Texas Instruments TI89 Developer Guide - Page 184

142 Chapter 13: Memory Management 13.3.2.6. For TEXT_VAR_TAG, GDB_VAR_TAG, PIC_VAR_TAG, DATA_VAR_TAG, or GEN_DATA_TAG the source is not copied but the destination is verified to have the same data type (TEXT, GDB, PIC, DATA, or OTH). If SourceSize is not zero then the destination is allocated to the given size; it is up to the caller to do the actual copying of data. VarStore may throw the following errors: ER_DATATYPE, ER_DOMAIN ER_DIMENSION ER_FOLDER ER_ILLEGAL_IN_FUNC ER_INVALID_VAR_REF ER_LOCKED, ER_VAR_IN_USE ER_MEMORY ER_PROTECTED ER_RESERVED INVALID_PATHNAME_ERROR - The value stored is in the wrong domain or of the wrong type for the variable being stored to. - Illegal index when storing to a list or matrix. - The variable is a folder, which cannot be stored to. - Functions can only store to local variables. - The variable cannot be stored to in the current mode, see VarRecall also. - The variable is locked or in-use and cannot be stored to. - Not enough memory to do the store operation. - The variable cannot be stored to by the current app in the current mode. - The given variable is a system reserved variable and the value to be stored is invalid for this variable. - Invalid variable name. General Data Storage Most of the data that will be stored in a variable will be on the estack or in a buffer in the heap. To store floating-point data contained in a C variable, use push_Float (var) and use top_estack as the EStackIndex for VarStore. This automatically rounds the mantissa to 14 digits and adds the float tag. The caller must remember to restore top_estack to its original value. Example: BCD16 flt; const BYTE Name[] = { '\0', 't', 'e', 'm', 'p', '\0' }; EStackIndex old_top = top_estack; push_Float( flt ); /* round to 14 digits, add float tag */ VarStore( Name+5, STOF_ESI, 0, top_estack ); top_estack = old_top; /* restore original top_estack */ Some variables are system protected. These include programs and functions (TI-BASIC or ASM), data variables, graph databases, third-party data-types TI-89 / TI-92 Plus Developer Guide Not for Distribution Beta Version January 26, 2001