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Opening New Cells - Conflict Resolution

Xic keeps an internal database of all cells that have been used, by name. When a new file is opened for editing, it may contain definitions for cells with the same name as those already in memory. Xic provides several features for dealing with this situation when it arises.

The symbol table used to store cells can be changed. Creating and installing a new symbol table enables Xic to start with a fresh database, though the original database can be reinstalled at any time. There is no problem with cells of the same name existing in different symbol tables. The symbol tables are manipulated with the Symbol Tables panel from the Cell Menu. Symbol tables are useful for global context saving and switching, but since only one table can be installed at a time, it is generally not possible to access cells from different symbol tables simultaneously. Cells used in a hierarchy must exist in or be saved in the same symbol table.

When a file is being read from disk and a cell whose name conflicts with an existing cell in memory is encountered, a Merge Control pop-up will generally appear. This allows the user to choose whether or not to overwrite the physical and/or electrical part of the cell in memory. Press Apply to continue with the conversion. One must press Apply for each cell where there is a conflict, or press Apply to Rest to apply the present setting to the rest of the cells that clash. Dismissing the pop-up performs the same function as Apply to Rest. The pop-up is removed when all conversions are done.

If the NoAskOverwrite variable is set (with the !set command), or equivalently the Don't prompt for overwrite instructions button in the Setup page of the Import Control panel (from the Convert Menu) is active, no Merge Control pop-up will appear, and the default action will be used. The default action will also be used in non-graphics (server or batch) mode.

The default action can be specified by setting the NoOverwritePhys and/or the NoOverwriteElec variables, or equivalently by making a selection from the Default when new cells conflict menu in the Setup page of the Import Control panel. If no choice is made by any means, the default is to overwrite the cell in memory, both physical and electrical parts. The initial selections in the Merge Control pop-up will reflect the settings of the default action.


next up previous contents index
Next: Object Tests Up: The Open Button: Open Previous: Reading Input With the   Contents   Index
Stephen R. Whiteley 2017-03-22