Call an evil-delete > evil-motion operation from elisp?

Question

I want to execute evil-delete and then call a motion command. A simple example which does not work because evil waits for input after calling evil-delete:

(defun does-not-work ()
  (call-interactively 'evil-delete)
  (call-interactively 'end-of-line))

EDIT:

The command after evil-delete is just in example. The real code I want to call expects additional input from the user.

Answer 1

First of all, if your goal is to translate something from a .vimrc, it's as simple as (define-key evil-normal-state-map (kbd ...) "d$"). If you want to write new commands to use from Evil, it's better to construct these from Emacs primitives and wrap them as needed with Evil macros. But if you're just interested in how Evil works, then read on...

As you've noticed already, if you're calling an operator like evil-delete interactively, it will read in its arguments as specified by its interactive spec. Reading evil-commands.el reveals that evil-delete is defined with the evil-define-operator macro which turns the rather unusual looking "<R><x><y>" spec into something Emacs can deal with, a list evaluating to the desired values!

evil-types.el has a listing of these codes. <x> is evil-this-register, <y> is (evil-yank-handler). Since you haven't expressed interest in any of those (and the usage of evil-delete as displayed by F1 f evil-delete suggests they are optional anyways), let's take a closer look at <R> which is using (evil-operator-range t) to evaluate to a list looking like (BEG END TYPE). evil-operator-range reads in a motion, checks up on its properties (like, its type), then executes it to determine where the motion did begin and where it does end. A motion in Evil is just an Emacs command taking point somewhere else after all...

So, considering our type isn't line or block and evil-delete doesn't care what other value it is, we'll go with t for TYPE. BEG is going to be (point) because we're deleting from where we are at, END is set with (move-end-of-line COUNT) in evil-end-of-line and can be determined by wrapping it into save-excursion:

(evil-delete (point) (save-excursion (move-end-of-line 1) (point)) t)

This can probably be simplified to:

(evil-delete (point) (line-end-position) t)

Or if you don't need to do this with Evil (because you're writing a new command and don't actually need to repurpose it):

(delete-region (point) (line-end-position))