Fix the case when an emphasis start and end token are not of the same…

… length.

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@openwebwork/codemirror-lang-pg",
-    "version": "0.0.1-beta.16",
+    "version": "0.0.1-beta.17",
     "description": "PG language support for CodeMirror",
     "author": "The WeBWorK Project",
     "license": "MIT",

src/pgml-parse.ts

@@ -379,14 +379,14 @@ export class PGMLParse {
         const type = BlockDefs[token.substring(0, 1)]?.type;
         let block = this.block;
         if (block && block.type === type) {
-            block.to += block.token?.length ?? 1;
+            block.to += token.length;
             this.Terminate();
             return;
         }
         while (block?.type !== 'root') {
             if (block && block.prev?.type === type) {
                 this.End(`end of ${type ?? ''}`, block);
-                block.to += block.token?.length ?? 1;
+                block.to += token.length;
                 this.Terminate();
                 return;
             }

src/pgml.ts

@@ -336,7 +336,7 @@ const pgmlFormat = (block: Item, offset: number): Element<Type>[] => {
         const lastChild = block.stack?.at(-1);
         if (lastChild instanceof Item && block.to === lastChild.to)
             children.push(elt(Type.PGMLError, block.to + offset, block.to + offset));
-        else children.push(elt(Type.EmphasisMark, block.to - (block.token?.length ?? 1) + offset, block.to + offset));
+        else children.push(elt(Type.EmphasisMark, children.slice(-1)[0].to, block.to + offset));
         return [
             elt(
                 block.type === 'bold' ? Type.StrongEmphasis : Type.Emphasis,