Indexer is something that has identifier(parameter) followed by [ with or without type annotation

Fixes #197

Author: sheetalkamat

TypeScript.YAML-tmLanguage

@@ -529,7 +529,7 @@ repository:
 
   indexer-declaration:
     name: meta.indexer.declaration.ts
-    begin: (?:(?<!\.|\$)\b(readonly)\s*)?(\[)
+    begin: (?:(?<!\.|\$)\b(readonly)\s*)?(\[)(?=\s*[_$[:alpha:]][_$[:alnum:]]*\s*[:\]])
     beginCaptures:
       '1': { name: storage.modifier.ts }
       '2': { name: meta.brace.square.ts }
@@ -543,7 +543,7 @@ repository:
 
   indexer-parameter:
     name: meta.indexer.parameter.ts
-    match: ([_$[:alpha:]][_$[:alnum:]]*)(?=\:)
+    match: ([_$[:alpha:]][_$[:alnum:]]*)
     captures:
       '1': { name: variable.parameter.ts}
 

TypeScript.tmLanguage

@@ -1735,7 +1735,7 @@
         <key>name</key>
         <string>meta.indexer.declaration.ts</string>
         <key>begin</key>
-        <string>(?:(?&lt;!\.|\$)\b(readonly)\s*)?(\[)</string>
+        <string>(?:(?&lt;!\.|\$)\b(readonly)\s*)?(\[)(?=\s*[_$[:alpha:]][_$[:alnum:]]*\s*[:\]])</string>
         <key>beginCaptures</key>
         <dict>
           <key>1</key>
@@ -1781,7 +1781,7 @@
         <key>name</key>
         <string>meta.indexer.parameter.ts</string>
         <key>match</key>
-        <string>([_$[:alpha:]][_$[:alnum:]]*)(?=\:)</string>
+        <string>([_$[:alpha:]][_$[:alnum:]]*)</string>
         <key>captures</key>
         <dict>
           <key>1</key>

TypeScriptReact.tmLanguage

@@ -1739,7 +1739,7 @@
         <key>name</key>
         <string>meta.indexer.declaration.tsx</string>
         <key>begin</key>
-        <string>(?:(?&lt;!\.|\$)\b(readonly)\s*)?(\[)</string>
+        <string>(?:(?&lt;!\.|\$)\b(readonly)\s*)?(\[)(?=\s*[_$[:alpha:]][_$[:alnum:]]*\s*[:\]])</string>
         <key>beginCaptures</key>
         <dict>
           <key>1</key>
@@ -1785,7 +1785,7 @@
         <key>name</key>
         <string>meta.indexer.parameter.tsx</string>
         <key>match</key>
-        <string>([_$[:alpha:]][_$[:alnum:]]*)(?=\:)</string>
+        <string>([_$[:alpha:]][_$[:alnum:]]*)</string>
         <key>captures</key>
         <dict>
           <key>1</key>