fix: fixed #2116

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 - A closing parenthesis following a function application would be ignored, 
   i.e. `(f(x))` would be parsed as `(f(x)`.
+- **#2116** Pressing the "/" key after an expression ending with a superscript would
+  not recognize the left argument as a numerator.
 
 ### Improvements
 

src/editor-model/commands-move.ts

@@ -77,7 +77,7 @@ function moveToSuperscript(model: ModelPrivate): boolean {
 
   if (target.subsupPlacement === undefined) {
     // This atom can't have a superscript/subscript:
-    // add an adjacent `msubsup` atom instead.
+    // add an adjacent `subsup` atom instead.
     if (target.rightSibling?.type !== 'subsup') {
       target.parent!.addChildAfter(
         new SubsupAtom({ style: target.computedStyle }),
@@ -112,7 +112,7 @@ function moveToSubscript(model: ModelPrivate): boolean {
 
   if (target.subsupPlacement === undefined) {
     // This atom can't have a superscript/subscript:
-    // add an adjacent `msubsup` atom instead.
+    // add an adjacent `subsup` atom instead.
     if (model.at(model.position + 1)?.type !== 'subsup') {
       target.parent!.addChildAfter(
         new SubsupAtom({ style: model.at(model.position).computedStyle }),

src/editor-model/delete.ts

@@ -271,7 +271,7 @@ function onDelete(
     if (branch && atom.hasEmptyBranch(branch)) atom.removeBranch(branch);
 
     if (!atom.hasChildren) {
-      // We've removed the last branch of a msubsup
+      // We've removed the last branch of a subsup
       const pos =
         direction === 'forward'
           ? model.offsetOf(atom)

src/editor/shortcuts.ts

@@ -42,7 +42,7 @@ function validateShortcut(
   // Find first sibling left which is not a placeholder or subsup
   let sibling = siblings[0]; // sibling immediately left
   let index = 0;
-  while (sibling?.type && /msubsup|placeholder/.test(sibling.type)) {
+  while (sibling?.type && /^(subsup|placeholder)$/.test(sibling.type)) {
     index += 1;
     sibling = siblings[index];
   }