ExecEval (execute-keys / evaluation-commands)

Description

The execute-keys and evaluate-commands commands can be used to
run Kakoune commands:

execute-keys [<switches>] <key> ...
evaluate-commands [<switches>] <command> ...

execute-keys runs keys as if they were pressed, whereas
evaluate-commands evaluates its given parameters as if they were
entered in the command prompt. By default, their execution happens
within the context of the current client, and stops when the last
key/command is reached, or an error is raised.

execute-keys also save the following registers, who are then
restored when the commands have been executed: /, ", |,
^, @. evaluate-commands does not save any registers by
default. (See :doc registers)

Optional switches

-client <name>
execute in the context of the client named name

-try-client <name>
execute in the context of the client named name if such client
exists, or else in the current context

-draft
execute in a copy of the context of the selected client. Modifications
to the selections or input state will not affect the client. This
permits to make some modification to the buffer without modifying the
user’s selection

-itersel
execute once per selection, in a context with only the considered
selection. This permits avoiding cases where the selections may get
merged

-buffer <names>
execute in the context of each buffers in the comma separated list
names. * as a name can be used to iterate on all non-debug buffers
(See :doc buffers)

-save-regs <regs>
regs is a string of registers to be restored after execution (overwrites
the list of registers saved by default, c.f. description)

evaluate-commands specific switches

-no-hooks
disable hook execution while executing the keys/commands (See
:doc hooks)

execute-keys specific switches

-with-maps
use user key mapping in instead of built in keys (See
:doc mapping)

-with-hooks
the execution of keys will trigger existing hooks (See
:doc hooks)

Hi, @robertmeta! Could you please give me an example of using the -draft switch? Currently I don’t understand why it is useful. I mean, if it neither modify the buffer nor modify any register (since execute-keys restores the values of registers), it’s like it’s not been run at all. Certainly I’m missing something, so I’d be happy if you (or someone else in this community) could provide some examples showing me how it’s meant to be used.

1 Like

Given a word on a line selected, compare exec X and exec -draft X. The draft switch allow you for example to select something (here a line) and do whatever computation you want on this selection without touching your current selection(s) (and all val related).

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You can see a Kakoune session as an Etherpad, where each client (window) is a user having a view on your pad (buffer).

Moving their cursors does not have consequence on your selection, but if they add or remove content, you will see the result, and it might have consequence on what you had selected.

A draft context is a headless client. You can open a new client with :new and pretend it is a draft context. Try all sort of things (move your selections, commit changes, set an option (at the global, buffer and window scope) with the result of what you selected) and see what happens and what you can access in your original client.

Examples

Search -draft in GitHub repositories

Control flow

try %{
  evaluate-commands -draft %{
    ...
  }
  ...
}

Commit changes without changing the current mode

define-command surround-parenthesis %{
  execute-keys -draft i(
  execute-keys -draft a)
}

map global insert <a-)> '<a-;>: surround-parenthesis<ret>'

Build options (highlighters and completers)

4 Likes

I guess you mean

map global normal <a-)> '<a-;>: surround-parenthesis<ret>'

Right?

Thanks for the explanation. I mistakenly thought we couldn’t write to the buffer if we use the -draft switch and, as such, evaluate-commands and execute-keys wouldn’t produce any side effect.

Nope, insert not normal.

Random aside: this is exactly the type of conversations I hoped Manual++ would generate, thanks for kicking it off @gustavo-hms

:wink: