[O] [babel-R][RFC] Customizing the R prompt for babel sessions approach, advice, discussion

[Grant Rettke]

Good evening,

The `R' programming language lets you set a custom prompt by evaluating

this `R' code:

╭────

│ options(prompt="ℝ> ")

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When you are using `ess' [1] you need to let it know that you are using

a different prompt than the defult by customizing the following value

like this:

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│ (defcustom inferior-S-prompt "[]a-zA-Z0-9.[]*\\(?:[>+.] \\)*ℝ+> "

│   "Regexp used in S and R inferior and transcript buffers for prompt navigation.

│ Customise it to make `comint-previous-prompt' quiqly navigate to

│ interesting portions of the buffer.

│  "

│   :group 'ess-proc

│   :type 'string)

╰────

In order for `babel' to work correctly with the custom prompt currently

I make a change manually to ob-R.el in the function

`org-babel-R-evaluate-session' to modify the regex to look like this:

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│ "^\\([ ]*[ℝ>+\\.][ ]?\\)+\\([[0-9]+\\|[ ]\\)"

╰────

Instead of making the change by hand I would like to add a new

customizable value to ob-R that contains the regex. The goal is to let

the user customize it themselves to accomodate any prompt. A couple of

weeks ago I posted a [patch] with that intent, and aaronecay provided

valuable feedback… but what I did wrong was both not discussing it with

anyone before I sent that patch and I also was too aggressive with the

change (it was a bad idea for the change).

Question:

• What do you think of such a change?

• Do you have a desired approach?

• Would you like a patch?

  • My change would be really basic, just add a new defcustom to store

    the regex and reference it in the session evalution function

It would change from this

╭────

│ (if (string-match

│      "^\\([ ]*[ℝ>+\\.][ ]?\\)+\\([[0-9]+\\|[ ]\\)" line)

│     (substring line (match-end 1))

│   line)

╰────

to this

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│ (if (string-match

│      inferior-R-prompt line)

│     (substring line (match-end 1))

│   line)

╰────

╭────

│ emacs-version

╰────

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│ 24.3.1

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╭────

│ org-version

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│ 8.2.7c

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╭────

│ ess-version

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╭────

│ 14.06

╰────

Kind regards,

[patch]

https://lists.gnu.org/archive/html/emacs-orgmode/2014-08/msg00753.html

Footnotes

─────────

[1] [http://ess.r-project.org/]

Grant Rettke | ACM, ASA, FSF

address@hidden | http://www.wisdomandwonder.com/

“Wisdom begins in wonder.” --Socrates

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