Function Data Type

MDSplus provides a function data type used for describing references to built in native TDI functions. You will not normally need to concern yourself with this data type since it is constructed automatically when you use TDI expression syntax to invoke built in functions. When you specify an expression such as "a + b", MDSplus will compile this into a DTYPE_FUNCTION data item. The function data type consists of a opcode and a list of operands. The opcode is stored as a 16 bit code and the operands can be any MDSplus data type.

a + b

will be compiled into the same function structure as if you had specified:

BUILD_FUNCTION(BUILDIN_OPCODE('ADD'),a,b)

The following table lists some of the functions available for creating and accessing dtype function: