utop command in emacs

[newsomc]

Thank you for providing Emacs support! But I'm not sure I understand the instructions...what do you mean by executing "utop" in emacs? Do you mean M-x utop? If so that doesn't seem to work for me.

I installed utop via opam like this:

$ opam init $ opam switch 4.00.1+short-types $ opam install utop core_extended $ eval `opam config -env`

I have an .omalinit that looks like this:

# use "topfind" # camlp4o # thread # require "core.top"

When I run M-x utop I get

Cannot open load file: utop

Thanks for your help,

C

[ghost]

Do you mean M-x utop?

Yes.

opam install utop will install utop.el into the opam prefix, so by default the file will be ~/.opam/system/share/emacs/site-lisp/utop.el. You need to ensure that this path is your emacs load path. You can add this to your .emacs:

(push "~/.opam/system/share/emacs/site-lisp" load-path)

In your case replace system by 4.00.1+short-types. I'll add a note about this in the readme.

[ghost]

And to dynamically find the right location:

(let ((opam-prefix
       (replace-regexp-in-string
        "[ \r\n\t]*$" ""
        (with-output-to-string
          (with-current-buffer
              standard-output
            (call-process "opam" nil t nil "config" "var" "prefix"))))))
  (push (concat opam-prefix "/share/emacs/site-lisp") load-path))

[newsomc]

Thanks a bunch for your help with this. I'm not quite there yet. This is my current Ocaml config for emacs:

(push "~/.opam/4.00.1+short-types/share/emacs/site-lisp/" load-path)
(let ((opam-prefix
       (replace-regexp-in-string
        "[ \r\n\t]*$" ""
        (with-output-to-string
          (with-current-buffer
              standard-output
            (call-process "opam" nil t nil "config" "var" "prefix"))))))
  (push (concat opam-prefix "/share/emacs/site-lisp") load-path))
(autoload 'utop "utop" "Toplevel for OCaml" t)
(autoload 'utop-setup-ocaml-buffer "utop" "Toplevel for OCaml" t)

The error I get when attempting to eval the let statement is this:

Debugger entered--Lisp error: (file-error "Searching for program" "No such file or directory" "opam") call-process("opam" nil t nil "config" "var" "prefix") (save-current-buffer (set-buffer standard-output) (call-process "opam" nil t nil "config" "var" "prefix")) (with-current-buffer standard-output (call-process "opam" nil t nil "config" "var" "prefix")) (let ((standard-output standard-output)) (with-current-buffer standard-output (call-process "opam" nil t nil "config" "var" "prefix"))) (progn (let ((standard-output standard-output)) (with-current-buffer standard-output (call-process "opam" nil t nil "config" "var" "prefix"))) (with-current-buffer standard-output (buffer-string))) (unwind-protect (progn (let ((standard-output standard-output)) (with-current-buffer standard-output (call-process "opam" nil t nil "config" "var" "prefix"))) (with-current-buffer standard-output (buffer-string))) (kill-buffer standard-output)) (let ((standard-output (get-buffer-create (generate-new-buffer-name " _string-output_")))) (unwind-protect (progn (let ((standard-output standard-output)) (with-current-buffer standard-output (call-process "opam" nil t nil "config" "var" "prefix"))) (with-current-buffer standard-output (buffer-string))) (kill-buffer standard-output))) (with-output-to-string (with-current-buffer standard-output (call-process "opam" nil t nil "config" "var" "prefix"))) (replace-regexp-in-string "[ \n ]_$" "" (with-output-to-string (with-current-buffer standard-output (call-process "opam" nil t nil "config" "var" "prefix")))) (let ((opam-prefix (replace-regexp-in-string "[ \n ]_$" "" (with-output-to-string (with-current-buffer standard-output (call-process "opam" nil t nil "config" "var" "prefix")))))) (push (concat opam-prefix "/share/emacs/site-lisp") load-path)) eval((let ((opam-prefix (replace-regexp-in-string "[ \n ]*$" "" (with-output-to-string (with-current-buffer standard-output (call-process "opam" nil t nil "config" "var" "prefix")))))) (push (concat opam-prefix "/share/emacs/site-lisp") load-path)) nil) eval-last-sexp-1(nil) eval-last-sexp(nil) call-interactively(eval-last-sexp nil nil)

[ghost]

Note that you only need one of the two expressions. The second one is if you are using several prefixes and want to automatically find the right one. Regarding the error it seems that "opam" is not in your PATH.

[f6m6]

I'm in basically the same situation - did this get resolved? opam is in my PATH I think as when I run opam from a terminal it works

[newsomc]

I wasn't able to resolve.

On Jun 7, 2013, at 9:37 AM, Farhan Mannan notifications@github.com wrote:

I'm in basically the same situation - did this get resolved? opam is in my PATH I think as when I run opam from a terminal it works

—
Reply to this email directly or view it on GitHub.

[ghost]

Unfortunately there is nothing that can be done in utop. You have to add this line in your ~/.emacs:

(push "~/.opam/system/share/emacs/site-lisp" load-path)

utop installs the utop.el file into the prefix specified at configuration time.

[f6m6]

I already have that (well actually I have (push "~/.opam/4.01.0dev+trunk/share/emacs/site-lisp" load-path)) but I am getting the same error. Oh well

[ghost]

Can you check that utop.el is indeed present in this directory? If yes then this is probably an emacs problem not related to utop. You cal also try to load the file by hand with M-x load-file to see if it works.

[newsomc]

What version of emacs are you using Jeremie? On what OS?

On Jun 24, 2013, at 1:34 AM, Jérémie Dimino notifications@github.com wrote:

Can you check that utop.el is indeed present in this directory? If yes then this is probably an emacs problem not related to utop. You cal also try to load the file by hand with M-x load-file to see if it works.

—
Reply to this email directly or view it on GitHub.

[ghost]

I am using different ones:

• on my old linux laptop: debian + emacs 24
• on my MacBook: OS X Mountain Lion + emacs 24

[samebchase]

I'm having similar problems too. I have been manually able to M-x load-file utop.el.

I was not able to run utop in zsh until OPAM added this line to my .zshrc

. /home/samuel/.opam/opam-init/init.zsh > /dev/null 2> /dev/null || true

It seems that script modifies the environment variables necessary for utop to be run.

Attempting to run utop in say M-x eshell gives me the error:
Searching for program: no such file or directory, utop

I think the problem is that the path to utop isn't in the $PATH in the shell emacs uses. How do I do the equivalent of the .zshrc configuration as pasted above, but for the shell emacs uses.

[ghost]

With a recent opam version you can add in your ~/.emacs:

(dolist (var (car (read-from-string (shell-command-to-string "opam config env --sexp"))))
  (setenv (car var) (cadr var)))

[samebchase]

Hello @diml, thanks for the suggestion,

The relevant lines in my .emacs are as follows:

(add-to-list 'load-path "/home/samuel/.opam/4.01.0dev+trunk/share/emacs/site-lisp/")
(autoload 'utop "utop" "Toplevel for OCaml" t)
(autoload 'utop-setup-ocaml-buffer "utop" "Toplevel for OCaml" t)

(dolist (var (car (read-from-string (shell-command-to-string "opam config env --sexp"))))
  (setenv (car var) (cadr var)))

Does that look right?

The utop command runs in eshell now, but as usual, doing an M-x utop gives me the error: Searching for program: no such file or directory.

[ghost]

Does that look right?

Yes.

The utop command runs in eshell now, but as usual, doing an M-x utop gives me the error: Searching for program: no such file or directory.

Ah yes, that's because emacs parses PATH only once at startup. You can try to add this at the end:

(setq exec-path (split-string (getenv "PATH") path-separator))

[samebchase]

Yay. It works now. Thanks a lot @diml. :-)

I'll paste the following as a minimal utop configuration for .emacs that others may find useful:

(add-to-list 'load-path "/home/samuel/.opam/4.01.0dev+trunk/share/emacs/site-lisp/")
(autoload 'utop "utop" "Toplevel for OCaml" t)
(autoload 'utop-setup-ocaml-buffer "utop" "Toplevel for OCaml" t)

(dolist (var (car (read-from-string (shell-command-to-string "opam config env --sexp"))))
  (setenv (car var) (cadr var)))

(setq exec-path (split-string (getenv "PATH") path-separator))

[ghost]

With the new intrusctions in the README it should now be easier to make utop work with emacs: https://github.com/diml/utop#integration-with-emacs