developer wants sizes computed by the calc functions to automatically account for gutters and padding.

[jumblerg]

the parent is responsible for layout via the alignment, padding, and gutter attributes. the gutter attribute in particular is implemented by adding a negative margin to the parent itself and applying padding between the middle and outer elements of its children to add space between them. when a calc function is used to set the width or height of a child, eg :sh (- (r 1 1) (* 4 10)), it will currently not produce the expected result unless it also adjusted to accommodate these implementation details via (- (* num-gutters gutter-size) gutter-size).