fix #1521

ParserTools/ParserTools/DefaultLanguageInformation.cs

@@ -2724,7 +2724,7 @@ namespace PascalABCCompiler.Parsers
                         kav.Push('\'');
                     sb.Insert(0, ch);//.Append(Text[i]);
                 }
-                else if (ch == '.' || ch == '^' || ch == '&' || ch == '?')
+                else if (ch == '.' || ch == '^' || ch == '&' || ch == '?' && IsPunctuation(Text, i + 1))
                 {
                     if (ch == '.' && i >= 1 && Text[i - 1] == '.')
                         end = true;

TestSuite/intellisense_tests/question3.pas

@@ -0,0 +1,7 @@
+function f1<T>(self: sequence of T; f: T->T): sequence of T; extensionmethod := self;
+
+begin
+  Arr(0)
+  .f1(i -> 0=0?0:0 )
+  .f1{@(расширение sequence of T) function f1<T>(f: T->T): sequence of T;@}(i->i)
+end.