set-before

Changes the depth of a snip. See Basic Organization for information about snip order in pasteboards.

See also raise, lower, and set-after.

• (send a-pasteboard set-before snip before) -> void
      snip : snip% object
      before : snip% object or #f

  Changes the depth of snip moving it just in front of before. If before is #f, snip is moved to the front.