Merge branch 'master' of ssh://git.gag.com/scm/git/fw/altos

1 files changed, 167 insertions, 0 deletions

diff --git a/src/scheme/ao_scheme_atom.c b/src/scheme/ao_scheme_atom.c
new file mode 100644
index 00000000..cb32b7fe
--- /dev/null
+++ b/src/scheme/ao_scheme_atom.c
@@ -0,0 +1,167 @@
+/*
+ * Copyright © 2016 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "ao_scheme.h"
+
+static int name_size(char *name)
+{
+	return sizeof(struct ao_scheme_atom) + strlen(name) + 1;
+}
+
+static int atom_size(void *addr)
+{
+	struct ao_scheme_atom	*atom = addr;
+	if (!atom)
+		return 0;
+	return name_size(atom->name);
+}
+
+static void atom_mark(void *addr)
+{
+	struct ao_scheme_atom	*atom = addr;
+
+	for (;;) {
+		atom = ao_scheme_poly_atom(atom->next);
+		if (!atom)
+			break;
+		if (ao_scheme_mark_memory(&ao_scheme_atom_type, atom))
+			break;
+	}
+}
+
+static void atom_move(void *addr)
+{
+	struct ao_scheme_atom	*atom = addr;
+	int			ret;
+
+	for (;;) {
+		struct ao_scheme_atom *next = ao_scheme_poly_atom(atom->next);
+
+		if (!next)
+			break;
+		ret = ao_scheme_move_memory(&ao_scheme_atom_type, (void **) &next);
+		if (next != ao_scheme_poly_atom(atom->next))
+			atom->next = ao_scheme_atom_poly(next);
+		if (ret)
+			break;
+		atom = next;
+	}
+}
+
+const struct ao_scheme_type ao_scheme_atom_type = {
+	.mark = atom_mark,
+	.size = atom_size,
+	.move = atom_move,
+	.name = "atom"
+};
+
+struct ao_scheme_atom	*ao_scheme_atoms;
+
+struct ao_scheme_atom *
+ao_scheme_atom_intern(char *name)
+{
+	struct ao_scheme_atom	*atom;
+
+	for (atom = ao_scheme_atoms; atom; atom = ao_scheme_poly_atom(atom->next)) {
+		if (!strcmp(atom->name, name))
+			return atom;
+	}
+#ifdef ao_builtin_atoms
+	for (atom = ao_scheme_poly_atom(ao_builtin_atoms); atom; atom = ao_scheme_poly_atom(atom->next)) {
+		if (!strcmp(atom->name, name))
+			return atom;
+	}
+#endif
+	ao_scheme_string_stash(0, name);
+	atom = ao_scheme_alloc(name_size(name));
+	name = ao_scheme_string_fetch(0);
+	if (atom) {
+		atom->type = AO_SCHEME_ATOM;
+		atom->next = ao_scheme_atom_poly(ao_scheme_atoms);
+		ao_scheme_atoms = atom;
+		strcpy(atom->name, name);
+	}
+	return atom;
+}
+
+ao_poly *
+ao_scheme_atom_ref(ao_poly atom, struct ao_scheme_frame **frame_ref)
+{
+	ao_poly	*ref;
+	struct ao_scheme_frame *frame;
+
+	for (frame = ao_scheme_frame_current; frame; frame = ao_scheme_poly_frame(frame->prev)) {
+		ref = ao_scheme_frame_ref(frame, atom);
+		if (ref) {
+			if (frame_ref)
+				*frame_ref = frame;
+			return ref;
+		}
+	}
+	ref = ao_scheme_frame_ref(ao_scheme_frame_global, atom);
+	if (ref)
+		if (frame_ref)
+			*frame_ref = ao_scheme_frame_global;
+	return ref;
+}
+
+ao_poly
+ao_scheme_atom_get(ao_poly atom)
+{
+	ao_poly *ref = ao_scheme_atom_ref(atom, NULL);
+
+#ifdef ao_builtin_frame
+	if (!ref)
+		ref = ao_scheme_frame_ref(ao_scheme_poly_frame(ao_builtin_frame), atom);
+#endif
+	if (ref)
+		return *ref;
+	return ao_scheme_error(AO_SCHEME_UNDEFINED, "undefined atom %s", ao_scheme_poly_atom(atom)->name);
+}
+
+ao_poly
+ao_scheme_atom_set(ao_poly atom, ao_poly val)
+{
+	ao_poly *ref = ao_scheme_atom_ref(atom, NULL);
+
+	if (!ref)
+		return ao_scheme_error(AO_SCHEME_UNDEFINED, "undefined atom %s", ao_scheme_poly_atom(atom)->name);
+	*ref = val;
+	return val;
+}
+
+ao_poly
+ao_scheme_atom_def(ao_poly atom, ao_poly val)
+{
+	struct ao_scheme_frame	*frame;
+	ao_poly *ref = ao_scheme_atom_ref(atom, &frame);
+
+	if (ref) {
+		if (frame == ao_scheme_frame_current)
+			return ao_scheme_error(AO_SCHEME_REDEFINED, "attempt to redefine atom %s", ao_scheme_poly_atom(atom)->name);
+		*ref = val;
+		return val;
+	}
+	return ao_scheme_frame_add(ao_scheme_frame_current ? ao_scheme_frame_current : ao_scheme_frame_global, atom, val);
+}
+
+void
+ao_scheme_atom_write(ao_poly a)
+{
+	struct ao_scheme_atom *atom = ao_scheme_poly_atom(a);
+	printf("%s", atom->name);
+}