feat: implement msub tag use case

src/converters/mathml-interfaces-to-latex/mathml-tag-to-latex/Dispatcher.ts

@@ -5,7 +5,6 @@ import {
   MO,
   MN,
   MSqrt,
-  MSup,
   MFenced,
   MFrac,
   MRoot,
@@ -15,6 +14,8 @@ import {
   MError,
   MOver,
   MPhantom,
+  MSup,
+  MSub,
 } from './mathml-tags';
 
 export class Dispatcher {
@@ -42,8 +43,6 @@ export class Dispatcher {
         return new MN(this._value, this._attributes, this._children);
       case 'msqrt':
         return new MSqrt(this._value, this._attributes, this._children);
-      case 'msup':
-        return new MSup(this._value, this._attributes, this._children);
       case 'mfenced':
         return new MFenced(this._value, this._attributes, this._children);
       case 'mfrac':
@@ -60,6 +59,10 @@ export class Dispatcher {
         return new MOver(this._value, this._attributes, this._children);
       case 'mphantom':
         return new MPhantom(this._value, this._attributes, this._children);
+      case 'msup':
+        return new MSup(this._value, this._attributes, this._children);
+      case 'msub':
+        return new MSub(this._value, this._attributes, this._children);
       case 'mrow':
       case 'mpadded':
         return new GenericContentWrapperTag(this._name, this._value, this._attributes, this._children);

src/converters/mathml-interfaces-to-latex/mathml-tag-to-latex/mathml-tags/MSub.ts

@@ -0,0 +1,18 @@
+import { MathMLTag } from './MathMLTag';
+import { BracketWrapper, ParenthesisWrapper } from '../../../../utils/wrappers';
+import { InvalidNumberOfChild } from '../../../../errors';
+
+export class MSub extends MathMLTag {
+  constructor(value: string, attributes: Record<string, string>, children: MathMLTag[]) {
+    super('msub', value, attributes, children);
+  }
+
+  convert(): string {
+    if (this._children.length !== 2) throw new InvalidNumberOfChild(this._name, 2, this._children.length);
+
+    const base = this._children[0].convert();
+    const exponent = this._children[1].convert();
+
+    return `${new ParenthesisWrapper().wrapIfMoreThanOneChar(base)}_${new BracketWrapper().wrap(exponent)}`;
+  }
+}

src/converters/mathml-interfaces-to-latex/mathml-tag-to-latex/mathml-tags/index.ts

@@ -4,7 +4,6 @@ export { MI } from './MI';
 export { MO } from './MO';
 export { MN } from './MN';
 export { MSqrt } from './MSqrt';
-export { MSup } from './MSup';
 export { MFenced } from './MFenced';
 export { MFrac } from './MFrac';
 export { MRoot } from './MRoot';
@@ -14,3 +13,5 @@ export { MEnclose } from './MEnclose';
 export { MError } from './MError';
 export { MOver } from './MOver';
 export { MPhantom } from './MPhantom';
+export { MSup } from './MSup';
+export { MSub } from './MSub';