+++ /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_lisp.h"
-
-const struct ao_lisp_type ao_lisp_stack_type;
-
-static int
-stack_size(void *addr)
-{
- (void) addr;
- return sizeof (struct ao_lisp_stack);
-}
-
-static void
-stack_mark(void *addr)
-{
- struct ao_lisp_stack *stack = addr;
- for (;;) {
- ao_lisp_poly_mark(stack->sexprs, 0);
- ao_lisp_poly_mark(stack->values, 0);
- /* no need to mark values_tail */
- ao_lisp_poly_mark(stack->frame, 0);
- ao_lisp_poly_mark(stack->list, 0);
- stack = ao_lisp_poly_stack(stack->prev);
- if (ao_lisp_mark_memory(&ao_lisp_stack_type, stack))
- break;
- }
-}
-
-static void
-stack_move(void *addr)
-{
- struct ao_lisp_stack *stack = addr;
-
- while (stack) {
- struct ao_lisp_stack *prev;
- int ret;
- (void) ao_lisp_poly_move(&stack->sexprs, 0);
- (void) ao_lisp_poly_move(&stack->values, 0);
- (void) ao_lisp_poly_move(&stack->values_tail, 0);
- (void) ao_lisp_poly_move(&stack->frame, 0);
- (void) ao_lisp_poly_move(&stack->list, 0);
- prev = ao_lisp_poly_stack(stack->prev);
- if (!prev)
- break;
- ret = ao_lisp_move_memory(&ao_lisp_stack_type, (void **) &prev);
- if (prev != ao_lisp_poly_stack(stack->prev))
- stack->prev = ao_lisp_stack_poly(prev);
- if (ret)
- break;
- stack = prev;
- }
-}
-
-const struct ao_lisp_type ao_lisp_stack_type = {
- .size = stack_size,
- .mark = stack_mark,
- .move = stack_move,
- .name = "stack"
-};
-
-struct ao_lisp_stack *ao_lisp_stack_free_list;
-
-void
-ao_lisp_stack_reset(struct ao_lisp_stack *stack)
-{
- stack->state = eval_sexpr;
- stack->sexprs = AO_LISP_NIL;
- stack->values = AO_LISP_NIL;
- stack->values_tail = AO_LISP_NIL;
-}
-
-static struct ao_lisp_stack *
-ao_lisp_stack_new(void)
-{
- struct ao_lisp_stack *stack;
-
- if (ao_lisp_stack_free_list) {
- stack = ao_lisp_stack_free_list;
- ao_lisp_stack_free_list = ao_lisp_poly_stack(stack->prev);
- } else {
- stack = ao_lisp_alloc(sizeof (struct ao_lisp_stack));
- if (!stack)
- return 0;
- stack->type = AO_LISP_STACK;
- }
- ao_lisp_stack_reset(stack);
- return stack;
-}
-
-int
-ao_lisp_stack_push(void)
-{
- struct ao_lisp_stack *stack;
-
- stack = ao_lisp_stack_new();
-
- if (!stack)
- return 0;
-
- stack->prev = ao_lisp_stack_poly(ao_lisp_stack);
- stack->frame = ao_lisp_frame_poly(ao_lisp_frame_current);
- stack->list = AO_LISP_NIL;
-
- ao_lisp_stack = stack;
-
- DBGI("stack push\n");
- DBG_FRAMES();
- DBG_IN();
- return 1;
-}
-
-void
-ao_lisp_stack_pop(void)
-{
- ao_poly prev;
- struct ao_lisp_frame *prev_frame;
-
- if (!ao_lisp_stack)
- return;
- prev = ao_lisp_stack->prev;
- if (!ao_lisp_stack_marked(ao_lisp_stack)) {
- ao_lisp_stack->prev = ao_lisp_stack_poly(ao_lisp_stack_free_list);
- ao_lisp_stack_free_list = ao_lisp_stack;
- }
-
- ao_lisp_stack = ao_lisp_poly_stack(prev);
- prev_frame = ao_lisp_frame_current;
- if (ao_lisp_stack)
- ao_lisp_frame_current = ao_lisp_poly_frame(ao_lisp_stack->frame);
- else
- ao_lisp_frame_current = NULL;
- if (ao_lisp_frame_current != prev_frame)
- ao_lisp_frame_free(prev_frame);
- DBG_OUT();
- DBGI("stack pop\n");
- DBG_FRAMES();
-}
-
-void
-ao_lisp_stack_clear(void)
-{
- ao_lisp_stack = NULL;
- ao_lisp_frame_current = NULL;
- ao_lisp_v = AO_LISP_NIL;
-}
-
-void
-ao_lisp_stack_write(ao_poly poly)
-{
- struct ao_lisp_stack *s = ao_lisp_poly_stack(poly);
-
- while (s) {
- if (s->type & AO_LISP_STACK_PRINT) {
- printf("[recurse...]");
- return;
- }
- s->type |= AO_LISP_STACK_PRINT;
- printf("\t[\n");
- printf("\t\texpr: "); ao_lisp_poly_write(s->list); printf("\n");
- printf("\t\tstate: %s\n", ao_lisp_state_names[s->state]);
- ao_lisp_error_poly ("values: ", s->values, s->values_tail);
- ao_lisp_error_poly ("sexprs: ", s->sexprs, AO_LISP_NIL);
- ao_lisp_error_frame(2, "frame: ", ao_lisp_poly_frame(s->frame));
- printf("\t]\n");
- s->type &= ~AO_LISP_STACK_PRINT;
- s = ao_lisp_poly_stack(s->prev);
- }
-}
-
-/*
- * Copy a stack, being careful to keep everybody referenced
- */
-static struct ao_lisp_stack *
-ao_lisp_stack_copy(struct ao_lisp_stack *old)
-{
- struct ao_lisp_stack *new = NULL;
- struct ao_lisp_stack *n, *prev = NULL;
-
- while (old) {
- ao_lisp_stack_stash(0, old);
- ao_lisp_stack_stash(1, new);
- ao_lisp_stack_stash(2, prev);
- n = ao_lisp_stack_new();
- prev = ao_lisp_stack_fetch(2);
- new = ao_lisp_stack_fetch(1);
- old = ao_lisp_stack_fetch(0);
- if (!n)
- return NULL;
-
- ao_lisp_stack_mark(old);
- ao_lisp_frame_mark(ao_lisp_poly_frame(old->frame));
- *n = *old;
-
- if (prev)
- prev->prev = ao_lisp_stack_poly(n);
- else
- new = n;
- prev = n;
-
- old = ao_lisp_poly_stack(old->prev);
- }
- return new;
-}
-
-/*
- * Evaluate a continuation invocation
- */
-ao_poly
-ao_lisp_stack_eval(void)
-{
- struct ao_lisp_stack *new = ao_lisp_stack_copy(ao_lisp_poly_stack(ao_lisp_v));
- if (!new)
- return AO_LISP_NIL;
-
- struct ao_lisp_cons *cons = ao_lisp_poly_cons(ao_lisp_stack->values);
-
- if (!cons || !cons->cdr)
- return ao_lisp_error(AO_LISP_INVALID, "continuation requires a value");
-
- new->state = eval_val;
-
- ao_lisp_stack = new;
- ao_lisp_frame_current = ao_lisp_poly_frame(ao_lisp_stack->frame);
-
- return ao_lisp_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_lisp_do_call_cc(struct ao_lisp_cons *cons)
-{
- struct ao_lisp_stack *new;
- ao_poly v;
-
- /* Make sure the single parameter is a lambda */
- if (!ao_lisp_check_argc(_ao_lisp_atom_call2fcc, cons, 1, 1))
- return AO_LISP_NIL;
- if (!ao_lisp_check_argt(_ao_lisp_atom_call2fcc, cons, 0, AO_LISP_LAMBDA, 0))
- return AO_LISP_NIL;
-
- /* go get the lambda */
- ao_lisp_v = ao_lisp_arg(cons, 0);
-
- /* Note that the whole call chain now has
- * a reference to it which may escape
- */
- new = ao_lisp_stack_copy(ao_lisp_stack);
- if (!new)
- return AO_LISP_NIL;
-
- /* re-fetch cons after the allocation */
- cons = ao_lisp_poly_cons(ao_lisp_poly_cons(ao_lisp_stack->values)->cdr);
-
- /* Reset the arg list to the current stack,
- * and call the lambda
- */
-
- cons->car = ao_lisp_stack_poly(new);
- cons->cdr = AO_LISP_NIL;
- v = ao_lisp_lambda_eval();
- ao_lisp_stack->sexprs = v;
- ao_lisp_stack->state = eval_begin;
- return AO_LISP_NIL;
-}
projects / fw / altos / blobdiff