--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/relpipe-data/examples/guile-file-count-size-sum.sh	Thu Feb 07 16:24:21 2019 +0100
@@ -0,0 +1,28 @@
+#!/bin/bash
+
+# argument: directory path
+# prints file count and sum of file sizes
+
+find "$1" -type f -print0 \
+	| relpipe-in-filesystem \
+		--file path \
+		--file size \
+	| relpipe-tr-guile \
+		--relation 'f.*' \
+		--output-attribute 'count' integer \
+		--output-attribute 'sum'   integer \
+		--before-records '
+			(define $sum   0)
+			(define $count 0)
+			(define return-sum #f)' \
+		--for-each '
+			(set! $sum   (+ $sum   $size) )
+			(set! $count (+ $count 1    ) )' \
+		--where '#f' \
+		--after-records '(set! return-sum #t)' \
+		--has-more-records '
+			(if return-sum
+				(begin (set! return-sum #f) #t)
+				#f
+			)' \
+	| relpipe-out-tabular