Users of lib/sorter.h:  (WARNING: Obsolete, corresponds to v3.9 or even v3.8)

centrum/indexer/patch-index.c		u32		oid
gather/daemon/expire.c			variable	complex
gather/daemon/gc.c			variable	complex
gather/daemon/gc.c			variable	hash
gather/shepherd/shep-cleanup.c		5 bytes		oid				4 min
gather/shepherd/shep-cleanup.c		fixed		hash				35 min
gather/shepherd/shep-export.c		fixed		oid				9 min
gather/shepherd/shep-export.c		fixed		weight
gather/shepherd/shep-plan.c		fixed		weight + oid			in mem
gather/shepherd/shep-plan.c		fixed		site ptr + complex		in mem
gather/shepherd/shep-record.c		fixed		reducible to int		in mem
gather/shepherd/shep-record.c		fixed		oid				in mem
gather/shepherd/shep.c			fixed		oid
gather/shepherd/shep.c			fixed		hash
gather/shepherd/shep-cork.c		fixed		hash + int			20 min
gather/shepherd/shep-feedback.c		fixed		hash
gather/shepherd/shep-merge.c		fixed		hash + int
gather/shepherd/shep-merge.c		fixed		complex (probably can create monotone hashes for that)	38 min
gather/shepherd/shep-recover.c		fixed		fp + more
gather/shepherd/shep-select.c		fixed		weight (non-triv) + hash	21 min
indexer/backlinker.c			8 bytes		int
indexer/feedback-gath.c			fixed		hash + complex			7 min
indexer/fpsort.c			fixed		hash + oid			9 min
indexer/keywords.c			fixed		complex multi-pass
indexer/labelsort.c			variable	oid + complex			2:00
indexer/mergesigns.c			fixed		complex, but has hashes		1:33
indexer/mergesums.c			fixed		hash
indexer/mkgraph.c			complex		complex (with melding) (probably can be replaced by sorting edges and melding afterwards)	34 min
indexer/psort.c				fixed		hash + oid			2 min
indexer/reftexts.c			fixed		hash
indexer/reftexts.c			fixed		via merges			3:30
indexer/reftexts.c			fixed		oid + int
indexer/resolve.c			fixed		hash				1:00 + 3:45
indexer/resolve.c			fixed		masked int			22 min
indexer/ssort.c				variable	hash (with melding)		1:30
indexer/wsort.c				variable	id (with melding)		7:20
lang/lang-tables.c			fixed		complex
lang/stem-dict-gen.c			variable	hash (with melding)

Users of lib/arraysort.h on big arrays:

indexer/chewer.c			fixed		hash + others
indexer/chewer.c			u32		id
indexer/lexfreq.c			ptr		indirect int
indexer/lexorder.c			ptr		complex
indexer/lexorder.c			ptr		complex
indexer/lexsort.c			ptr		complex

Interface:

Key structure		fixed aligned / fixed unaligned / variable
Data structure		none / given by data_len(key) function
Key I/O			default (breadb/bwriteb or attempt direct I/O) / user-defined
Data I/O		always built-in
Input			file / fastbuf / generator function
			+ delete input ASAP flag
Output			file / fastbuf / consumer function
Key comparison		comparison function
			monotone hash function
			preliminary comparison function (?)
Key merging		none / guaranteed unique / user-defined merge function:
				multi-way merge in memory
				2-way merge on fastbufs