Add first lisp bits

[fw/altos] / src / lisp / ao_lisp_atom.c

diff --git a/src/lisp/ao_lisp_atom.c b/src/lisp/ao_lisp_atom.c
new file mode 100644 (file)
index 0000000..6528214
--- /dev/null
+++ b/src/lisp/ao_lisp_atom.c
@@ -0,0 +1,107 @@
+/*
+ * 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_lisp.h"
+
+static int name_size(char *name)
+{
+       return sizeof(struct ao_lisp_atom) + strlen(name) + 1;
+}
+
+static int atom_size(void *addr)
+{
+       struct ao_lisp_atom     *atom = addr;
+       if (!atom)
+               return 0;
+       return name_size(atom->name);
+}
+
+static void atom_mark(void *addr)
+{
+       struct ao_lisp_atom     *atom = addr;
+
+       if (atom->next == AO_LISP_ATOM_CONST)
+               return;
+
+       for (;;) {
+               ao_lisp_poly_mark(atom->val);
+               atom = atom->next;
+               if (!atom)
+                       break;
+               if (ao_lisp_mark_memory(atom, atom_size(atom)))
+                       break;
+       }
+}
+
+static void atom_move(void *addr)
+{
+       struct ao_lisp_atom     *atom = addr;
+
+       if (atom->next == AO_LISP_ATOM_CONST)
+               return;
+
+       for (;;) {
+               struct ao_lisp_atom     *next;
+
+               atom->val = ao_lisp_poly_move(atom->val);
+               next = ao_lisp_move_memory(atom->next, atom_size(atom->next));
+               if (!next)
+                       break;
+               atom->next = next;
+               atom = next;
+       }
+}
+
+const struct ao_lisp_mem_type ao_lisp_atom_type = {
+       .mark = atom_mark,
+       .size = atom_size,
+       .move = atom_move,
+};
+
+struct ao_lisp_atom    *atoms;
+
+struct ao_lisp_atom *
+ao_lisp_atom_intern(char *name)
+{
+       struct ao_lisp_atom     *atom;
+       int                     b;
+
+       for (atom = atoms; atom; atom = atom->next) {
+               if (!strcmp(atom->name, name))
+                       return atom;
+       }
+       for (b = 0; ao_lisp_builtins[b]; b++)
+               if (!strcmp(ao_lisp_builtins[b]->name, name))
+                       return (struct ao_lisp_atom *) ao_lisp_builtins[b];
+       if (!atoms)
+               ao_lisp_root_add(&ao_lisp_atom_type, (void **) &atoms);
+       atom = ao_lisp_alloc(name_size(name));
+       if (atom) {
+               atom->type = AO_LISP_ATOM;
+               atom->next = atoms;
+               atoms = atom;
+               strcpy(atom->name, name);
+               atom->val = AO_LISP_NIL;
+       }
+       return atom;
+}
+
+void
+ao_lisp_atom_print(struct ao_lisp_atom *a)
+{
+       fputs(a->name, stdout);
+}