#### 7.2.59 hdefine

`(hdefine geometry|camera|window|appearance|image|transform|ntransform name value)`
  Sets the value of a handle of a given type.

                  (hdefine  <type>  <name>  <value>)

  is generally equivalent to

                  (read <type>  { define <name> <value> })

  except that the assignment is done when hdefine is executed, (possibly not at all if inside a conditional statement), while the `read ... define` performs assignment as soon as the text is read. See References. See `(read ...)`. See `(hdelete ...)`.