more on haku, highlighting fixes

static/js/components/literate-programming/eval.js

@@ -79,7 +79,9 @@ export async function evaluate(commands, { error, newOutput }) {
             kind: "output",
             output: {
                 kind: "error",
-                message: [err.toString()],
+                message: [
+                    err.stack.length > 0 ? err.toString() + "\n\n" + err.stack : err.toString(),
+                ],
             },
             outputIndex,
         });

static/js/components/literate-programming/highlight.js

@@ -53,7 +53,13 @@ function tokenize(text, syntax) {
                                 text.substring(start, end),
                             );
                         }
+                        lastMatchEnd = end;
                     }
+                    pushToken(
+                        tokens,
+                        pattern.is.default,
+                        text.substring(lastMatchEnd, match.indices[0][1]),
+                    );
                 } else {
                     pushToken(tokens, pattern.is, match[0]);
                 }