From d0c3bd9ccbb5020f55fdbe456f598095f2071347 Mon Sep 17 00:00:00 2001
From: Bernd Jendrissek <bernd.jendrissek@gmail.com>
Date: Mon, 28 Jan 2008 01:24:38 +0000
Subject: [PATCH] lisp_car(): Utility function to simplify code.

---
 lisp/lisp.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/lisp/lisp.c b/lisp/lisp.c
index ac88552..da6d9cc 100644
--- a/lisp/lisp.c
+++ b/lisp/lisp.c
@@ -134,6 +134,11 @@ void pair_free(struct pair *p)
 	free(p);
 }
 
+union value_pointer lisp_car(union value_pointer v)
+{
+	return get_pair(v)->car;
+}
+
 struct binding *binding_new(struct environment *env,
 			    char const *name,
 			    union value_pointer value)
@@ -323,7 +328,7 @@ void pretty_print(union value_pointer v)
 			if (i.vp_pair != v.vp_pair) {
 				printf(" ");
 			}
-			pretty_print(get_pair(i)->car);
+			pretty_print(lisp_car(i));
 		}
 		if (pointer_type(i) != 3) {
 			printf(" . ");
@@ -369,7 +374,7 @@ union value_pointer builtin_eval(struct environment *env,
 		args.vp_pair = pair_new();
 		args.vp_pair->car = builtin_eval(env, subeval_arg);
 
-		if (get_pair(args.vp_pair->car)->car.vp_opaque == opaque_builtin_function) {
+		if (lisp_car(args.vp_pair->car).vp_opaque == opaque_builtin_function) {
 			arglink = &args.vp_pair->cdr;
 
 			for (list = get_pair(list->cdr); list != NULL; list = get_pair(list->cdr)) {
@@ -433,7 +438,7 @@ union value_pointer builtin_car(struct environment *env,
 {
 	union value_pointer retval;
 
-	retval = get_pair(rest->car)->car;
+	retval = lisp_car(rest->car);
 
 	return retval;
 }
@@ -455,7 +460,7 @@ union value_pointer builtin_cons(struct environment *env,
 
 	retval.vp_pair = pair_new();
 	retval.vp_pair->car = rest->car;
-	retval.vp_pair->cdr = get_pair(rest->cdr)->car;
+	retval.vp_pair->cdr = lisp_car(rest->cdr);
 	pointer_mark(&retval, 3);
 
 	return retval;
@@ -467,7 +472,7 @@ union value_pointer builtin_eq_p(struct environment *env,
 	union value_pointer a, b;
 
 	a = rest->car;
-	b = get_pair(rest->cdr)->car;
+	b = lisp_car(rest->cdr);
 
 	if (pointer_type(a) != pointer_type(b)) {
 		return constant_false;
@@ -510,7 +515,7 @@ union value_pointer builtin_if(struct environment *env,
 	pointer_mark(&retval, 3);
 
 	condition = rest->car;
-	consequent = get_pair(rest->cdr)->car;
+	consequent = lisp_car(rest->cdr);
 	alternate = get_pair(rest->cdr)->cdr;
 
 	p = pair_new();
@@ -521,7 +526,7 @@ union value_pointer builtin_if(struct environment *env,
 	    condition.vp_charseq != constant_false.vp_charseq) {
 		p->car = consequent;
 	} else if (get_pair(alternate) != NULL) {
-		p->car = get_pair(alternate)->car;
+		p->car = lisp_car(alternate);
 	} else {
 		pair_free(p);
 		return retval;
-- 
2.11.4.GIT