Ely Office: six offline-first desktop apps in Rust and GPUI

ElyDoc, ElyTable, ElyShow (LibreOfficeKit), ElyPDF (MuPDF), ElyTree (Git),
ElyMark (Milkdown and CodeMirror in CEF). ElyMail and ElyAgent follow.

apps/ely-mark/web/src/style.js

@@ -0,0 +1,41 @@
+// The document's own markers, so blocks write back unchanged.
+import { unified } from 'unified'
+import remarkParse from 'remark-parse'
+import { visit } from 'unist-util-visit'
+
+/** remark-stringify options most of `text` already uses. */
+export function style(text) {
+  const votes = {}
+  const vote = (key, value) => {
+    votes[key] ??= new Map()
+    votes[key].set(value, (votes[key].get(value) ?? 0) + 1)
+  }
+  visit(unified().use(remarkParse).parse(text), (node) => {
+    const at = node.position?.start.offset
+    if (at === undefined) return
+    const head = text.slice(at, at + 12)
+    switch (node.type) {
+      case 'listItem': {
+        const ordered = /^\d+([.)])/.exec(head)
+        if (ordered) vote('bulletOrdered', ordered[1])
+        else if (/^[*+-]/.test(head)) vote('bullet', head[0])
+        break
+      }
+      case 'emphasis':
+      case 'strong':
+        vote(node.type, head[0])
+        break
+      case 'code':
+        if (/^[`~]/.test(head)) vote('fence', head[0])
+        break
+      case 'thematicBreak':
+        vote('rule', head[0])
+        break
+      case 'heading':
+        if (node.depth <= 2) vote('setext', head[0] !== '#')
+        break
+    }
+  })
+  const most = (key) => [...votes[key].entries()].sort((a, b) => b[1] - a[1])[0][0]
+  return Object.fromEntries(Object.keys(votes).map((key) => [key, most(key)]))
+}