BEGIN {

	false = 0

	true = 1

	fpat[1] = "([^,]*)|(\"[^\"]+\")"

	fpat[2] = fpat[1]

	fpat[3] = fpat[1]

	fpat[4] = "aa+"

	fpat[5] = fpat[4]

	fpat[6] = "[a-z]"

	data[1] = "Robbins,,Arnold,"

	data[2] = "Smith,,\"1234 A Pretty Place, NE\",Sometown,NY,12345-6789,USA"

	data[3] = "Robbins,Arnold,\"1234 A Pretty Place, NE\",Sometown,NY,12345-6789,USA"

	data[4] = "bbbaaacccdddaaaaaqqqq"

	data[5] = "bbbaaacccdddaaaaaqqqqa" # should get trailing qqqa

	data[6] = "aAbBcC"

	for (i = 1; i in data; i++) {

		printf("Splitting: <%s>\n", data[i])

		n = mypatsplit(data[i], fields, fpat[i], seps)

		m = patsplit(data[i], fields2, fpat[i], seps2)

		print "n =", n, "m =", m

		if (n != m) {

			printf("ERROR: counts wrong!\n") > "/dev/stderr"

			exit 1

		}

		for (j = 1; j <= n; j++) {

			printf("fields[%d] = <%s>\tfields2[%d] = <%s>\n", j, fields[j], j, fields2[j])

			if (fields[j] != fields2[j]) {

				printf("ERROR: data %d, field %d mismatch!\n", i, j) > "/dev/stderr"

				exit 1

			}

		}

		for (j = 0; j in seps; j++) {

			printf("seps[%d] = <%s>\tseps2[%d] = <%s>\n", j, seps[j], j, seps2[j])

			if (seps[j] != seps2[j]) {

				printf("ERROR: data %d, separator %d mismatch!\n", i, j) > "/dev/stderr"

				exit 1

			}

		}

	}

}

function mypatsplit(string, array, pattern, seps,

			eosflag, non_empty, nf) # locals

{

	delete array

	delete seps

	if (length(string) == 0)

		return 0

	eosflag = non_empty = false

	nf = 0

	while (match(string, pattern)) {

		if (RLENGTH > 0) {	# easy case

			non_empty = true

			if (! (nf in seps)) {

				if (RSTART == 1)	# match at front of string

					seps[nf] = ""

				else

					seps[nf] = substr(string, 1, RSTART - 1)

			}

			array[++nf] = substr(string, RSTART, RLENGTH)

			string = substr(string, RSTART+RLENGTH)

			if (length(string) == 0)

				break

		} else if (non_empty) {

			# last match was non-empty, and at the

			# current character we get a zero length match,

			# which we don't want, so skip over it

			non_empty = false

			seps[nf] = substr(string, 1, 1)

			string = substr(string, 2)

		} else {

			# 0 length match

			if (! (nf in seps)) {

				if (RSTART == 1)

					seps[nf] = ""

				else

					seps[nf] = substr(string, 1, RSTART - 1)

			}

			array[++nf] = ""

			if (! non_empty && ! eosflag) { # prev was empty

				seps[nf] = substr(string, 1, 1)

			}

			if (RSTART == 1) {

				string = substr(string, 2)

			} else {

				string = substr(string, RSTART + 1)

			}

			non_empty = false

		}

		if (length(string) == 0) {

			if (eosflag)

				break

			else

				eosflag = true

		}

	}

	if (length(string) > 0)

		seps[nf] = string

	return length(array)

}