m4 and newlines?

[Mike]

I have a macro working:

define(`domain', `ifelse($#, 0, , $#, 1, ``domain $1'', ``domain' $1 
domain(shift($@))')')
domain(`a', `b', `c')

that returns:

domain a domain b domain c

I want it to return:

domain a
domain b
domain c

How do I cause a newline? I tried define(`newline', `esyscmd(echo)'), but
that didn't seem to do right.

Mike