Calculations à la Emacs Rocks -- with `multiple-cursors`

Question

In this "Emacs Rocks" video relating to the library multiple-cursors ( https://github.com/magnars/multiple-cursors.el ), the author demonstrates a way of swiftly performing calculations, getting the result in the main window (not in the mini buffer). However, he does not explain what commands are being used. I haven't been able to replicate them, having consulted the available documentation.

Any ideas on how he does it?

He does explain what commands are being used, by the way: just look at the list under the embedded video. — Constantine, Nov 19 '14 at 01:54

score 6 · Answer 1 · answered Nov 19 '14 at 01:53

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The same Emacs Rocks page links to an implementation of eval-and-replace used to replace a sexp with its value in this episode.

answered Nov 19 '14 at 01:53

Constantine

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score 5 · Accepted Answer · answered Nov 19 '14 at 01:54

5

The idea is to evaluate some Elisp inline and replace it with the result. It looks like he did it with a custom function he defined and bound to C-x C-e.

Note that C-x C-e is bound to eval-last-sexp by default, which does something very similar. It evaluates the s-expression just before your cursor. If you call it with a prefix argument, it will paste the result into the current buffer, but it won't delete the expression. So play around with it:

(* 100 200)

Put your cursor at the end of that and do C-u C-x C-e to get:

(* 100 200)20000

answered Nov 19 '14 at 01:54

Tikhon Jelvis

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Great. Thanks for the answer and explanation. – NVaughan Nov 19 '14 at 02:05
The latest version of smex causes some trouble invoking this function for all cursors, but it works fine when you bind it to a key chord. – Lenar Hoyt Nov 25 '14 at 18:09

Calculations à la Emacs Rocks -- with `multiple-cursors`

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