draw_rect = macro # parameter name with default value: x ?= ... * empty right hand side evaluates to undefined * parameter order is order of declaration dep ?= x0 ?= 50.0 # hidden temporaries are prefixed with `_`, otherwise public _x0 = ftos x0 4 y0 ?= 50.0 _y0 = ftos y0 4 x1 ?= 100.0 _x1 = ftos x1 4 y1 ?= 100.0 _y1 = ftos y1 4 dep -> do draw_line _x0 _y0 _x1 _y0 draw_line _x1 _y0 _x1 _y1 draw_line _x1 _y1 _x0 _y1 draw_line _x0 _y1 _x0 _y0 # if a `return` name is present, the callsite evaluates to this value return = dep