Functions

Imported functions are not resolved yet

@-from parses and is preserved, but there is no module resolver in the 2.x alpha, so an imported function is never loaded or called. A call like double(10px) is passed through to the output verbatim. The syntax below is current; the behavior is the target.

Jess's built-in functions (mix, hsl, luma, …) do work today — and they resolve by name, without an import.

You import functions and call them like any other function:

@-from './functions.js' import (double);

.box {
  width: double(10px);
}

Like Less, Jess will attempt to evaluate a CSS-shaped function call as a JS function call when that name was imported in scope. The reason you might want that is to have the function receive and return typed values — for example a dimension, so units are preserved:

.box {
  width: 20px;
}

note

The $myFunction() spelling is a different thing: it calls a function that was defined in a stylesheet and bound to a variable, which is a value, not an imported name. See stylesheet-defined functions. Call imported functions by their bare name, as above.