Units

In the optional units clause, we can define units to use in relative calculations. The alias variables also works the same way. The four predefined ones are U, u, cx, and cy.

U: 19.05 # 19.05mm MX spacingu: 19 # 19mm MX spacingcx: 18 # 18mm Choc X spacingcy: 17 # 17mm Choc Y spacing

But we can add any other (or modify these predefined ones), or even use an existing measure in calculating a new value (for example, double: 2 u). Recall how each string that can be interpreted as a math formula will be treated like a number, so this is a great way to add math-level variables to your config.

units:  a: cy - 7  b: a * 1.5

In fact, there are also a few internal variables that rely on previous units and formulas to provide easily overrideable default values to certain key-level attributes (for further explanation, see the points section):

$default_stagger: 0,$default_spread: 'u',$default_splay: 0,$default_height: 'u-1',$default_width: 'u-1',$default_padding: 'u',$default_autobind: 10