From a2ea2a6ac26a33b72954908a09329af184dd9a1e Mon Sep 17 00:00:00 2001
From: Devine Lu Linvega <aliceffekt@gmail.com>
Date: Sat, 27 Apr 2024 09:24:48 -0700
Subject: [PATCH] Pretty print rules

---
 src/modal.c | 44 ++++++++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/src/modal.c b/src/modal.c
index 8a594e1..c7bc1a4 100644
--- a/src/modal.c
+++ b/src/modal.c
@@ -2,7 +2,7 @@
 
 typedef struct {
 	unsigned int id, refs, ptr;
-	char *a, *b, reg[0x8];
+	char *a, *b, reg[8];
 } Rule;
 
 static int flip, quiet, cycles = 0x10000;
@@ -102,8 +102,8 @@ write_tail(char *s)
 static int
 apply_rule(Rule *r, char *s)
 {
-	unsigned int i, id;
-	char c, *a = r->a, *b = r->b, *origin = dst_, *reg, *regs[0x8];
+	unsigned int i, rid;
+	char c, *a = r->a, *b = r->b, *origin = dst_, *reg, *regs[8];
 	/* phase: clean regs */
 	for(i = 0; i < r->ptr; i++)
 		regs[i] = NULL;
@@ -111,13 +111,13 @@ apply_rule(Rule *r, char *s)
 	while((c = *a++)) {
 		if(c == '?') {
 			char *pcap = walk(s);
-			id = *a++ - '0';
-			if((reg = regs[id])) { /* reg cmp */
+			rid = *a++ - '0';
+			if((reg = regs[rid])) { /* reg cmp */
 				char *rcap = walk(reg), *pp = s;
 				while(reg < rcap || pp < pcap)
 					if(*reg++ != *pp++) return 0;
 			} else /* reg set */
-				regs[id] = s;
+				regs[rid] = s;
 			s = pcap;
 		} else if(c != *s++)
 			return 0;
@@ -127,9 +127,9 @@ apply_rule(Rule *r, char *s)
 	/* phase: write rule */
 	while((c = *b++)) {
 		if(c == '?') {
-			id = *b - '0';
-			if(id < 9 && (reg = regs[id]))
-				b++, write_reg(r->reg[id], reg);
+			rid = *b - '0';
+			if(rid < 9 && (reg = regs[rid]))
+				b++, write_reg(r->reg[rid], reg);
 			else
 				*dst_++ = c;
 		} else
@@ -146,9 +146,9 @@ apply_rule(Rule *r, char *s)
 static int
 find_reg(Rule *r, char reg)
 {
-	int i;
-	for(i = 0; i < (int)r->ptr; i++)
-		if(r->reg[i] == reg) return i;
+	int rid;
+	for(rid = 0; rid < (int)r->ptr; rid++)
+		if(r->reg[rid] == reg) return rid;
 	return -1;
 }
 
@@ -204,6 +204,20 @@ find_rule(char *s, char *cap)
 	return r;
 }
 
+static void
+echo_rule(Rule *r, char *field)
+{
+	char c, *s = field;
+	putc('(', stdout);
+	while((c = *s++)) {
+		int rid;
+		putc(c, stdout);
+		if(c == '?')
+			c = *s++, rid = c - '0', putc(rid < 8 ? r->reg[rid] : c, stdout);
+	}
+	putc(')', stdout), putc(' ', stdout);
+}
+
 static int
 rewrite(void)
 {
@@ -216,7 +230,8 @@ rewrite(void)
 			if(c == '<' && s[1] == '>') {
 				r = rules_++;
 				s = compile_rule(r, rules_ - rules - 1, s + 2);
-				if(!quiet && r->a) printf("<> (%s) (%s)\n", r->a, r->b);
+				if(!quiet && r->a)
+					printf("<> "), echo_rule(r, r->a), echo_rule(r, r->b), putc('\n', stdout);
 				while(*s == ' ') s++;
 				return write_tail(s);
 			}
@@ -225,7 +240,8 @@ rewrite(void)
 				s += 2;
 				while(*s == ' ') s++;
 				cap = walk(s), r = find_rule(s, cap), r->a = 0;
-				if(!quiet && r->a) printf(">< (%s)\n", r->a);
+				if(!quiet && r->a)
+					printf(">< "), echo_rule(r, r->a), putc('\n', stdout);
 				while(*cap == ' ') cap++;
 				return write_tail(cap);
 			}