Arc Forum | An unrelated question about the ':' syntax: does it really compose functions, or...

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1 point by PieSquared 5996 days ago | link | parent

An unrelated question about the ':' syntax: does it really compose functions, or does it work with macros as well?

In other words, can I say

  (macro:function arguments)

or does it only work with functions?

2 points by absz 5990 days ago | link

It's actually in-between:

  (f:g a b c)

becomes

  ((compose f g) a b c)

, which normally wouldn't work if f or g were a macro; however, compose is special-cased in ac.scm so that in the head of a list, this becomes

  (f (g a b c))

. Thus, : only works with macros at the head of a list. You can't do

  (f a b macro:function c)

.

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1 point by tokipin 5996 days ago | link

it works with macros as well, which makes for a convenient "modifier" syntax

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1 point by almkglor 5996 days ago | link

The "ultimate" modifier being p-m:

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