From: Elijah Cohen <eli@eli173.com>
Date: Thu, 18 Sep 2025 23:37:47 +0000 (-0500)
Subject: reference counting
X-Git-Url: https://git.eli173.com/?a=commitdiff_plain;h=a547ba4d0ac1d279bd5f4d82aa7ce2288a362dd7;p=klapaucius

reference counting
---

diff --git a/klsrc/combinators.kl b/klsrc/combinators.kl
index 431ef57..0bee665 100644
--- a/klsrc/combinators.kl
+++ b/klsrc/combinators.kl
@@ -27,3 +27,5 @@
 (def C3 (C* (B C2)))
 
 (def Cn (Z (B (S (C (eq 0) C)) (B (B (B C)) (B D (C B (C - 1)))))))
+
+(def C?n (Z (B (S (C (eq 0) C)) (B (S (R B (B C))) (C B (C - 1))))))
\ No newline at end of file
diff --git a/klsrc/util.kl b/klsrc/util.kl
index 8e8a40c..6cb8483 100644
--- a/klsrc/util.kl
+++ b/klsrc/util.kl
@@ -1,4 +1,6 @@
 
+(def printthen (D (D evalarg (K I) print)))
+
 (def range (abstract-rec (eq 0) (C cons) (C - 1) nil))
 
 (def x-times-n (C (C (D abstract-rec (eq 0) (D B K cons)) (C - 1)) nil))
diff --git a/src/eval.c b/src/eval.c
index d07236d..f48e179 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -65,10 +65,12 @@ Sexpr* apply_builtin(Sexpr* func, Sexpr* rest, Sexpr* env) {
 	if(func->type != BUILTIN) {
 		return dispatch_others(func, rest, env);
 	}
+	// should i find a nice way to move these next few lines to its own function in sexpr.c?
 	Sexpr* ret = malloc(sizeof(Sexpr));
 	ret->type = BUILTIN;
 	ret->value.b.opcode = func->value.b.opcode;
 	ret->value.b.args = cons(clone(car(rest)), clone(func->value.b.args));
+	ret->refcount = 1;
 	Sexpr* cdrrest = clone(cdr(rest));
 	sexpr_free(rest);
 	return dispatch(ret, cdrrest, env);
diff --git a/src/sexpr.c b/src/sexpr.c
index f57edc8..bac1d11 100644
--- a/src/sexpr.c
+++ b/src/sexpr.c
@@ -14,6 +14,7 @@ Sexpr* from_nil() {
 	Sexpr* ret = malloc(sizeof(Sexpr));
 	ret->type = NIL;
 	ret->value.n = NULL;
+	ret->refcount = 1;
 	return ret;
 }
 
@@ -21,6 +22,7 @@ Sexpr* from_t() {
 	Sexpr* ret = malloc(sizeof(Sexpr));
 	ret->type = T;
 	ret->value.t = NULL;
+	ret->refcount = 1;
 	return ret;
 }
 
@@ -29,6 +31,7 @@ Sexpr* from_sym(char* s) {
 	Sexpr* ret = malloc(sizeof(Sexpr));
 	ret->type = SYM;
 	ret->value.s = strdup(s);
+	ret->refcount = 1;
 	return ret;
 }
 
@@ -36,6 +39,7 @@ Sexpr* from_string(char* s) {
 	Sexpr* ret = malloc(sizeof(Sexpr));
 	ret->type = STR;
 	ret->value.str = strdup(s);
+	ret->refcount = 1;
 	return ret;
 }
 
@@ -43,6 +47,7 @@ Sexpr* from_uint(K_UINT_TYPE u) {
 	Sexpr* ret = malloc(sizeof(Sexpr));
 	ret->type = UINT;
 	ret->value.u = u;
+	ret->refcount = 1;
 	return ret;
 }
 
@@ -51,6 +56,7 @@ Sexpr* from_opcode(uint64_t u) {
 	ret->type = BUILTIN;
 	ret->value.b.opcode = u;
 	ret->value.b.args = from_nil();
+	ret->refcount = 1;
 	return ret;
 }
 
@@ -58,6 +64,7 @@ Sexpr* from_quote(Sexpr* s) {
 	Sexpr* ret = malloc(sizeof(Sexpr));
 	ret->type = QUOTE;
 	ret->value.q = s;
+	ret->refcount = 1;
 	return ret;
 }
 
@@ -65,6 +72,7 @@ Sexpr* from_pointer(void* p) {
 	Sexpr* ret = malloc(sizeof(Sexpr));
 	ret->type = PTR;
 	ret->value.p = p;
+	ret->refcount = 1;
 	return ret;
 }
 
@@ -75,6 +83,7 @@ Sexpr* cons(Sexpr* car, Sexpr* cdr) {
 	c->cdr = cdr;
 	s->type = CONS;
 	s->value.c = c;
+	s->refcount = 1;
 	return s;
 }
 
@@ -129,6 +138,10 @@ Sexpr* equal(Sexpr* a, Sexpr* b) {
 }
 
 void sexpr_free(Sexpr* s) {
+	if(s->refcount > 1) {
+		s->refcount--;
+		return;
+	}
 	if(s->type == CONS) {
 		sexpr_free(car(s));
 		sexpr_free(cdr(s));
@@ -150,6 +163,9 @@ void sexpr_free(Sexpr* s) {
 }
 
 Sexpr* clone(Sexpr* s) {
+	s->refcount++;
+	return s;
+	/*
 	Sexpr* ret;
 	switch(s->type) {
 	case UINT:
@@ -184,6 +200,7 @@ Sexpr* clone(Sexpr* s) {
 		break;
 	}
 	return ret;
+	*/
 }
 
 
diff --git a/src/types.h b/src/types.h
index eaff3ab..583aa07 100644
--- a/src/types.h
+++ b/src/types.h
@@ -32,6 +32,7 @@ typedef struct Builtin {
 
 typedef struct Sexpr {
 	Sexpr_Type type;
+	size_t refcount;
 	union {
 		K_UINT_TYPE u;
 		char* str;