Aggregate first(TYPE d) TYPE

d - Operates on decimal, float, integer, string, boolean or location types.
Return the earliest value in the window.

If the window is empty, then NaN is returned for float or decimal types. Otherwise a default-initialized value is returned.

All values in the window are treated identically, including NaN and other IEEE special values.
See Also:
com.apama.aggregates.nth - Use nth for arbitrary positions in the window.