I've seen the use of the word transducer first in SERIES, a Common Lisp library for iteration by Richard C. Waters. for example: https://www.cs.cmu.edu/Groups/

I've seen the use of the word transducer first in SERIES, a Common Lisp library for iteration by Richard C. Waters. for example: https://www.cs.cmu.edu/Groups/AI/html/cltl/clm/node352.html#SECTION003423000000000000000 https://www.cs.cmu.edu/Groups/AI/html/cltl/clm/node352.html#...