Texas Instruments TI-89 Developer's Manual page 1161

Appendix A: System Routines — Variable Name Utilities
CheckSysFunc
TI-89 / TI-92 Plus
Differences: None
See Also: SymSysVar, CheckReservedName
Example: The VarOpen function uses CheckSysFunc to make sure that graph
functions are not added to the list of functions for the user to select from
since they can only be modified by the Y= editor or directly through the
Define command. The following code fragment is from VarOpen.
SYM_ENTRY *SymPtr;
HANDLE hOpenVar;
.
.
.
if (0 == CheckSysFunc( SymPtr->Name, NULL ))
if (!PopupAddText( hOpenVar, EOF, SymPtr->Name, 0 ))
/ * memory full error */
.
.
.
TI-89 / TI-92 Plus Developer Guide
(continued)
Not for Distribution
1119
Beta Version January 26, 2001