Add interface to -g option about ag.el

[Wilfred]

Yep, I'd definitely see exposing ag -g as a worthwhile feature.

Perhaps we could add commands ag-find and ag-find-regexp? You might want ag-project-find too, to save prompting for the base directory.

find-dired is very cool, I've not seen it before, and the UI looks suitable for ag -g too.

Anyway, I'd welcome patches.

[Fuco1]

I've checked and ag doesn't support non-regexp argument for -g option yet, and I would not dare to escape the string manually in elisp to "not be regexp" myself since that's very easily breakable. So for now we'll only get ag-find-regexp. The project thing is also a good idea, I'll add that too.

I have it basically done, only adding docstrings and formatting it a bit better.

[Fuco1]

Hm, what about calling it ag-dired in analogy with find-dired (which can be interpreted as "run X and dump the output in dired")

[Wilfred]

It's actually pretty easy to escape PCRE regexes. I've found the implementation in the Python standard library:

_alphanum = frozenset(
    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")

def escape(pattern):
    "Escape all non-alphanumeric characters in pattern."
    s = list(pattern)
    alphanum = _alphanum
    for i, c in enumerate(pattern):
        if c not in alphanum:
            if c == "\000":
                s[i] = "\\000"
            else:
                s[i] = "\\" + c
    return pattern[:0].join(s)

[Fuco1]

Oh well that's pretty simple. I don't have time to continue hacking today, I can add this tomorrow to the same branch, then you can pull it all together.

[Wilfred]

Merged, so we're done here :).