What is the difference between adjust-leading-to vs leader in Compass?

Question

I'm learning Compass, I'm a little bit confused about 2 mixins: adjust-leading-to and leader. Can some one tell me the difference between them?

Answer 1

adjust-leading-to adjusts the line-height within a text block

leader adds whitespace (margin or padding) before a text block.

see: http://compass-style.org/reference/compass/typography/vertical_rhythm/