change syntax

readme.md

@@ -240,7 +240,7 @@ If the key of the nested reference includes the "." delimiter, please wrap the w
 }
 ```
 
-`` $address.`city.code[0]` `` can reference the object
+`` $address.`city.code`[0] `` can reference the object
 ```javascript
 {
   address: {

src/operand/__test__/unit/reference.test.ts

@@ -65,8 +65,8 @@ describe('Operand - Value', () => {
       ['RefC.subA', 2],
       ['RefC.subB.subSubA', 3],
       ['RefC.`subC.dotKey`.subSubC', 4],
-      ['RefC.`subD.dotKey[0]`.subSubD', 5],
-      ['RefC.`subD.dotKey[0]`.subSubE[0].subSubSubE', 6],
+      ['RefC.`subD.dotKey`[0].subSubD', 5],
+      ['RefC.`subD.dotKey`[0].subSubE[0].subSubSubE', 6],
       // Missing
       ['RefB', undefined],
       ['RefC.subC', undefined],

src/operand/reference.ts

@@ -9,26 +9,31 @@ type Keys = (string | number)[]
 const keyWithArrayIndexRegex =
   /^(?<currentKey>[^[\]]+?)(?<indexes>(?:\[\d+])+)?$/
 const arrayIndexRegex = /\[(\d+)]/g
+
+const parseBacktickWrappedKey = (key: string) =>
+  key.startsWith('`') && key.endsWith('`') ? key.slice(1, -1) : key
+
 const parseKey = (key: string): Keys => {
-  const keys = key.match(/(`.+`|[^`.]+)/g)
+  const keys = key.match(/(`.+`(\[\d+\])*|[^`.]+)/g)
   return !keys
     ? []
     : keys.flatMap((key) => {
-        if (key.startsWith('`') && key.endsWith('`')) {
-          key = key.slice(1, -1)
-        }
-        const parseResult = keyWithArrayIndexRegex.exec(key)
+        const unwrappedKey = parseBacktickWrappedKey(key)
         const keys: Keys = []
+        const parseResult = keyWithArrayIndexRegex.exec(unwrappedKey)
         if (parseResult) {
-          keys.push(parseResult?.groups?.currentKey ?? key)
+          const extractedKey = parseBacktickWrappedKey(
+            parseResult?.groups?.currentKey ?? unwrappedKey
+          )
+          keys.push(extractedKey)
           const rawIndexes = parseResult?.groups?.indexes
           if (rawIndexes) {
             for (const indexResult of rawIndexes.matchAll(arrayIndexRegex)) {
               keys.push(parseInt(indexResult[1]))
             }
           }
         } else {
-          keys.push(key)
+          keys.push(unwrappedKey)
         }
         return keys
       })