The most of advanced code editors (IntelliJ IDEA, Eclipse, etc...) index a full project structure giving us abilities to:
- go to a file where declaration of current variable, constant or other entity is declared Goto Declaration
- include variables and/or files at certain points of code by auto-completing the variables/entities/filenames with paths Project-Wide Auto Completion
- all other advantages of project indexing go here...
And it could be optional so that "Goto Declaration" and "Project-Wide Auto Completion" can look within indices, within files by performing standard search, or be completely turned off.
Vote if you find it useful.