This is true under the hood of most static language IDEs as well. If they are not using a custom compiler (like JDT Core in Eclipse) they end up implementing a

This is true under the hood of most static language IDEs as well. If they are not using a custom compiler (like JDT Core in Eclipse) they end up implementing a partial compiler to support features beyond ctags. ctags itself is the tokenizing and partial parsing step of a compiler.