feat: highlight matched keywords in search results

docs_v1.0/doc_wasm/index.html

@@ -146,6 +146,12 @@ function escapeHtml(s) {
   return s.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;');
 }
 
+function highlightText(text, query) {
+  var escaped = escapeHtml(text);
+  var re = new RegExp('(' + query.replace(/[.*+?^${}()|[\]\\]/g, '\\$&') + ')', 'gi');
+  return escaped.replace(re, '<mark style="background:#ffeb3b;color:#000;padding:0 2px;border-radius:2px">$1</mark>');
+}
+
 async function fulltextSearch(q) {
   el.innerHTML = '<p>Searching...</p>';
   var results = [];
@@ -173,7 +179,7 @@ async function fulltextSearch(q) {
     html += '<p style="margin:4px 0"><a href="#" onclick="loadDoc(\'' + r.module + '\');return false" style="font-weight:600">'
          + r.module + ' ' + escapeHtml(r.title) + '</a> <span style="color:#888;font-size:12px">line ' + r.line + '</span><br>'
          + '<code style="background:#f5f5f5;padding:2px 6px;border-radius:3px;font-size:12px;display:inline-block;max-width:100%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap">'
-         + escapeHtml(r.text) + '</code></p>';
+         + highlightText(r.text, q) + '</code></p>';
   }
   el.innerHTML = html;
 }