learning_emacs.md

path	title
/learnings/emacs	Learnings: Emacs

Table Of Contents

• Editing Javascript in emacs

Editing Javascript in emacs

Calc Mode

<<Emacs_Calculations_Calc>>

I like literate-calc-mode for most things, and in fact use it to keep track of monthly bills.

But sometimes I want to run quick calculations where getting the answer is more important than showing the work.

Calc mode to the rescue

Formulas can either be on a single line of between delimiters: blank lines or LaTeX math delimiters ($, $$), @ (TexInfo), and a few others.

note: the blank lines delimiters mean there needs to be a blank line above and below the expression

10 - 5

place your cursor into the formula and M-x calc-embedded-update-formula.

5

now inside a line: $$ 10 - 5 $$ $$ 5 $$

You can also create variables, with :=

$$ budget := 500 $$

This is a bit trickier. In the region you need to M-X calc-embedded, then M-x calc-embedded again to get out

Now you can use this variable in your update formula call, like so: $$ budget - 100 $$ which returns $$ 400 $$.

Now, what if I'm computing things but want to keep the initial formula? Use =>

$$ 500 - 400 => $$ results in $$ 500 - 400 => 100 $$. In fact, if I subtract 300 instead and run the calculations, Emacs updates the answer once I run M-x calc-update-formula