From 966304f09ab32a2b7a135d447b66d348933894ef Mon Sep 17 00:00:00 2001
From: Devine Lu Linvega <aliceffekt@gmail.com>
Date: Mon, 15 Apr 2024 08:47:20 -0700
Subject: [PATCH] Halt after a number of rewrites

---
 src/modal.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/modal.c b/src/modal.c
index eb90197..4a5cf6c 100644
--- a/src/modal.c
+++ b/src/modal.c
@@ -5,7 +5,7 @@ typedef struct {
 	char *a, *b;
 } Rule;
 
-static int flip;
+static int flip, cycles = 0x10000;
 static Rule rules[0x1000], lambda, *rules_ = rules;
 static char dict[0x8000], *dict_ = dict;
 static char bank_a[0x4000], *src_ = bank_a;
@@ -197,9 +197,9 @@ main(int argc, char **argv)
 	if(argc < 2)
 		return !printf("usage: modal [-v] source.modal\n");
 	if(argc < 3 && argv[1][0] == '-' && argv[1][1] == 'v')
-		return !printf("Modal Interpreter, 14 Apr 2024.\n");
+		return !printf("Modal Interpreter, 15 Apr 2024.\n");
 	if(!(f = fopen(argv[1], "r")))
-		return !printf("Invalid Modal file: %s.\n", argv[1]);
+		return !fprintf(stderr, "Invalid Modal file: %s.\n", argv[1]);
 	while(fread(&c, 1, 1, f)) {
 		c = c <= 0x20 ? 0x20 : c;
 		if(w > bank_a) {
@@ -212,6 +212,6 @@ main(int argc, char **argv)
 	while(*(--w) <= ' ') *w = 0;
 	fclose(f);
 	while(rewrite())
-		;
+		if(cycles--) return !fprintf(stderr, "Cycle limit exceeded.\n");
 	return 0;
 }
\ No newline at end of file