Cannot use the result of modular scale as a negative measure

[wc-matteo]

Input

margin: 0 -ms(1)rem;

Output

margin: 0 1rem;

Expected

margin: 0 -1rem;

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Even worse:

Input

margin: 0 -ms(1)rem -ms(1)rem;

Output

margin: 0 -ms(1;

Expected

margin: 0 -1rem -1rem;

[kristoferjoseph]

these are two issues in one.

1. ms currently does not support short hand ( on purpose ) but I have been considering adding support because this issue gets filed a bit.
2. there is not a way to negate a scale step currently. A work around would be to add the step you want as a negative value in the scale itself. ms is naive in that it solely looks up a scale value and appends the unit to it. adding a - to the beginning of a function name is actually renaming the function to call. margin: -ms(1)rem is equivalent to saying margin: hamsandwich-ms(1)rem

[wc-matteo]

Thank you for your answer.

A work around would be to add the step you want as a negative value in the scale itself.

And how would I do that? Currently, I'm binding the scale to some CSS vars (i.e. --ms1, --ms2, etc.).

I don't get the 'rename function to call with -' bit...

First, is it so according to the CSS spec or PostCSS? And second, are you saying that the character - and every character before it is effectively ignored from the parser when determining a function name? If so, what's the point?

Anyway, the PostcSS processor for var() supports the minus in front of it just fine.

I think this issue is an important one to solve; consequently, it should stay open.

Just as an example: when using columns with padding and box-sizing: border-box, you'll usually want to apply a negative margin equal to column padding to the container.

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As an aside, I read that you were against a default unit for ms(). I found that rem is the default though; what made you change your mind?