This functionconverts a variable to string. When the variable is already a string then it returns the pointer to the variable. When the variable is long or double sprintf is used to convert the number to string.
When the conversion from number to string is done the result is always a newly allocated mortal. In other words
this conversion routine is safe, not modifying the argument memory object.
pFixSizeMemoryObject execute_Convert2String(pExecuteObject pEo,
pFixSizeMemoryObject pVar,
pMortalList pMyMortal
){