iris

commit 6f472dca9eddb30dc8fbb108200442242dbba022
parent eaa2a603032f55ad4d61b3e31df8de7534f6ddbb
Author: sin <sin@2f30.org>
Date:   Thu, 15 May 2014 16:02:19 +0100

Add plus builtin

Diffstat:
M
parser.c
 | 
27
+++++++++++++++++++++++++++

1 file changed, 27 insertions(+), 0 deletions(-)
diff --git a/parser.c b/parser.c
@@ -62,6 +62,7 @@ struct object {
 static struct object *evaldefine(struct object *);
 static struct object *evalif(struct object *);
 static struct object *evalok(struct object *);
+static struct object *evalplus(struct object *);
 static struct object *evalquote(struct object *);
 static struct object *evalset(struct object *);
 
@@ -73,6 +74,7 @@ struct {
 	{ .name = "define", .fn = evaldefine },
 	{ .name = "if",     .fn = evalif     },
 	{ .name = "ok",     .fn = evalok     },
+	{ .name = "plus",   .fn = evalplus   },
 	{ .name = "quote",  .fn = evalquote  },
 	{ .name = "set",    .fn = evalset    },
 };
@@ -352,6 +354,31 @@ evalok(struct object *o)
 }
 
 static struct object *
+doplus(struct object *o, struct object *n)
+{
+	if (!car(o))
+		return n;
+	if (car(o)->type != ONumber)
+		return error("expected number");
+	n->d.n.v += car(o)->d.n.v;
+	return doplus(cdr(o), n);
+}
+
+static struct object *
+evalplus(struct object *o)
+{
+	struct object *ocar;
+
+	if (o->type != OPair)
+		return NULL;
+	ocar = car(o);
+	if (ocar->type != OIdentifier ||
+	    strcmp(ocar->d.i.s, "plus") != 0)
+		return NULL;
+	return doplus(cdr(o), number(0));
+}
+
+static struct object *
 evalquote(struct object *o)
 {
 	struct object *ocar;