The preferred activity in your design is more like for-each family, say, handle the result inside the proc without return result. So maybe it should be named as for-each-*-in-file, which is more understandable in the first glance.

Best regards.

On Tue, Dec 17, 2024, 13:31 Adam Faiz <adam.faiz@disroot.org> wrote:

From 258d20a9665e6f845a167258c33374a00e734885 Mon Sep 17 00:00:00 2001
From: AwesomeAdam54321 <adam.faiz@disroot.org>
Date: Tue, 17 Dec 2024 12:20:52 +0800
Subject: [PATCH] test-suite: Add tests for `for-rdelim-in-port`-related
 functions.

* test-suite/tests/ports.test: Add test cases for
`for-delimited-in-port` and `for-line-in-file`.
---
 test-suite/tests/ports.test | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/test-suite/tests/ports.test b/test-suite/tests/ports.test
index bec5e356c..15d515f1f 100644
--- a/test-suite/tests/ports.test
+++ b/test-suite/tests/ports.test
@@ -2089,6 +2089,28 @@
           (not (string-index (%search-load-path (basename (test-file)))
                              #\\))))))

+(let ((lst '())
+      (lines '())
+      (string "line1\nline2\nline3")
+      (filename (test-file)))
+  (call-with-input-string
+      "A\0B\0C"
+    (lambda (port)
+      (pass-if "for-delimited-in-port returns true upon completion"
+        (for-delimited-in-port port
+                               (lambda (entry)
+                                 (set! lst (cons entry lst)))
+                               #:delims "\0")
+        (equal? lst '("C" "B" "A")))))
+  (let ((port (open-output-file filename)))
+    (display string port)
+    (close-port port))
+  (pass-if "for-line-in-file returns true upon completion"
+    (for-line-in-file filename
+                      (lambda (line)
+                        (set! lines (cons line lines))))
+    (equal? lines '("line3" "line2" "line1"))))
+
 (delete-file (test-file))

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