From d4b7a0a25c2683c124ce8151c5ebf92e034491f4 Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cdo@wip.sh>
Date: Sun, 27 Oct 2024 13:55:12 +0000
Subject: [PATCH] Revert "Use char instead of int for FSA rule input"

This reverts commit eb22abfb1b6dbdf6dc702e3d9d99314cbbb22d7b.
---
 lib/fsa.c         |  3 ++-
 lib/include/fsa.h | 11 ++++++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/lib/fsa.c b/lib/fsa.c
index 9d73a88..a4611aa 100644
--- a/lib/fsa.c
+++ b/lib/fsa.c
@@ -47,10 +47,11 @@ int fsa_add_state(fsa_t *fsa)
 	return fsa->count++;
 }
 
-void fsa_add_rule(fsa_t *fsa, int from, int to, char input)
+void fsa_add_rule(fsa_t *fsa, int from, int to, int input)
 {
 	assert(fsa->count > from);
 	assert(fsa->count > to);
+	assert(input < ALPHABET_SIZE);
 
 	fsa_state_t *state = &fsa->states[from];
 	if (state->count >= state->capacity) {
diff --git a/lib/include/fsa.h b/lib/include/fsa.h
index 7eb474e..85ee342 100644
--- a/lib/include/fsa.h
+++ b/lib/include/fsa.h
@@ -8,9 +8,14 @@
 
 #include <stdbool.h>
 
+#define CHAR_COUNT 256
+#define ALPHABET_SIZE (CHAR_COUNT + 1)
+
+// Use one more than any valid char to represent empty string
+#define EPSILON CHAR_COUNT
+
 typedef struct {
-	int next;
-	char input;
+	int input, next;
 } fsa_rule_t;
 
 typedef struct {
@@ -28,6 +33,6 @@ void fsa_init(fsa_t *fsa);
 void fsa_free(const fsa_t *fsa);
 
 int fsa_add_state(fsa_t *fsa);
-void fsa_add_rule(fsa_t *fsa, int from, int to, char input);
+void fsa_add_rule(fsa_t *fsa, int from, int to, int input);
 
 #endif