Hello!

I have an org-mode spreadsheet, in which I calculate durations from timestamps
like "[2021-03-14 Sun 03:50]" for example. Recently I saw, that using org-sbe
(org source block execute) in combination with the :var header argument can be
used to run arbitrary code for calculating values to put as result of
spreadsheet formulas (on
https://home.fnal.gov/~neilsen/notebook/orgExamples/org-examples.html
<https://home.fnal.gov/~neilsen/notebook/orgExamples/org-examples.html>). So I
went trying it out. The following is some GNU Guile code for calculating time
differences in hours:

~~~~
#+NAME: allinone
#+begin_src scheme :noweb yes :var org-timestamp-1="[2021-01-01 Fri 00:00]", org-timestamp-2="[2021-01-01 Fri 01:00]" :results output drawer replace :exports none
(import (srfi srfi-19))

(define SECOND 1)
(define MINUTE (* 60 SECOND))
(define HOUR (* 60 MINUTE))

(define org-timestamp-format "[~Y-~m-~d ~a ~H:~M]")

(define duration->time-utc
  (λ (duration)
    (make-time time-utc
               (time-nanosecond duration)
               (time-second duration))))

(define org-timestamp->time-utc
  (λ (timestamp-string)
    (let ([parsed-date (string->date timestamp-string org-timestamp-format)])
          (date->time-utc parsed-date))))

(define org-time-duration
  (λ (org-timestamp-1 org-timestamp-2)
    (time-difference (org-timestamp->time-utc org-timestamp-2)
                     (org-timestamp->time-utc org-timestamp-1))))

(define duration->org-timestamp
  (λ (duration)
    (time-utc->date
     (duration->time-utc duration)
     ;; timezone offset, assume all with no offset
     0)))

(define duration->hours
  (λ (duration)
    (/ (time-second duration) HOUR)))

(number->string
 (duration->hours
  (org-time-duration org-timestamp-1
                     org-timestamp-2)))
#+end_src
~~~~

The source block is named "allinone", because I tried previously with :noweb yes
and referencing other code blocks to be included, but thought that perhaps
org-sbe does not deal well with :noweb yes, so I wanted to make sure to keep
everything in one source block.

The variables org-timestamp-1 and org-timestamp-2 are referenced at the bottom
of the code.

The code runs find in run-guile for example, when I replace the 2 variables with
the default values of the variables, given in the header argument :var, as you
can see in this transcript:

~~~~
GNU Guile 3.0.5
Copyright (C) 1995-2021 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)> (import (srfi srfi-19))

(define SECOND 1)
(define MINUTE (* 60 SECOND))
(define HOUR (* 60 MINUTE))

(define org-timestamp-format "[~Y-~m-~d ~a ~H:~M]")

(define duration->time-utc
  (λ (duration)
    (make-time time-utc
               (time-nanosecond duration)
               (time-second duration))))

(define org-timestamp->time-utc
  (λ (timestamp-string)
    (let ([parsed-date (string->date timestamp-string org-timestamp-format)])
          (date->time-utc parsed-date))))

(define org-time-duration
  (λ (org-timestamp-1 org-timestamp-2)
    (time-difference (org-timestamp->time-utc org-timestamp-2)
                     (org-timestamp->time-utc org-timestamp-1))))

(define duration->org-timestamp
  (λ (duration)
    (time-utc->date
     (duration->time-utc duration)
     ;; timezone offset, assume all with no offset
     0)))

(define duration->hours
  (λ (duration)
    (/ (time-second duration) HOUR)))
scheme@(guile-user)> (define org-timestamp-1 "[2021-01-01 Fri 00:00]")
scheme@(guile-user)> (define org-timestamp-2 "[2021-01-01 Fri 01:00]")
scheme@(guile-user)> (number->string
 (duration->hours
  (org-time-duration org-timestamp-1
                     org-timestamp-2)))
$2 = "1"
scheme@(guile-user)>
~~~~

This code assumes, that I have to convert to a string at the end, to make a good
return value for org-mode spreadsheets.

Then I have this table in my document:

~~~~
|   | timestamp 1            | timestamp 2            | result |
|---+------------------------+------------------------+--------|
| # | [2021-03-14 Sun 03:50] | [2021-03-14 Sun 03:55] |        |
| # | [2021-03-14 Sun 03:50] | [2021-03-14 Sun 03:50] | nil    |
| # | [2021-03-14 Sun 03:50] | [2021-03-14 Sun 03:50] |        |
#+TBLFM: $4='(org-sbe "allinone" (org-timestamp-1 $2) (org-timestamp-2 $3))
~~~~

The one nil is from one time, when I answered "no" to the question, whether I
want to run the associated source block:

~~~~
Evaluate this emacs-lisp code block on your system? (yes or no)
~~~~

What is weird is, that it asks about an emacs-lisp code block, while my block is
a scheme block, which is set to GNU Guile on my Emacs.

When I answer "yes" instead, I get an error pasted into my table, destroying its
structure:

~~~~
|   | timestamp 1            | timestamp 2            | result                                                  |
|---+------------------------+------------------------+---------------------------------------------------------|
| # | [2021-03-14 Sun 03:50] | [2021-03-14 Sun 03:55] | ice-9/boot-9.scm:1669:16: In procedure raise-exception: |
In procedure open-input-string: Wrong type argument in position 1: (#{2021-03-14}# Sun #{03:55}#)

Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
scheme@(guile-user) [1]> |
| # | [2021-03-14 Sun 03:50] | [2021-03-14 Sun 03:50] | nil    |
| # | [2021-03-14 Sun 03:50] | [2021-03-14 Sun 03:50] |        |
#+TBLFM: $4='(org-sbe "allinone" (org-timestamp-1 $2) (org-timestamp-2 $3))

~~~~

Knowing, that the code worked just fime in Geiser, I wonder what the problem is.
I also only get that output, when I set the header arg :results of the source
block to `output`. When I set :results to `value`, then I get simply no result
at all.

To check, whether the same version of GNU Guile is running in whatever org-sbe
runs as is running in Geiser, I replace the whole source block code with the
following:

~~~~
(version)
~~~~

And it fills in the following:

~~~~
|   | timestamp 1            | timestamp 2            | result  |
|---+------------------------+------------------------+---------|
| # | [2021-03-14 Sun 03:50] | [2021-03-14 Sun 03:55] | "3.0.5" |
| # | [2021-03-14 Sun 03:50] | [2021-03-14 Sun 03:50] | nil     |
| # | [2021-03-14 Sun 03:50] | [2021-03-14 Sun 03:50] |         |
#+TBLFM: $4='(org-sbe "allinone" (org-timestamp-1 $2) (org-timestamp-2 $3))
~~~~

I have put the minimal org file with my code on
https://notabug.org/ZelphirKaltstahl/guile-examples/raw/488b4a73c3fc4c505a95c904402cbaeeeddd330c/time/minimal.org
<https://notabug.org/ZelphirKaltstahl/guile-examples/raw/488b4a73c3fc4c505a95c904402cbaeeeddd330c/time/minimal.org>

How can I get my time calculating code working?

What am I doing wrong?

Best regards,
Zelphir

-- 
repositories: https://notabug.org/ZelphirKaltstahl