From 5298940fc7798455d701d075b910e0545d3f6048 Mon Sep 17 00:00:00 2001
From: ubq323 <ubq323@ubq323.website>
Date: Fri, 21 Jun 2024 01:05:00 +0100
Subject: proper equality for values; deduplicate constants in compilation

---
 val.c | 11 +++++++++++
 val.h |  1 +
 vm.c  | 11 ++++++++++-
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/val.c b/val.c
index 19f96a0..5a20d09 100644
--- a/val.c
+++ b/val.c
@@ -81,6 +81,17 @@ bool is_truthy(Val v) {
 	return true;
 }
 
+bool val_equal(Val a, Val b) {
+	if (a.ty != b.ty) return false;
+	switch (a.ty) {
+	case TY_NIL: return true;
+	case TY_NUM: return AS_NUM(a) == AS_NUM(b);
+	case TY_BOOL: return AS_BOOL(a) == AS_BOOL(b);
+	case TY_OBJ: return AS_OBJ(a) == AS_OBJ(b);
+	default: return false;
+	}
+}
+
 
 const char *typename_str(Val v) {
 	switch(v.ty) {
diff --git a/val.h b/val.h
index aa20b48..1db122b 100644
--- a/val.h
+++ b/val.h
@@ -31,6 +31,7 @@ void println_val(Val v);
 const char *typename_str(Val v);
 
 bool is_truthy(Val v);
+bool val_equal(Val a, Val b);
 
 
 typedef enum {
diff --git a/vm.c b/vm.c
index e969692..1dc40e0 100644
--- a/vm.c
+++ b/vm.c
@@ -27,11 +27,15 @@ size_t chunk_wbc(State *S, Chunk *ch, uint8_t byte) {
 	return ix;
 }
 size_t chunk_wconst(State *S, Chunk *ch, Val v) {
+	for (int i = 0; i < ch->consts.len; i ++)
+		if (val_equal(v, ch->consts.d[i])) return i;
+
 	if (ch->consts.len == ch->consts.cap) {
 		size_t newsz = (ch->consts.cap == 0 ? 8 : ch->consts.cap *2);
 		ch->consts.d = RENEW_ARR(S, ch->consts.d, Val, ch->consts.cap, newsz);
 		ch->consts.cap = newsz;
 	}
+
 	size_t ix = ch->consts.len;
 	ch->consts.d[ix] = v;
 	ch->consts.len ++;
@@ -149,11 +153,16 @@ int runvm(State *S) {
 			ARITH_OP(OP_SUB, -)
 			ARITH_OP(OP_MUL, *)
 			ARITH_OP(OP_DIV, /)
-			BOOL_OP(OP_EQU, ==)
 			BOOL_OP(OP_CMP, <)
 #undef BINARY_OP
 #undef ARITH_OP
 #undef BOOL_OP
+		case OP_EQU: {
+			Val b = POP();
+			Val a = POP();
+			PUSH(VAL_BOOL(val_equal(a,b)));
+			break;
+		}
 		case OP_MOD: {
 			Val b = POP();
 			Val a = POP();
-- 
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