16.11 )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. frame names 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 frame new `` 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 frame next `` initial`` frame, use frame last

)frame next


)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. frame drop

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. file:history 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 )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 set message frame 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 set message prompt frame that looks like

initial (1) ->

prompt:with frame name when you start up. In this case, the frame name and step make up the prompt.

Also See: )history ugSysCmdhistory and )set ugSysCmdset.