Vim: Goto File

Vim has an awesome feature that I think is not shown off enough. It’s pretty easy to use and configure, but thankfully many languages have a sensible configuration out of the box.

Vim has this feature that opens a file when you press gf over a filename. On the face of it, it’s only sort of useful. There are a couple settings that make this feature incredibly handy.

First and foremost, you have to set your path. Typically when you open a Perl script or module in vim, the path is set to something like this:

$(pwd)

/usr/include

$PERL5LIB

And Perl’s default @INC

It’s a good idea to add the path of your current project, for example:

:set path+=lib

So on a typical Linux system, you can type out zlib.h and press gf over it and pull up the zlib headers. The next feature is what really makes it powerful.

🔗 suffixesadd and includeexpr

The more basic of the two options is suffixesadd. It is simply a list of suffixes to attempt to add to the filename. So in the example above, if you :set suffixesadd=.h and then type zlib and then press gf on the word, you’ll pull of the header files for zlib. That’s too basic for most modern programming environments though. Here’s the default includeexpr for me when I open a perl script:

substitute(substitute(substitute(v:fname,'::','/','g'),'->*','',''),'$','.pm','')

Let’s unpack that to make sure we see what’s going on. This may be subtly incorrect syntax, but that’s fine. The point is to communicate what is happening above.

to_open = v:fname # replace all :: with / to_open = substitute(to_open,'::','/','g') # remove any method call (like ->foo) to_open = substitute(to_open,'->*','','') # append a .pm to_open = substitute(to_open,'$','.pm','')

With the above we can find the filename to open. This is the default. You can do even better, if you put in a little effort. Here is an idea I’d like to try when I get some time, call a function as the expression, and in the function, if the fname contains, ->resultset(...) return the namespaced resultset. I’d need to tweak the ifsname to allow selecting weird characters, and maybe that would be more problematic than it’s worth, but it’s hard to know before you try. Could be really handy!

Even if you don’t go further with this idea, consider using gf more often. I personally use it (plus CTRL-O as a “back” command”) to browse repos and even the Perl modules they depend on.

(The following includes affiliate links.)

If you’d like to learn more, I can recommend two excellent books. I first learned how to use vi from Learning the vi and Vim Editors . The new edition has a lot more information and spends more time on Vim specific features. It was helpful for me at the time, and the fundamental model of vi is still well supported in Vim and this book explores that well.

Second, if you really want to up your editing game, check out Practical Vim . It’s a very approachable book that unpacks some of the lesser used features in ways that will be clearly and immediately useful. I periodically review this book because it’s such a treasure trove of clear hints and tips.

Posted Tue, Jun 21, 2016

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