From 294d8a9737c9d6e6f01d642abc8a0c5d43c40487 Mon Sep 17 00:00:00 2001
From: Ekaitz Zarraga <ekaitz@elenq.tech>
Date: Thu, 24 Aug 2023 19:06:40 +0200
Subject: [PATCH] mes: iota: Make compatible with Guile.

* mes/module/mes/scm.mes (iota): Throw exception when n < 0.
* tests/scm.test: Import (mes catch).
("iota -1"): Rewrite with exception handling.
---
 mes/module/mes/scm.mes |  7 +++++--
 tests/scm.test         | 10 +++++++++-
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/mes/module/mes/scm.mes b/mes/module/mes/scm.mes
index dadd3589..5700e179 100644
--- a/mes/module/mes/scm.mes
+++ b/mes/module/mes/scm.mes
@@ -2,6 +2,7 @@
 
 ;;; GNU Mes --- Maxwell Equations of Software
 ;;; Copyright © 2016,2017,2018,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+;;; Copyright © 2023 Ekaitz Zarraga <ekaitz@elenq.tech>
 ;;;
 ;;; This file is part of GNU Mes.
 ;;;
@@ -164,8 +165,10 @@
       (list-tail (cdr x) (- n 1))))
 
 (define (iota n)
-  (if (<= n 0) '()
-      (append2 (iota (- n 1)) (list (- n 1)))))
+  (cond
+    ((< n 0) (throw 'wrong-type-arg n))
+    ((= n 0) '())
+    (else (append2 (iota (- n 1)) (list (- n 1))))))
 
 (define (reverse lst)
   (let loop ((lst lst) (r '()))
diff --git a/tests/scm.test b/tests/scm.test
index a19fcd16..a3b14a59 100755
--- a/tests/scm.test
+++ b/tests/scm.test
@@ -10,6 +10,7 @@ exec ${MES-bin/mes} --no-auto-compile -L ${0%/*} -L module -C module -e '(tests
 
 ;;; GNU Mes --- Maxwell Equations of Software
 ;;; Copyright © 2016,2017,2018,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+;;; Copyright © 2023 Ekaitz Zarraga <ekaitz@elenq.tech>
 ;;;
 ;;; This file is part of GNU Mes.
 ;;;
@@ -30,6 +31,8 @@ exec ${MES-bin/mes} --no-auto-compile -L ${0%/*} -L module -C module -e '(tests
   #:use-module (mes mes-0)
   #:use-module (mes test))
 
+(mes-use-module (mes catch))
+
 (cond-expand
  (mes
   (primitive-load "module/mes/test.scm"))
@@ -131,7 +134,12 @@ exec ${MES-bin/mes} --no-auto-compile -L ${0%/*} -L module -C module -e '(tests
     '() (iota 0))
 
 (pass-if-equal "iota -1"
-               '() (iota -1))
+  'iota-negative-length
+  (catch 'wrong-type-arg
+    (lambda ()
+      (iota -1))
+    (lambda (key . args)
+      'iota-negative-length)))
 
 (pass-if "cond-expand" (sequal? (cond-expand (foobar #f) (mes (display ": pass: *YAY*") 'mes) (guile (display ": pass: *GUILE*") 'mes)) 'mes))