+++ /dev/null
-/*
- * 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
-lambda_size(void *addr)
-{
- (void) addr;
- return sizeof (struct ao_scheme_lambda);
-}
-
-static void
-lambda_mark(void *addr)
-{
- struct ao_scheme_lambda *lambda = addr;
-
- ao_scheme_poly_mark(lambda->code, 0);
- ao_scheme_poly_mark(lambda->frame, 0);
-}
-
-static void
-lambda_move(void *addr)
-{
- struct ao_scheme_lambda *lambda = addr;
-
- ao_scheme_poly_move(&lambda->code, 0);
- ao_scheme_poly_move(&lambda->frame, 0);
-}
-
-const struct ao_scheme_type ao_scheme_lambda_type = {
- .size = lambda_size,
- .mark = lambda_mark,
- .move = lambda_move,
- .name = "lambda",
-};
-
-void
-ao_scheme_lambda_write(FILE *out, ao_poly poly, bool write)
-{
- struct ao_scheme_lambda *lambda = ao_scheme_poly_lambda(poly);
- struct ao_scheme_cons *cons = ao_scheme_poly_cons(lambda->code);
-
- putc('(', out);
- fputs(ao_scheme_args_name(lambda->args), out);
- while (cons) {
- putc(' ', out);
- ao_scheme_poly_write(out, cons->car, write);
- cons = ao_scheme_poly_cons(cons->cdr);
- }
- putc(')', out);
-}
-
-static ao_poly
-ao_scheme_lambda_alloc(struct ao_scheme_cons *code, int args)
-{
- struct ao_scheme_lambda *lambda;
- ao_poly formal;
- struct ao_scheme_cons *cons;
-
- formal = ao_scheme_arg(code, 0);
- while (formal != AO_SCHEME_NIL) {
- switch (ao_scheme_poly_type(formal)) {
- case AO_SCHEME_CONS:
- cons = ao_scheme_poly_cons(formal);
- if (ao_scheme_poly_type(cons->car) != AO_SCHEME_ATOM)
- return ao_scheme_error(AO_SCHEME_INVALID, "formal %p is not atom", cons->car);
- formal = cons->cdr;
- break;
- case AO_SCHEME_ATOM:
- formal = AO_SCHEME_NIL;
- break;
- default:
- return ao_scheme_error(AO_SCHEME_INVALID, "formal %p is not atom", formal);
- }
- }
-
- ao_scheme_cons_stash(code);
- lambda = ao_scheme_alloc(sizeof (struct ao_scheme_lambda));
- code = ao_scheme_cons_fetch();
- if (!lambda)
- return AO_SCHEME_NIL;
-
- lambda->type = AO_SCHEME_LAMBDA;
- lambda->args = args;
- lambda->code = ao_scheme_cons_poly(code);
- lambda->frame = ao_scheme_frame_mark(ao_scheme_frame_current);
- DBGI("build frame: "); DBG_POLY(lambda->frame); DBG("\n");
- DBG_STACK();
- return ao_scheme_lambda_poly(lambda);
-}
-
-ao_poly
-ao_scheme_do_lambda(struct ao_scheme_cons *cons)
-{
- return ao_scheme_lambda_alloc(cons, AO_SCHEME_FUNC_LAMBDA);
-}
-
-ao_poly
-ao_scheme_do_nlambda(struct ao_scheme_cons *cons)
-{
- return ao_scheme_lambda_alloc(cons, AO_SCHEME_FUNC_NLAMBDA);
-}
-
-ao_poly
-ao_scheme_do_macro(struct ao_scheme_cons *cons)
-{
- return ao_scheme_lambda_alloc(cons, AO_SCHEME_FUNC_MACRO);
-}
-
-ao_poly
-ao_scheme_lambda_eval(void)
-{
- struct ao_scheme_lambda *lambda = ao_scheme_poly_lambda(ao_scheme_v);
- struct ao_scheme_cons *cons = ao_scheme_poly_cons(ao_scheme_stack->values);
- struct ao_scheme_cons *code = ao_scheme_poly_cons(lambda->code);
- ao_poly formals;
- struct ao_scheme_frame *next_frame;
- int args_wanted;
- ao_poly varargs = AO_SCHEME_NIL;
- int args_provided;
- int f;
- struct ao_scheme_cons *vals;
-
- DBGI("lambda "); DBG_POLY(ao_scheme_lambda_poly(lambda)); DBG("\n");
-
- args_wanted = 0;
- for (formals = ao_scheme_arg(code, 0);
- ao_scheme_is_pair(formals);
- formals = ao_scheme_poly_cons(formals)->cdr)
- ++args_wanted;
- if (formals != AO_SCHEME_NIL) {
- if (ao_scheme_poly_type(formals) != AO_SCHEME_ATOM)
- return ao_scheme_error(AO_SCHEME_INVALID, "bad lambda form");
- varargs = formals;
- }
-
- /* Create a frame to hold the variables
- */
- args_provided = ao_scheme_cons_length(cons) - 1;
- if (varargs == AO_SCHEME_NIL) {
- if (args_wanted != args_provided)
- return ao_scheme_error(AO_SCHEME_INVALID, "need %d args, got %d", args_wanted, args_provided);
- } else {
- if (args_provided < args_wanted)
- return ao_scheme_error(AO_SCHEME_INVALID, "need at least %d args, got %d", args_wanted, args_provided);
- }
-
- ao_scheme_poly_stash(varargs);
- next_frame = ao_scheme_frame_new(args_wanted + (varargs != AO_SCHEME_NIL));
- varargs = ao_scheme_poly_fetch();
- if (!next_frame)
- return AO_SCHEME_NIL;
-
- /* Re-fetch all of the values in case something moved */
- lambda = ao_scheme_poly_lambda(ao_scheme_v);
- cons = ao_scheme_poly_cons(ao_scheme_stack->values);
- code = ao_scheme_poly_cons(lambda->code);
- formals = ao_scheme_arg(code, 0);
- vals = ao_scheme_poly_cons(cons->cdr);
-
- next_frame->prev = lambda->frame;
- ao_scheme_frame_current = next_frame;
- ao_scheme_stack->frame = ao_scheme_frame_poly(ao_scheme_frame_current);
-
- for (f = 0; f < args_wanted; f++) {
- struct ao_scheme_cons *arg = ao_scheme_poly_cons(formals);
- DBGI("bind "); DBG_POLY(arg->car); DBG(" = "); DBG_POLY(vals->car); DBG("\n");
- ao_scheme_frame_bind(next_frame, f, arg->car, vals->car);
- formals = arg->cdr;
- vals = ao_scheme_poly_cons(vals->cdr);
- }
- if (varargs) {
- DBGI("bind "); DBG_POLY(varargs); DBG(" = "); DBG_POLY(ao_scheme_cons_poly(vals)); DBG("\n");
- /*
- * Bind the rest of the arguments to the final parameter
- */
- ao_scheme_frame_bind(next_frame, f, varargs, ao_scheme_cons_poly(vals));
- } else {
- /*
- * Mark the cons cells from the actuals as freed for immediate re-use, unless
- * the actuals point into the source function (nlambdas and macros), or if the
- * stack containing them was copied as a part of a continuation
- */
- if (lambda->args == AO_SCHEME_FUNC_LAMBDA && !ao_scheme_stack_marked(ao_scheme_stack)) {
- ao_scheme_stack->values = AO_SCHEME_NIL;
- ao_scheme_cons_free(cons);
- }
- }
- DBGI("eval frame: "); DBG_POLY(ao_scheme_frame_poly(next_frame)); DBG("\n");
- DBG_STACK();
- DBGI("eval code: "); DBG_POLY(code->cdr); DBG("\n");
- return code->cdr;
-}
projects / fw / altos / blobdiff