Re: execute incomplete commands when theres only one completion

[Nathan Shostek]

I'm unsure how useful this would be to the community. It seems (to me)
to be pretty hacky, and there are a couple edge cases where it doesnt
behave properly with regards to inserting a hyphen or a space

David Bjergaard writes:

> If the community would benefit feel free to open a pull request and we’ll get 
> the code reviewed and integrated in stumpwm proper. 
>
>     David
>
>> On Feb 27, 2020, at 4:53 PM, Nathan Shostek <address@hidden> wrote:
>> 
>> Sorry for spamming this mailing list, but I've worked out how to achieve
>> the emacs-esq completions I would like to have when inputing commands
>> via colon. Knowing myself, I'm probably doing something wrong, but it
>> seems to work fine.
>> 
>> Heres the code: https://gist.github.com/szos/d7dbd8f1c9f4b7d71666bafe8621629c
>> 
>> Cheers,
>> Nathan
>> 
>> Nathan Shostek writes:
>> 
>>> After digging further, I think the best place to make changes isnt inthese
>>> functions, but rather in get-completion-preview-list. Does this sound 
>>> correct?
>>> 
>>> Thanks,
>>> Nathan s
>>> 
>>> Responding to: 
>>> 
>>>> Hello,
>>>> 
>>>> When Emacs is accepting input via M-x one can forego writing the whole 
>>>> command
>>>> due to the way emacs completes it. While I'm not skilled enough to 
>>>> implement
>>>> emacs style completion, I do think it would be nice to be able to complete
>>>> incomplete commands when there is only one possible completion. I'm 
>>>> putting this
>>>> here instead of in a github pull request because, in all truthfulness, 
>>>> github
>>>> forking and pull-requesting confuses me, and someone told me I could also 
>>>> submit my contributions throught this mailing list. 
>>>> 
>>>> I've modified the functions eval-command and call-interactively to have an 
>>>> additional optional argument called auto-complete, which when true retries
>>>> completion before throwing an error. I'm not sure if this is the right way
>>>> to get the behavior I want, but it works. If theres a better way to do this
>>>> I'll gladly try to implement it. 
>>>> 
>>>> Apologies for the length of this email; I figured it was better to include 
>>>> every
>>>> function than just the small bits i changed, but if its not let me know 
>>>> and I'll
>>>> do it differently in the future.
>>>> 
>>>> Cheers,
>>>> Nathan
>>>> 
>>>> Heres the code:
>>>> 
>>>> (defun call-interactively (command &optional (input "") auto-complete)
>>>>  "Parse the command's arguments from input given the command's
>>>> argument specifications then execute it. Returns a string or nil if
>>>> user aborted."
>>>>  (declare (type (or string symbol) command)
>>>>           (type (or string argument-line) input))
>>>>  ;; Catch parse errors
>>>>  (catch 'error
>>>>    (let* ((arg-line (if (stringp input)
>>>>                         (make-argument-line :string input
>>>>                                             :start 0)
>>>>                         input))
>>>>           (cmd-data (or (get-command-structure command)
>>>>             (and auto-complete
>>>>                  (let ((comp (input-find-completions command 
>>>> (all-commands))))
>>>>                (when (and comp (= 1 (length comp)))
>>>>                  (get-command-structure (car comp)))))
>>>>             (throw 'error (format nil "Command '~a' not found." command))))
>>>>           (arg-specs (command-args cmd-data))
>>>>           (args (loop for spec in arg-specs
>>>>               collect (let* ((type (if (listp spec)
>>>>                        (first spec)
>>>>                        spec))
>>>>                      (prompt (when (listp spec)
>>>>                        (second spec)))
>>>>                      (fn (gethash type *command-type-hash*)))
>>>>                 (unless fn
>>>>                   (throw 'error (format nil "Bad argument type: ~s" type)))
>>>>                 ;; If the prompt is NIL then it's
>>>>                 ;; considered an optional argument and
>>>>                 ;; we shouldn't prompt for it if the
>>>>                 ;; arg line is empty.
>>>>                 (if (and (null prompt)
>>>>                      (argument-line-end-p arg-line))
>>>>                     (loop-finish)
>>>>                     (funcall fn arg-line prompt))))))
>>>>      ;; Did the whole string get parsed?
>>>>      (unless (or (argument-line-end-p arg-line)
>>>>                  (position-if 'alphanumericp (argument-line-string 
>>>> arg-line) :start (argument-line-start arg-line)))
>>>>        (throw 'error (format nil "Trailing garbage: ~{~A~^ ~}" (subseq 
>>>> (argument-line-string arg-line)
>>>>                                                                        
>>>> (argument-line-start arg-line)))))
>>>>      ;; Success
>>>>      (prog1
>>>>          (apply (command-name cmd-data) args)
>>>>        (setf *last-command* command)))))
>>>> 
>>>> (defun eval-command (cmd &optional interactivep auto-complete)
>>>>  "exec cmd and echo the result."
>>>>  (labels ((parse-and-run-command (input)
>>>>             (let* ((arg-line (make-argument-line :string input
>>>>                                                  :start 0))
>>>>                    (cmd (argument-pop arg-line)))
>>>>               (let ((*interactivep* interactivep))
>>>>                 (call-interactively cmd arg-line auto-complete)))))
>>>>    (multiple-value-bind (result error-p)
>>>>        ;; this fancy footwork lets us grab the backtrace from where the
>>>>        ;; error actually happened.
>>>>        (restart-case
>>>>            (handler-bind
>>>>                ((error (lambda (c)
>>>>              (invoke-restart 'eval-command-error
>>>>                      (format nil "^B^1*Error In Command '^b~a^B': ^n~A~a"
>>>>                          cmd c (if *show-command-backtrace*
>>>>                                (backtrace-string) ""))))))
>>>>              (parse-and-run-command cmd))
>>>>          (eval-command-error (err-text)
>>>>            :interactive (lambda () nil)
>>>>            (values err-text t)))
>>>>      ;; interactive commands update the modeline
>>>>      (update-all-mode-lines)
>>>>      (cond ((stringp result)
>>>>             (if error-p
>>>>                 (message-no-timeout "~a" result)
>>>>                 (message "~a" result)))
>>>>            ((eq result :abort)
>>>>             (unless *suppress-abort-messages*
>>>>               (message "Abort.")))))))
>>>> 
>>>> (defcommand colon (&optional initial-input) (:rest)
>>>>  "Read a command from the user. @var{initial-text} is optional. When
>>>> supplied, the text will appear in the prompt.
>>>> 
>>>> String arguments with spaces may be passed to the command by
>>>> delimiting them with double quotes. A backslash can be used to escape
>>>> double quotes or backslashes inside the string. This does not apply to
>>>> commands taking :REST or :SHELL type arguments."
>>>>  (let ((cmd (completing-read (current-screen) ": " (all-commands) 
>>>> :initial-input (or initial-input ""))))
>>>>    (unless cmd
>>>>      (throw 'error :abort))
>>>>    (when (plusp (length cmd))
>>>>      (eval-command cmd t t))))
>> 
>>