altos/lisp: Clean up OS integration bits, add defun

Provide an abstraction for the OS interface so that it
can build more cleanly on Linux and AltOS. Add defun macro.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 188 insertions, 0 deletions

diff --git a/src/lisp/ao_lisp_lambda.c b/src/lisp/ao_lisp_lambda.c
new file mode 100644
index 00000000..cc5af4bc
--- /dev/null
+++ b/src/lisp/ao_lisp_lambda.c
@@ -0,0 +1,188 @@
+/*
+ * 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);
+}