When giving input to Xic, single and double quotes can be used to ``hide'' characters, such as space characters, that Xic would otherwise interpret incorrectly. Xic will generally strip the outermost quotes before processing, so inner-level quotes will be retained (quote marks of different types nest). A quote mark which is preceded by a backslash will be treated as an ordinary character.
As an example, consider the Edit command. The command prompt expects one or two tokens. The first token is the name of a file to open. The second token, if given, is the name of the cell to edit if the first token names a multi-cell file such as a GDSII file. Suppose that the file is in a directory named ``Xic Files''. Without the quoting mechanism, there is an obvious problem. To edit the file, one enters, for example (each of these would work),
"Xic Files"/my_design.gds
"Xic Files/my_design.gds"
Xic" "Files/my_design.gds
The double quotes make each of these strings appear to Xic as a single word.
Xic contains a ``hypertext'' editing capability, which is active in electrical mode. This is necessary, for example, when setting device properties which reference other devices or nodes. The device names and node numbers are set by Xic, and change if the circuit is modified, thus property text could become invalid if it were static. Instead, internally, strings are stored as data structures which reference pure text as well as devices and nodes by internal reference. Thus, these hypertext strings are always valid.
One accesses a hypertext reference by clicking on the schematic while text input is being solicited in the prompt area. The returned data can be a node reference, a device branch reference, or a device name. The string, as currently defined, is inserted into the displayed text in the prompt area in color. Note that one can only delete the whole item with the Delete and Bsp keys, the hypertext references are treated as single items.
In text edit mode, the arrow keys move the cursor back and forth, Bsp deletes the character or hypertext reference to the left of the cursor and moves the cursor to the left, and Delete deletes the object at the cursor. Ctrl-U deletes the entire line. Ctrl-A and Ctrl-E move the cursor to the beginning or end of the line, respectively. The line will scroll to the left or right if longer that the available space, when the cursor hits the left and right boundaries. The Esc key exits edit mode, discarding the input. The Enter key exits edit mode, saving the input, which is the normal way to terminate input.
If a line of text that is longer than 256 characters is opened for editing on the prompt line, the Text Editor will appear, loaded with the text. The text will be saved as a ``long text'' item.
These features are described more fully in the description of the label command (4.11).