Nav plugin for Micro text editor

The nav plugin provides simple code navigation:

• jumping to a definition (tag) of the given identifier
• jumping to a result of a simple search (grep) for the given text

In particular, it efficiently utilizes the mouse for easy jumping via a mouse click on an identifier.

Prerequisites

You need the following programs installed:

• grep
• GNU Global aka gtags
• fzf

For tag jumping, you need GTAGS index files to be created beforehand. That is usually as easy as running gtags in the top directory of your project.

Commands

• tag command jumps to the definition of the given identifier. If there are multiple definitions found, it runs fzf to show a menu of definitions, so you can select which one to jump to.

  Example:

  > tag foo
  

• grep command searches for matches of the given regex pattern in all files in the current directory. It runs fzf to show a menu of results of the search. When you select a match from this menu, it jumps to the location of that match.

  Example:

  > grep foo.*bar
  

  You can pass additional flags to grep. E.g. for a case-insensitive search:

  > grep -i foo
  

Mouse and key bindings

• Ctrl-MouseRight click on an identifier will jump to its definition, just like with the tag command. If the click is not on a word, it will instead jump back to the location where we were before the last jump.

• Alt-MouseRight click on a word will search for occurrences of this word in all files in the current directory, just like with the grep command. If the click is not on a word, it will instead jump back to the location where we were before the last jump.

• F9 key press will jump back to the location where we were before the last jump.

You can re-bind these actions to some other mouse buttons or keys if you wish, by modifying the corresponding bindings in your bindings.json.

Known bugs

• If grep takes long and we exit fzf before grep completes, if we then manage to interrupt grep via Ctrl-C (within the time window between fzf exit and subsequent grep exit), then the entire Micro terminates, even if there are unsaved changes! (Actually this seems to be a known Micro's issue #2612)
• Various grep flags (e.g. -F, -P) aren't properly supported
• Patterns with various special characters (e.g. quotes, backslashes, parentheses, spaces) aren't properly supported
• ...

Patches are welcome.