Macro bind_aggr_fn

macro_rules! bind_aggr_fn {
    ($AGGR_FUNC: ident, $VM: ident, $ARGS:expr, $DATA_TYPE: expr $(, $EXPR_ARGS: ident)*) => { ... };
}

The macro for binding function in datafusion_physical_expr::expressions(most of them are aggregate function)

• first arguments is the name of datafusion expression function like Avg
• second is the python virtual machine ident vm
• following is the actual args passing in(as a slice).i.e.&[values.to_arrow_array()]
• the data type of passing in args, i.e: Datatype::Float64
• lastly ARE names given to expr of those function, i.e. expr0, expr1,….