+++ /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, either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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.
- */
-
-#include "ao_scheme.h"
-
-const struct ao_scheme_type ao_scheme_stack_type;
-
-static int
-stack_size(void *addr)
-{
- (void) addr;
- return sizeof (struct ao_scheme_stack);
-}
-
-static void
-stack_mark(void *addr)
-{
- struct ao_scheme_stack *stack = addr;
- for (;;) {
- ao_scheme_poly_mark(stack->sexprs, 0);
- ao_scheme_poly_mark(stack->values, 0);
- /* no need to mark values_tail */
- ao_scheme_poly_mark(stack->frame, 0);
- ao_scheme_poly_mark(stack->list, 0);
- stack = ao_scheme_poly_stack(stack->prev);
- if (ao_scheme_mark_memory(&ao_scheme_stack_type, stack))
- break;
- }
-}
-
-static void
-stack_move(void *addr)
-{
- struct ao_scheme_stack *stack = addr;
-
- while (stack) {
- struct ao_scheme_stack *prev;
- int ret;
- (void) ao_scheme_poly_move(&stack->sexprs, 0);
- (void) ao_scheme_poly_move(&stack->values, 0);
- (void) ao_scheme_poly_move(&stack->values_tail, 0);
- (void) ao_scheme_poly_move(&stack->frame, 0);
- (void) ao_scheme_poly_move(&stack->list, 0);
- prev = ao_scheme_poly_stack(stack->prev);
- if (!prev)
- break;
- ret = ao_scheme_move_memory(&ao_scheme_stack_type, (void **) &prev);
- if (prev != ao_scheme_poly_stack(stack->prev))
- stack->prev = ao_scheme_stack_poly(prev);
- if (ret)
- break;
- stack = prev;
- }
-}
-
-const struct ao_scheme_type ao_scheme_stack_type = {
- .size = stack_size,
- .mark = stack_mark,
- .move = stack_move,
- .name = "stack"
-};
-
-struct ao_scheme_stack *ao_scheme_stack_free_list;
-
-void
-ao_scheme_stack_reset(struct ao_scheme_stack *stack)
-{
- stack->state = eval_sexpr;
- stack->sexprs = AO_SCHEME_NIL;
- stack->values = AO_SCHEME_NIL;
- stack->values_tail = AO_SCHEME_NIL;
-}
-
-static struct ao_scheme_stack *
-ao_scheme_stack_new(void)
-{
- struct ao_scheme_stack *stack;
-
- if (ao_scheme_stack_free_list) {
- stack = ao_scheme_stack_free_list;
- ao_scheme_stack_free_list = ao_scheme_poly_stack(stack->prev);
- } else {
- stack = ao_scheme_alloc(sizeof (struct ao_scheme_stack));
- if (!stack)
- return 0;
- stack->type = AO_SCHEME_STACK;
- }
- ao_scheme_stack_reset(stack);
- return stack;
-}
-
-int
-ao_scheme_stack_push(void)
-{
- struct ao_scheme_stack *stack;
-
- stack = ao_scheme_stack_new();
-
- if (!stack)
- return 0;
-
- stack->prev = ao_scheme_stack_poly(ao_scheme_stack);
- stack->frame = ao_scheme_frame_poly(ao_scheme_frame_current);
- stack->list = AO_SCHEME_NIL;
-
- ao_scheme_stack = stack;
-
- DBGI("stack push\n");
- DBG_FRAMES();
- DBG_IN();
- return 1;
-}
-
-void
-ao_scheme_stack_pop(void)
-{
- ao_poly prev;
- struct ao_scheme_frame *prev_frame;
-
- if (!ao_scheme_stack)
- return;
- prev = ao_scheme_stack->prev;
- if (!ao_scheme_stack_marked(ao_scheme_stack)) {
- ao_scheme_stack->prev = ao_scheme_stack_poly(ao_scheme_stack_free_list);
- ao_scheme_stack_free_list = ao_scheme_stack;
- }
-
- ao_scheme_stack = ao_scheme_poly_stack(prev);
- prev_frame = ao_scheme_frame_current;
- if (ao_scheme_stack)
- ao_scheme_frame_current = ao_scheme_poly_frame(ao_scheme_stack->frame);
- else
- ao_scheme_frame_current = NULL;
- if (ao_scheme_frame_current != prev_frame)
- ao_scheme_frame_free(prev_frame);
- DBG_OUT();
- DBGI("stack pop\n");
- DBG_FRAMES();
-}
-
-void
-ao_scheme_stack_clear(void)
-{
- ao_scheme_stack = NULL;
- ao_scheme_frame_current = NULL;
- ao_scheme_v = AO_SCHEME_NIL;
-}
-
-void
-ao_scheme_stack_write(ao_poly poly, bool write)
-{
- struct ao_scheme_stack *s = ao_scheme_poly_stack(poly);
- struct ao_scheme_stack *clear = s;
- int written = 0;
-
- (void) write;
- ao_scheme_print_start();
- ao_scheme_frame_print_indent += 2;
- while (s) {
- if (ao_scheme_print_mark_addr(s)) {
- printf("[recurse...]");
- break;
- }
- written++;
- printf("\t[\n");
- ao_scheme_printf("\t\texpr: %v\n", s->list);
- ao_scheme_printf("\t\tvalues: %v\n", s->values);
- ao_scheme_printf("\t\tframe: %v\n", s->frame);
- printf("\t]\n");
- s = ao_scheme_poly_stack(s->prev);
- }
- ao_scheme_frame_print_indent -= 2;
- if (ao_scheme_print_stop()) {
- while (written--) {
- ao_scheme_print_clear_addr(clear);
- clear = ao_scheme_poly_stack(clear->prev);
- }
- }
-}
-
-/*
- * Copy a stack, being careful to keep everybody referenced
- */
-static struct ao_scheme_stack *
-ao_scheme_stack_copy(struct ao_scheme_stack *old)
-{
- struct ao_scheme_stack *new = NULL;
- struct ao_scheme_stack *n, *prev = NULL;
-
- while (old) {
- ao_scheme_stack_stash(old);
- ao_scheme_stack_stash(new);
- ao_scheme_stack_stash(prev);
- n = ao_scheme_stack_new();
- prev = ao_scheme_stack_fetch();
- new = ao_scheme_stack_fetch();
- old = ao_scheme_stack_fetch();
- if (!n)
- return NULL;
-
- ao_scheme_stack_mark(old);
- ao_scheme_frame_mark(ao_scheme_poly_frame(old->frame));
- *n = *old;
-
- if (prev)
- prev->prev = ao_scheme_stack_poly(n);
- else
- new = n;
- prev = n;
-
- old = ao_scheme_poly_stack(old->prev);
- }
- return new;
-}
-
-/*
- * Evaluate a continuation invocation
- */
-ao_poly
-ao_scheme_stack_eval(void)
-{
- struct ao_scheme_cons *cons;
- struct ao_scheme_stack *new = ao_scheme_stack_copy(ao_scheme_poly_stack(ao_scheme_v));
- if (!new)
- return AO_SCHEME_NIL;
-
- cons = ao_scheme_poly_cons(ao_scheme_stack->values);
-
- if (!cons || !cons->cdr)
- return ao_scheme_error(AO_SCHEME_INVALID, "continuation requires a value");
-
- new->state = eval_val;
-
- ao_scheme_stack = new;
- ao_scheme_frame_current = ao_scheme_poly_frame(ao_scheme_stack->frame);
-
- return ao_scheme_poly_cons(cons->cdr)->car;
-}
-
-/*
- * Call with current continuation. This calls a lambda, passing
- * it a single argument which is the current continuation
- */
-ao_poly
-ao_scheme_do_call_cc(struct ao_scheme_cons *cons)
-{
- struct ao_scheme_stack *new;
- ao_poly v;
-
- /* Make sure the single parameter is a lambda */
- if (!ao_scheme_check_argc(_ao_scheme_atom_call2fcc, cons, 1, 1))
- return AO_SCHEME_NIL;
- if (!ao_scheme_check_argt(_ao_scheme_atom_call2fcc, cons, 0, AO_SCHEME_LAMBDA, 0))
- return AO_SCHEME_NIL;
-
- /* go get the lambda */
- ao_scheme_v = ao_scheme_arg(cons, 0);
-
- /* Note that the whole call chain now has
- * a reference to it which may escape
- */
- new = ao_scheme_stack_copy(ao_scheme_stack);
- if (!new)
- return AO_SCHEME_NIL;
-
- /* re-fetch cons after the allocation */
- cons = ao_scheme_poly_cons(ao_scheme_poly_cons(ao_scheme_stack->values)->cdr);
-
- /* Reset the arg list to the current stack,
- * and call the lambda
- */
-
- cons->car = ao_scheme_stack_poly(new);
- cons->cdr = AO_SCHEME_NIL;
- v = ao_scheme_lambda_eval();
- ao_scheme_stack->sexprs = v;
- ao_scheme_stack->state = eval_begin;
- return AO_SCHEME_NIL;
-}
projects / fw / altos / blobdiff