====================================================================
A.11.  )frame
====================================================================
 
User Level Required:  interpreter
 
Command Syntax: 
 
  - )frame  new  frameName
  - )frame  drop  [frameName]
  - )frame  next
  - )frame  last
  - )frame  names
  - )frame  import frameName [objectName1 [objectName2 ...]]
  - )set message frame on | off
  - )set message prompt frame
 
Command Description: 
 
A frame can be thought of as a logical session within the physical session
that you get when you start the system. You can have as many frames as you
want, within the limits of your computer's storage, paging space, and so on.
Each frame has its own step number, environment and history. You can have a
variable named a in one frame and it will have nothing to do with anything
that might be called a in any other frame.
 
Some frames are created by the HyperDoc program and these can have pretty
strange names, since they are generated automatically. To find out the names
of all frames, issue
 
)frame names
 
It will indicate the name of the current frame.
 
You create a new frame ``quark'' by issuing
 
)frame new quark
 
The history facility can be turned on by issuing either )set history on or
)history )on. If the history facility is on and you are saving history
information in a file rather than in the FriCAS environment then a history
file with filename quark.axh will be created as you enter commands. If you
wish to go back to what you were doing in the ``initial'' frame, use
 
)frame next
 
or
 
)frame last
 
to cycle through the ring of available frames to get back to ``initial''.
 
If you want to throw away a frame (say ``quark''), issue
 
)frame drop quark
 
If you omit the name, the current frame is dropped.
 
If you do use frames with the history facility on and writing to a file, you
may want to delete some of the older history files. These are directories, so
you may want to issue a command like rm -r quark.axh to the operating system.
 
You can bring things from another frame by using )frame import. For example,
to bring the f and g from the frame ``quark'' to the current frame, issue
 
)frame import quark f g
 
If you want everything from the frame ``quark'', issue
 
)frame import quark
 
You will be asked to verify that you really want everything.
 
There are two )set flags to make it easier to tell where you are.
 
)set message frame on | off
 
will print more messages about frames when it is set on. By default, it is
off.
 
)set message prompt frame
 
will give a prompt that looks like
 
initial (1) ->
 
when you start up. In this case, the frame name and step make up the prompt.
 
Also See: 
o )history
o )set
 
