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/find.js

@@ -0,0 +1,138 @@
+// Find and replace in either editor (MARK-06).
+import {
+  SearchQuery as TextQuery,
+  findNext as nextText,
+  findPrevious as previousText,
+  replaceAll as allText,
+  replaceNext as oneText,
+  setSearchQuery,
+} from '@codemirror/search'
+import {
+  SearchQuery as DocQuery,
+  findNext as nextDoc,
+  findPrev as previousDoc,
+  replaceAll as allDoc,
+  replaceNext as oneDoc,
+  setSearchState,
+} from 'prosemirror-search'
+import { TextSelection } from '@milkdown/kit/prose/state'
+
+/** Why a pattern fails under the editors' `gmu` flags. */
+function broken(spec) {
+  if (!spec.regexp || !spec.search) return null
+  try {
+    new RegExp(spec.search, 'gmu')
+    return null
+  } catch (error) {
+    return error.message
+  }
+}
+
+/** Whether two specs find the same hits. */
+export function sameQuery(a, b) {
+  return ['search', 'caseSensitive', 'regexp', 'wholeWord'].every((key) => a[key] === b[key])
+}
+
+/** One character's width at `pos`: two for a surrogate pair. */
+function width(doc, pos) {
+  const next = doc.textBetween(pos, Math.min(pos + 2, doc.content.size), '\n', '\n')
+  return next.codePointAt(0) > 0xffff ? 2 : 1
+}
+
+/** Where the selection stands among `ranges`. */
+function standing(ranges, from, to) {
+  const at = ranges.findIndex((range) => range.from === from && range.to === to)
+  return { current: at < 0 ? null : at, total: ranges.length }
+}
+
+/** Find in Milkdown's view; `prosemirror-search` is installed there. */
+export function docFinder(view) {
+  let spec = { search: '' }
+  const query = () => new DocQuery(spec)
+  const ranges = () => {
+    const found = []
+    const asked = query()
+    if (!asked.valid) return found
+    const { doc } = view.state
+    for (let at = 0; ;) {
+      const hit = asked.findNext(view.state, at)
+      // Mid-pair, a Unicode pattern answers before `at`.
+      if (!hit || hit.from < at) return found
+      found.push(hit)
+      at = hit.to > hit.from ? hit.to : hit.to + width(doc, hit.to)
+    }
+  }
+  const status = () => {
+    const error = broken(spec)
+    if (error) return { error }
+    const { from, to } = view.state.selection
+    return standing(ranges(), from, to)
+  }
+  const run = (command) => command(view.state, view.dispatch)
+  return {
+    seek(next) {
+      spec = next
+      const { from } = view.state.selection
+      const tr = setSearchState(view.state.tr, query())
+      // From the hit's start: the hit stays while typing.
+      tr.setSelection(TextSelection.near(tr.doc.resolve(from)))
+      view.dispatch(tr)
+      if (query().valid) run(nextDoc)
+      return status()
+    },
+    step(forward) {
+      if (query().valid) run(forward ? nextDoc : previousDoc)
+      return status()
+    },
+    replace(all) {
+      if (query().valid) run(all ? allDoc : oneDoc)
+      return status()
+    },
+    clear() {
+      spec = { search: '' }
+      view.dispatch(setSearchState(view.state.tr, query()))
+    },
+  }
+}
+
+/** Find in CodeMirror; its `search()` extension is installed there. */
+export function textFinder(view) {
+  let spec = { search: '' }
+  const valid = () => new TextQuery(spec).valid
+  const ranges = () => {
+    const found = []
+    const asked = new TextQuery(spec)
+    if (!asked.valid) return found
+    const cursor = asked.getCursor(view.state)
+    for (let next = cursor.next(); !next.done; next = cursor.next()) found.push(next.value)
+    return found
+  }
+  const status = () => {
+    const error = broken(spec)
+    if (error) return { error }
+    const { from, to } = view.state.selection.main
+    return standing(ranges(), from, to)
+  }
+  return {
+    seek(next) {
+      spec = next
+      const selection = { anchor: view.state.selection.main.from }
+      view.dispatch({ effects: setSearchQuery.of(new TextQuery(spec)), selection })
+      // CodeMirror opens its own panel for invalid queries.
+      if (valid()) nextText(view)
+      return status()
+    },
+    step(forward) {
+      if (valid()) (forward ? nextText : previousText)(view)
+      return status()
+    },
+    replace(all) {
+      if (valid()) (all ? allText : oneText)(view)
+      return status()
+    },
+    clear() {
+      spec = { search: '' }
+      view.dispatch({ effects: setSearchQuery.of(new TextQuery(spec)) })
+    },
+  }
+}