From 53b89bcf653d904a3403dfae54e8d622a5e984eb Mon Sep 17 00:00:00 2001
From: Devine Lu Linvega <aliceffekt@gmail.com>
Date: Sun, 28 Apr 2024 18:55:03 -0700
Subject: [PATCH] Isolated device read/write functions

---
 src/modal.c | 59 +++++++++++++++++++++++++++++++++--------------------
 1 file changed, 37 insertions(+), 22 deletions(-)

diff --git a/src/modal.c b/src/modal.c
index 7fcba74..4095b43 100644
--- a/src/modal.c
+++ b/src/modal.c
@@ -31,32 +31,47 @@ walk(char *s)
 	return s;
 }
 
+static void
+device_write(char *s)
+{
+	char c, *cap = walk(s);
+	if(*s == '(') s++, --cap;
+	while(s < cap) {
+		c = *s++;
+		if(c == '\\') {
+			switch(*s++) {
+			case 't': putc(0x09, stdout); break;
+			case 'n': putc(0x0a, stdout); break;
+			case 's': putc(0x20, stdout); break;
+			}
+		} else
+			putc(c, stdout);
+	}
+}
+
+static void
+device_read(char *s)
+{
+	char c;
+	while(fread(&c, 1, 1, stdin) && c >= ' ')
+		*dst_++ = c;
+	if(feof(stdin))
+		*dst_++ = 'E', *dst_++ = 'O', *dst_++ = 'F';
+}
+
 static void
 write_reg(char r, char *reg)
 {
 	char c, *cap = walk(reg);
 	switch(r) {
-	case ':': /* op: output */
-		if(*reg == '(') reg++, --cap;
-		while(reg < cap) {
-			c = *reg++;
-			if(c == '\\') {
-				switch(*reg++) {
-				case 't': putc(0x09, stdout); break;
-				case 'n': putc(0x0a, stdout); break;
-				case 's': putc(0x20, stdout); break;
-				}
-			} else
-				putc(c, stdout);
-		}
+	case '>': /* op: output */
+	case ':':
+		device_write(reg);
 		return;
-	case '~': { /* op: input */
-		while(fread(&c, 1, 1, stdin) && c >= ' ')
-			*dst_++ = c;
-		if(feof(stdin))
-			*dst_++ = 'E', *dst_++ = 'O', *dst_++ = 'F';
+	case '<': /* op: input */
+	case '~':
+		device_read(reg);
 		return;
-	}
 	case '^': /* op: join */
 		if(*reg == '(') reg++, --cap;
 		while(reg < cap && (c = *reg++))
@@ -196,7 +211,7 @@ rewrite(void)
 				s += 2;
 				while(*s == ' ') s++;
 				cap = walk(s), r = find_rule(s, cap);
-				if(r != NULL){
+				if(r != NULL) {
 					if(!quiet)
 						fprintf(stderr, ">< (%s) (%s)\n", r->a, r->b);
 					r->a = 0;
@@ -208,7 +223,7 @@ rewrite(void)
 			if(c == '<' && s[1] == '>') {
 				r = rules_, r->id = rules_ - rules - 1;
 				s = parse_frag(&r->b, parse_frag(&r->a, s + 2));
-				if(*r->a){
+				if(*r->a) {
 					if(!quiet)
 						fprintf(stderr, "<> (%s) (%s)\n", r->a, r->b);
 					rules_++;
@@ -273,7 +288,7 @@ main(int argc, char **argv)
 	while(rewrite() && ++rw)
 		if(!cycles--) return !fprintf(stderr, "Modal rewrites exceeded.\n");
 	if(!quiet) {
-		while(rules_-- > rules){
+		while(rules_-- > rules) {
 			if(!rules_->refs && rules_->a)
 				fprintf(stderr, "-- Unused rule: %d <> (%s) (%s)\n", rules_->id, rules_->a, rules_->b);
 			if(debug && rules_->a)