+/*
+ * 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.
+ */
+
+#define DBG_EVAL 0
+#include "ao_lisp.h"
+
+int
+lambda_size(void *addr)
+{
+ (void) addr;
+ return sizeof (struct ao_lisp_lambda);
+}
+
+void
+lambda_mark(void *addr)
+{
+ struct ao_lisp_lambda *lambda = addr;
+
+ ao_lisp_poly_mark(lambda->code, 0);
+ ao_lisp_poly_mark(lambda->frame, 0);
+}
+
+void
+lambda_move(void *addr)
+{
+ struct ao_lisp_lambda *lambda = addr;
+
+ ao_lisp_poly_move(&lambda->code, 0);
+ ao_lisp_poly_move(&lambda->frame, 0);
+}
+
+const struct ao_lisp_type ao_lisp_lambda_type = {
+ .size = lambda_size,
+ .mark = lambda_mark,
+ .move = lambda_move,
+};
+
+static int
+ao_lisp_cons_length(struct ao_lisp_cons *cons)
+{
+ int len = 0;
+ while (cons) {
+ len++;
+ cons = ao_lisp_poly_cons(cons->cdr);
+ }
+ return len;
+}
+
+void
+ao_lisp_lambda_print(ao_poly poly)
+{
+ struct ao_lisp_lambda *lambda = ao_lisp_poly_lambda(poly);
+ struct ao_lisp_cons *cons = ao_lisp_poly_cons(lambda->code);
+
+ printf("(");
+ printf("%s", ao_lisp_args_name(lambda->args));
+ while (cons) {
+ printf(" ");
+ ao_lisp_poly_print(cons->car);
+ cons = ao_lisp_poly_cons(cons->cdr);
+ }
+ printf(")");
+}
+
+ao_poly
+ao_lisp_lambda_alloc(struct ao_lisp_cons *code, int args)
+{
+ struct ao_lisp_lambda *lambda = ao_lisp_alloc(sizeof (struct ao_lisp_lambda));
+ struct ao_lisp_cons *arg;
+ int f;
+
+ if (!lambda)
+ return AO_LISP_NIL;
+
+ if (!ao_lisp_check_argc(_ao_lisp_atom_lambda, code, 2, 2))
+ return AO_LISP_NIL;
+ if (!ao_lisp_check_argt(_ao_lisp_atom_lambda, code, 0, AO_LISP_CONS, 1))
+ return AO_LISP_NIL;
+ f = 0;
+ arg = ao_lisp_poly_cons(ao_lisp_arg(code, 0));
+ while (arg) {
+ if (ao_lisp_poly_type(arg->car) != AO_LISP_ATOM)
+ return ao_lisp_error(AO_LISP_INVALID, "formal %d is not an atom", f);
+ arg = ao_lisp_poly_cons(arg->cdr);
+ f++;
+ }
+
+ lambda->type = AO_LISP_LAMBDA;
+ lambda->args = args;
+ lambda->code = ao_lisp_cons_poly(code);
+ lambda->frame = ao_lisp_frame_poly(ao_lisp_frame_current);
+ DBGI("build frame: "); DBG_POLY(lambda->frame); DBG("\n");
+ DBG_STACK();
+ return ao_lisp_lambda_poly(lambda);
+}
+
+ao_poly
+ao_lisp_lambda(struct ao_lisp_cons *cons)
+{
+ return ao_lisp_lambda_alloc(cons, AO_LISP_FUNC_LAMBDA);
+}
+
+ao_poly
+ao_lisp_lexpr(struct ao_lisp_cons *cons)
+{
+ return ao_lisp_lambda_alloc(cons, AO_LISP_FUNC_LEXPR);
+}
+
+ao_poly
+ao_lisp_nlambda(struct ao_lisp_cons *cons)
+{
+ return ao_lisp_lambda_alloc(cons, AO_LISP_FUNC_NLAMBDA);
+}
+
+ao_poly
+ao_lisp_macro(struct ao_lisp_cons *cons)
+{
+ return ao_lisp_lambda_alloc(cons, AO_LISP_FUNC_MACRO);
+}
+
+ao_poly
+ao_lisp_lambda_eval(struct ao_lisp_lambda *lambda,
+ struct ao_lisp_cons *cons)
+{
+ struct ao_lisp_cons *code;
+ struct ao_lisp_cons *args;
+ struct ao_lisp_frame *next_frame;
+ int args_wanted;
+ int args_provided;
+
+ code = ao_lisp_poly_cons(lambda->code);
+ DBGI("lambda "); DBG_POLY(ao_lisp_lambda_poly(lambda)); DBG("\n");
+ args = ao_lisp_poly_cons(ao_lisp_arg(code, 0));
+
+ args_wanted = ao_lisp_cons_length(args);
+
+ /* Create a frame to hold the variables
+ */
+ if (lambda->args == AO_LISP_FUNC_LAMBDA)
+ args_provided = ao_lisp_cons_length(cons) - 1;
+ else
+ args_provided = 1;
+ if (args_wanted != args_provided)
+ return ao_lisp_error(AO_LISP_INVALID, "need %d args, not %d", args_wanted, args_provided);
+ next_frame = ao_lisp_frame_new(args_wanted);
+ switch (lambda->args) {
+ case AO_LISP_FUNC_LAMBDA: {
+ int f;
+ struct ao_lisp_cons *vals = ao_lisp_poly_cons(cons->cdr);
+
+ for (f = 0; f < args_wanted; f++) {
+ DBGI("bind "); DBG_POLY(args->car); DBG(" = "); DBG_POLY(vals->car); DBG("\n");
+ next_frame->vals[f].atom = args->car;
+ next_frame->vals[f].val = vals->car;
+ args = ao_lisp_poly_cons(args->cdr);
+ vals = ao_lisp_poly_cons(vals->cdr);
+ }
+ break;
+ }
+ case AO_LISP_FUNC_LEXPR:
+ case AO_LISP_FUNC_NLAMBDA:
+ case AO_LISP_FUNC_MACRO:
+ DBGI("bind "); DBG_POLY(args->car); DBG(" = "); DBG_POLY(cons->cdr); DBG("\n");
+ next_frame->vals[0].atom = args->car;
+ next_frame->vals[0].val = cons->cdr;
+ break;
+ }
+ next_frame->next = lambda->frame;
+ DBGI("eval frame: "); DBG_POLY(ao_lisp_frame_poly(next_frame)); DBG("\n");
+ ao_lisp_frame_current = next_frame;
+ ao_lisp_stack->frame = ao_lisp_frame_poly(ao_lisp_frame_current);
+ DBG_STACK();
+ return ao_lisp_arg(code, 1);
+}
projects / fw / altos / commitdiff