Does this list look familiar? How could there be so many code editors? If you are like me, every time you venture out to try a new editor the result is the same: the new editor has some great features and falls short in other ways. To this day I continue my search for the one editor to rule them all. The biggest issues that prevent editors from living up to my standards are (in no particular order):
The ideal editor needs to be able to absorb any and all of the awesome functionality found in other editors in a beginner-friendly, straight forward, modular way. This means a few things:
The settings also need to be set as optimally as possible right from the get-go. A good way to accomplish this is to accept anonymous user feedback on how their settings are - paying attention to how the default settings have been changed and evolving the default settings over time based on popularity and use cases.
Some things I have never seen done before that I would really like to see:
The editor must be as straight forward as notepad.exe. The fancy underlying functionality must not get in the way of the bare minimum basics. Ever. Anything extra should be added on top, not the other way around.
One of the biggest issues by far with almost all editors is their spectacular inability to deal with indentation. Autodetection must work as flawlessly as possible. Files with mixed tabs and spaces should prompt the user when opened for normalization when appropriate. Formatting entire projects should be a snap. Making it easy peasy to use community coding standards would encourage users to write cleaner code.
In a similar manner to indentation, code formatting functionality should be thorough and work mostly automatically. The user needs to be able to customize the code formatting in any way. Previously used code formatting settings should be available via save/load. Standard coding formats should be at the user's fingertips. When standard coding formats are used, format should run each time the user saves.
As the code is created, the editor should try to help the user as much as possible but still get out of the user's way when he or she wants something specific. For example, after a user types something exactly as they want it and makes a newline, often editors will auto-format the code on the previous line. This is fine, but the ideal editor should include the formatting as an additional undo option. When the user does so, the editor should prompt the user in a non-obtrusive way to redefine the existing standard to match the previous line. When possible, the redefinition should be performed automatically without the need for the user to do so manually. If inconsistencies are found, only the inconsistencies should prompt the user further.
A setting should exist making it possible for the user to have their code formatted whenever it is saved.
Interacting with code as it is written is essential. This means a number of things. Ideally there would (optionally) be a connection to the programming language itself. This may require some setup. Streamlining the setup for the user is important.
Web programming should integrate directly with a browser. Front end code should update as it is written and back end code on save. Automation techniques similar to macros or selenium take this from somewhat annoying to can't live without. Hooks need to be available for key events and file save events for the user to decide based on how heavy the page load is, etc.
Turning language awareness up or down while programming should be a snap. Sometimes a programmer just wants to hack and doesn't need constant reminders that the code isn't working yet.
The less programmers have to move their hands, the healthier their hands are, and the more effective they are at working. To this end chording should be introduced as a core concept very early on.
Whenever someone creates new functionality to share with the rest of the community, it would help everyone if a working interactive tutorial shipped with it. This should be built into the framework from the very beginning rendering the help section actually helpful.
This is just a short list. Quite a bit of this is somewhat esoteric and won't be used by everyone. There are lots of things that other people want out of their editors which aren't listed here. The whole point is: editors should do what users want.