTags({ name, tree }: IndexTreeEvent) {
+  removeQueries(tree);
+  let allTags = new Set<string>();
+  collectNodesOfType(tree, "Hashtag").forEach((n) => {
+    allTags.add(n.children![0].text!);
+  });
+  batchSet(
+    name,
+    [...allTags].map((t) => ({ key: `ht:${t}`, value: t }))
+  );
+}
+
+export async function tagComplete() {
+  let prefix = await matchBefore("#[^#\\s]+");
+  //   console.log("Running tag complete", prefix);
+  if (!prefix) {
+    return null;
+  }
+  let allTags = await queryPrefix(`ht:${prefix.text}`);
+  return {
+    from: prefix.from,
+    options: allTags.map((tag) => ({
+      label: tag.value,
+      type: "tag",
+    })),
+  };
+}