iris

commit f3c5bfda03ab1412ffb98a0d00b91300646040d1
parent 50ab31181588006ba4e2f1e3d3ad56d8d57d24e3
Author: sin <sin@2f30.org>
Date:   Thu, 15 May 2014 11:05:40 +0100

Prepare the ground for more builtins

Diffstat:
M
parser.c
 | 
31
++++++++++++++++++++++---------

1 file changed, 22 insertions(+), 9 deletions(-)
diff --git a/parser.c b/parser.c
@@ -59,11 +59,14 @@ struct object {
 	} d;
 };
 
+static struct object *evalquote(struct object *);
+
 struct {
 	char *name;
 	struct object *o;
+	struct object *(*fn)(struct object *);
 } builtins[] = {
-	{ .name = "quote" },
+	{ .name = "quote", .fn = evalquote },
 };
 
 static int
@@ -242,26 +245,28 @@ sexpression(FILE *in)
 	return NULL;
 }
 
-static int
-quoted(struct object *o)
+struct object *
+evalquote(struct object *o)
 {
 	struct object *car;
 
 	if (o->type == OPair) {
 		car = o->d.p.car;
-		return car->type == OIdentifier &&
-			strcmp(car->d.i.s, "quote") == 0;
+		if (car->type == OIdentifier &&
+		    strcmp(car->d.i.s, "quote") == 0)
+			return o->d.p.cdr->d.p.car;
 	}
-	return 0;
+	return NULL;
 }
 
 struct object *
 eval(struct object *o)
 {
+	size_t i;
 	struct object *otmp;
 
-	switch (o->type) {
 	/* self-evaluating objects */
+	switch (o->type) {
 	case OError:
 	case OEof:
 	case OBoolean:
@@ -270,6 +275,7 @@ eval(struct object *o)
 	case OString:
 		return o;
 	}
+	/* evaluate identifiers */
 	if (o->type == OIdentifier) {
 		if (builtin(o->d.i.s) == 1)
 			return error("cannot eval builtin in this context");
@@ -278,8 +284,12 @@ eval(struct object *o)
 			return error("unbound identifier");
 		return otmp;
 	}
-	if (quoted(o))
-		return o->d.p.cdr->d.p.car; /* cadr */
+	/* evaluate builtins */
+	for (i = 0; i < LEN(builtins); i++) {
+		otmp = builtins[i].fn(o);
+		if (otmp)
+			return otmp;
+	}
 	return error("cannot eval object");
 }
 
@@ -315,6 +325,9 @@ print(struct object *o)
 	case OEof:
 		printf("%s", o->d.eof.s);
 		break;
+	case OIdentifier:
+		printf("%s", o->d.i.s);
+		break;
 	case OBoolean:
 		printf("#%c", o->d.b.v == false ? 'f' : 't');
 		break;