returns a hunk formatter procedure of the specified types; the following formats are supported:
- ed(1) script
- normal diff format
- rcs(1) diff script
- context diff format
Each hunk formatter procedure is of the form LAMBDA OUT-PORT HUNK-LIST, except for the context formatter, which is of the form LAMBDA OUT-PORT HUNK-LIST FNAME1 TSTAMP1 FNAME2 TSTAMP2, where the timestamp and filename arguments are strings. Please see the diff(1) manual for a detailed description of each format.