🚀 go-pugleaf

I am new to forth.  Could someone tell me how to do this
in Princeton's VaxForth?:

When loading a file that contains:

8 len data

I want 8 to be pushed (as it will be) and LEN to be defined
such that it has the effect:

here constant data allot  ( with allot getting its parameter)
                          ( from the previous push of 8)

In other words, I want to dynamically create a constant whose name
is taken from the input stream.

Any help would be much appreciated.

Harold Carr    
arpa: CARR@UTAH-20
uucp: harpo!utah-cs!carr