From 09ae4fb60f7e45e9dd91f46cda60c20ed0b7b488 Mon Sep 17 00:00:00 2001
From: Mart Lubbers <mart@martlubbers.net>
Date: Wed, 23 May 2018 12:03:50 +0200
Subject: [PATCH] remove smart allocations, back to bruteforce

---
 lambda.h |  1 -
 lambda.y |  6 ++----
 mem.c    | 30 +++++++++++++-----------------
 reduce.c | 11 ++---------
 4 files changed, 17 insertions(+), 31 deletions(-)

diff --git a/lambda.h b/lambda.h
index 54c23e3..d9921d6 100644
--- a/lambda.h
+++ b/lambda.h
@@ -9,7 +9,6 @@
 enum lambda_which {lambda_ident, lambda_abs, lambda_app};
 struct lambda {
 	enum lambda_which which;
-	unsigned int refcount;
 	union {
 		struct {
 			char *ident;
diff --git a/lambda.y b/lambda.y
index 3aff9c1..9cde7e1 100644
--- a/lambda.y
+++ b/lambda.y
@@ -31,9 +31,7 @@ int yywrap()
 
 struct lambda *make_lambda()
 {
-	struct lambda *t = malloc(sizeof (struct lambda));
-	t->refcount = 1;
-	return t;
+	return malloc(sizeof (struct lambda));
 }
 
 struct lambda *make_ident(char *i)
@@ -148,7 +146,7 @@ lambda
 			struct lambda *t = $1;
 			printf("     ");
 			for(unsigned int i = 0; i<999; i++)
-				if(!lambda_reduce(&t, &t, false))
+				if(!lambda_reduce(&t, &t, true))
 					break;
 			lambda_print(t, NULL);
 			putchar('\n');
diff --git a/mem.c b/mem.c
index 4d73188..270679b 100644
--- a/mem.c
+++ b/mem.c
@@ -5,24 +5,20 @@
 void lambda_free(struct lambda *t)
 {
 	if(t != NULL){
-		if(t->refcount == 1){
-			switch(t->which){
-			case lambda_ident:
-				free(t->data.identifier.ident);
-				break;
-			case lambda_abs:
-				free(t->data.abstraction.ident);
-				lambda_free(t->data.abstraction.expr);
-				break;
-			case lambda_app:
-				lambda_free(t->data.application.expr1);
-				lambda_free(t->data.application.expr2);
-				break;
-			}
-			free(t);
-		} else {
-			t->refcount--;
+		switch(t->which){
+		case lambda_ident:
+			free(t->data.identifier.ident);
+			break;
+		case lambda_abs:
+			free(t->data.abstraction.ident);
+			lambda_free(t->data.abstraction.expr);
+			break;
+		case lambda_app:
+			lambda_free(t->data.application.expr1);
+			lambda_free(t->data.application.expr2);
+			break;
 		}
+		free(t);
 	}
 }
 
diff --git a/reduce.c b/reduce.c
index bbe52de..7bd170c 100644
--- a/reduce.c
+++ b/reduce.c
@@ -16,8 +16,7 @@ void lambda_beta(struct lambda *binding, struct lambda **body, struct lambda *ta
 	case lambda_ident:
 		if((*body)->data.identifier.binding == binding){
 			lambda_free(*body);
-			*body = target;
-			target->refcount++;
+			*body = copy(target);
 		}
 		break;
 	case lambda_abs:
@@ -42,17 +41,11 @@ bool lambda_reduce(struct lambda **t, struct lambda **total, bool applicative)
 			if(lhs(t)->data.abstraction.strict)
 				lambda_reduce(&rhs(t), total, true);
 
-			if(lhs(t) == rhs(t)){
-				lhs(t)->refcount--;
-				rhs(t) = copy(rhs(t));
-			}
-
 			//In this abstraction we substitute the result with the rhs
 			lambda_print(*total, *t);
 			lambda_beta(lhs(t), &lhs(t)->data.abstraction.expr, rhs(t), *total);
 
-			struct lambda *newt = lhs(t)->data.abstraction.expr;
-			lhs(t)->data.abstraction.expr->refcount++;
+			struct lambda *newt = copy(lhs(t)->data.abstraction.expr);
 			lambda_free(*t);
 			*t = newt;
 
-- 
2.20.1