Fix names with '$' to not conflict with operators or internal helpers

frog/parser.dart

Index: frog/parser.dart
diff --git a/frog/parser.dart b/frog/parser.dart
index a1ca3292636b9eca428d8eb79f12a9ca370817f8..924118da0c9d65d28192e518f82f93d814998f30 100644
--- a/frog/parser.dart
+++ b/frog/parser.dart
@@ -1271,7 +1271,7 @@ class Parser {
         if (!includeOperators) return null;
         _eat(TokenKind.GET);
         if (_peekIdentifier()) {
-          name = 'get\$${identifier().name}';
+          name = 'get:${identifier().name}';
         } else {
           name = 'get';
         }
@@ -1280,7 +1280,7 @@ class Parser {
         if (!includeOperators) return null;
         _eat(TokenKind.SET);
         if (_peekIdentifier()) {
-          name = 'set\$${identifier().name}';
+          name = 'set:${identifier().name}';
         } else {
           name = 'set';
         }
@@ -1290,7 +1290,7 @@ class Parser {
         _eat(TokenKind.OPERATOR);
         var kind = _peek();
         if (kind == TokenKind.NEGATE) {
-          name = '\$negate';
+          name = ':negate';
           _next();
         } else {
           name = TokenKind.binaryMethodName(kind);