Since SRFI 126 is meant to be R6RS compatible where possible, and since
R6RS hash functions accept only one argument, SRFI 126 functions should
accept one argument too.

Here's a sentence I'm going to put into SRFI 125 and SRFI 128, and I
recommend for SRFI 126 as well:

    If hash function authors wish to be backward compatible with the
    reference implementation of SRFI 69, they are advised to write
    their hash functions to accept a second argument and ignore it.

--
John Cowan          http://www.ccil.org/~cowan        xxxxxx@ccil.org
Do I contradict myself?
Very well then, I contradict myself.
I am large, I contain multitudes.
        --Walt Whitman, Leaves of Grass