/* -*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*- */
/* vim: set filetype=c tabstop=8 shiftwidth=4 expandtab: */

/*
    list.d -- List manipulating routines.
*/
/*
    Copyright (c) 1984, Taiichi Yuasa and Masami Hagiya.
    Copyright (c) 1990, Giuseppe Attardi.
    Copyright (c) 2001, Juan Jose Garcia Ripoll.

    ECL is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    See file '../Copyright' for full details.
*/

#include <ecl/ecl.h>
#include <ecl/ecl-inl.h>

struct cl_test {
        bool (*test_c_function)(struct cl_test *, cl_object);
        cl_object (*key_c_function)(struct cl_test *, cl_object);
        cl_env_ptr env;
        cl_object key_function;
        cl_objectfn key_fn;
        cl_object test_function;
        cl_objectfn test_fn;
        cl_object item_compared;
};

static cl_object subst(struct cl_test *t, cl_object new_obj, cl_object tree);
static cl_object nsubst(struct cl_test *t, cl_object new_obj, cl_object tree);
static cl_object sublis(struct cl_test *t, cl_object alist, cl_object tree);
static cl_object nsublis(struct cl_test *t, cl_object alist, cl_object tree);
static cl_object do_assoc(struct cl_test *t, cl_object alist);

#define TEST(t,k) ((t)->test_c_function)((t),(k))
#define KEY(t,x) ((t)->key_c_function)((t),(x))
#define close_test(t) (void)0

static bool
test_compare(struct cl_test *t, cl_object x)
{
        x = KEY(t,x);
        t->env->function = t->test_function;
        return t->test_fn(2, t->item_compared, x) != ECL_NIL;
}

static bool
test_compare_not(struct cl_test *t, cl_object x)
{
        x = KEY(t,x);
        t->env->function = t->test_function;
        return t->test_fn(2, t->item_compared, x) == ECL_NIL;
}

static bool
test_eq(struct cl_test *t, cl_object x)
{
        return (t->item_compared == KEY(t,x));
}

static bool
test_eql(struct cl_test *t, cl_object x)
{
        return ecl_eql(t->item_compared, KEY(t,x));
}

static bool
test_equal(struct cl_test *t, cl_object x)
{
        return ecl_equal(t->item_compared, KEY(t,x));
}

static bool
test_equalp(struct cl_test *t, cl_object x)
{
        return ecl_equalp(t->item_compared, KEY(t,x));
}

static cl_object
key_function(struct cl_test *t, cl_object x)
{
        t->env->function = t->key_function;
        return t->key_fn(1,x);
}

static cl_object
key_identity(struct cl_test *t, cl_object x)
{
        return x;
}

static void
setup_test(struct cl_test *t, cl_object item, cl_object test,
           cl_object test_not, cl_object key)
{
        cl_env_ptr env = t->env = ecl_process_env();
        t->item_compared = item;
        if (test != ECL_NIL) {
                if (test_not != ECL_NIL)
                    FEerror("Both :TEST and :TEST-NOT are specified.", 0);
                t->test_function = test = si_coerce_to_function(test);
                if (test == ECL_SYM_FUN(@'eq')) {
                        t->test_c_function = test_eq;
                } else if (test == ECL_SYM_FUN(@'eql')) {
                        t->test_c_function = test_eql;
                } else if (test == ECL_SYM_FUN(@'equal')) {
                        t->test_c_function = test_equal;
                } else if (test == ECL_SYM_FUN(@'equalp')) {
                        t->test_c_function = test_equalp;
                } else {
                        t->test_c_function = test_compare;
                        t->test_fn = ecl_function_dispatch(env, test);
                        t->test_function = env->function;
                }
        } else if (test_not != ECL_NIL) {
                t->test_c_function = test_compare_not;
                test_not = si_coerce_to_function(test_not);
                t->test_fn = ecl_function_dispatch(env, test_not);
                t->test_function = env->function;
        } else {
                t->test_c_function = test_eql;
        }
        if (key != ECL_NIL) {
                key = si_coerce_to_function(key);
                t->key_fn = ecl_function_dispatch(env, key);
                t->key_function = env->function;
                t->key_c_function = key_function;
        } else {
                t->key_c_function = key_identity;
        }
}

@(defun list (&rest args)
        cl_object head = ECL_NIL;
@
        if (narg--) {
                cl_object tail = head = ecl_list1(ecl_va_arg(args));
                while (narg--) {
                        cl_object cons = ecl_list1(ecl_va_arg(args));
                        ECL_RPLACD(tail, cons);
                        tail = cons;
                }
        }
        @(return head)
@)

@(defun list* (&rest args)
        cl_object head;
@
        if (narg == 0)
                FEwrong_num_arguments(@[list*]);
        head = ecl_va_arg(args);
        if (--narg) {
                cl_object tail = head = ecl_list1(head);
                while (--narg) {
                        cl_object cons = ecl_list1(ecl_va_arg(args));
                        ECL_RPLACD(tail, cons);
                        tail = cons;
                }
                ECL_RPLACD(tail, ecl_va_arg(args));
        }
        @(return head)
@)

static cl_object *
append_into(cl_object head, cl_object *tail, cl_object l)
{
        if (!Null(*tail)) {
                /* (APPEND '(1 . 2) 3) */
                FEtype_error_proper_list(head);
        }
        while (CONSP(l)) {
                cl_object cons = ecl_list1(ECL_CONS_CAR(l));
                *tail = cons;
                tail = &ECL_CONS_CDR(cons);
                l = ECL_CONS_CDR(l);
        }
        *tail = l;
        return tail;
}

@(defun append (&rest rest)
        cl_object head = ECL_NIL, *tail = &head;
@
        for (; narg > 1; narg--) {
                cl_object other = ecl_va_arg(rest);
                tail = append_into(head, tail, other);
        }
        if (narg) {
                if (!Null(*tail)) {
                        /* (APPEND '(1 . 2) 3) */
                        FEtype_error_proper_list(head);
                }
                *tail = ecl_va_arg(rest);
        }
        @(return head)
@)

cl_object
ecl_append(cl_object x, cl_object y)
{
        cl_object head = ECL_NIL;
        cl_object *tail = &head;
        if (!Null(x)) {
                tail = append_into(head, tail, x);
        }
        if (!Null(*tail)) {
                /* (APPEND '(1 . 2) 3) */
                FEtype_error_proper_list(head);
        }
        *tail = y;
        return head;
}

#define LENTH(n) (cl_object x) {                                \
                const cl_env_ptr the_env = ecl_process_env();   \
                ecl_return1(the_env, ecl_nth(n, x));            \
        }
cl_object @fifth        LENTH(4)
cl_object @sixth        LENTH(5)
cl_object @seventh      LENTH(6)
cl_object @eighth       LENTH(7)
cl_object @ninth        LENTH(8)
cl_object @tenth        LENTH(9)
#undef LENTH

static bool
tree_equal(struct cl_test *t, cl_object x, cl_object y)
{
BEGIN:
        if (CONSP(x)) {
                if (CONSP(y)) {
                        if (tree_equal(t, ECL_CONS_CAR(x), ECL_CONS_CAR(y))) {
                                x = ECL_CONS_CDR(x);
                                y = ECL_CONS_CDR(y);
                                goto BEGIN;
                        } else {
                                return(FALSE);
                        }
                } else {
                        return(FALSE);
                }
        } else {
                t->item_compared = x;
                if (TEST(t, y))
                        return(TRUE);
                else
                        return(FALSE);
        }
}

@(defun tree_equal (x y &key test test_not)
        struct cl_test t;
        cl_object output;
@
        setup_test(&t, ECL_NIL, test, test_not, ECL_NIL);
        output = tree_equal(&t, x, y)? ECL_T : ECL_NIL;
        close_test(&t);
        @(return output)
@)

cl_object
cl_endp(cl_object x)
{
        cl_object output = ECL_NIL;
        if (Null(x)) {
                output = ECL_T;
        } else if (ecl_unlikely(!LISTP(x))) {
                FEwrong_type_only_arg(@[endp], x, @[list]);
        }
        @(return output);
}

bool
ecl_endp(cl_object x)
{
        if (Null(x)) {
                return TRUE;
        } else if (ecl_unlikely(!LISTP(x))) {
                FEwrong_type_only_arg(@[endp], x, @[list]);
        }
        return FALSE;
}

cl_object
cl_list_length(cl_object x)
{
        cl_fixnum n;
        cl_object fast, slow;
        /* INV: A list's length always fits in a fixnum */
        fast = slow = x;
        for (n = 0; !Null(fast); n++, fast = ECL_CONS_CDR(fast)) {
                if (ecl_unlikely(!LISTP(fast))) {
                        FEtype_error_list(fast);
                }
                if (n & 1) {
                        /* Circular list? */
                        if (slow == fast) @(return ECL_NIL);
                        slow = ECL_CONS_CDR(slow);
                }
        }
        @(return ecl_make_fixnum(n));
}

cl_object
si_proper_list_p(cl_object x)
{
        cl_fixnum n;
        cl_object fast, slow, test = ECL_T;
        /* INV: A list's length always fits in a fixnum */
        fast = slow = x;
        for (n = 0; !Null(fast); n++, fast = ECL_CONS_CDR(fast)) {
                if (!LISTP(fast)) {
                        test = ECL_NIL;
                        break;
                }
                if (n & 1) {
                        /* Circular list? */
                        if (slow == fast) {
                                test = ECL_NIL;
                                break;
                        }
                        slow = ECL_CONS_CDR(slow);
                }
        }
        @(return test);
}

cl_object
cl_nth(cl_object n, cl_object x)
{
        @(return ecl_nth(ecl_to_size(n), x))
}

cl_object
ecl_nth(cl_fixnum n, cl_object x)
{
        if (n < 0)
                FEtype_error_index(x, n);
        /* INV: No need to check for circularity since we visit
           at most `n' conses */
        for (; n > 0 && CONSP(x); n--)
                x = ECL_CONS_CDR(x);
        if (Null(x))
                return ECL_NIL;
        if (!LISTP(x))
                FEtype_error_list(x);
        return ECL_CONS_CAR(x);
}

cl_object
cl_nthcdr(cl_object n, cl_object x)
{
        @(return ecl_nthcdr(ecl_to_size(n), x))
}

cl_object
ecl_nthcdr(cl_fixnum n, cl_object x)
{
        if (n < 0)
                FEtype_error_index(x, n);
        while (n-- > 0 && !Null(x)) {
                if (LISTP(x)) {
                        x = ECL_CONS_CDR(x);
                } else {
                        FEtype_error_list(x);
                }
        }
        return x;
}

cl_object
ecl_last(cl_object l, cl_index n)
{
        /* The algorithm is very simple. We run over the list with
         * two pointers, "l" and "r". The separation between both
         * must be "n", so that when "l" finds no more conses, "r"
         * contains the output. */
        cl_object r;
        for (r = l; n && CONSP(r); n--, r = ECL_CONS_CDR(r))
                ;
        /* If "l" has not moved, we have to ensure that it is a list */
        if (r == l) {
                if (!LISTP(r)) FEtype_error_list(l);
                while (CONSP(r)) {
                        r = ECL_CONS_CDR(r);
                }
                return r;
        } else if (n == 0) {
                while (CONSP(r)) {
                        r = ECL_CONS_CDR(r);
                        l = ECL_CONS_CDR(l);
                }
                return l;
        } else {
                return l;
        }
}

@(defun last (l &optional (k ecl_make_fixnum(1)))
@
        if (ecl_t_of(k) == t_bignum)
                @(return l)
        @(return ecl_last(l, ecl_to_size(k)))
@)

@(defun make_list (size &key initial_element &aux x)
        cl_fixnum i;
@
        /* INV: ecl_to_size() signals a type-error if SIZE is not a integer >=0 */
        i = ecl_to_size(size);
        while (i-- > 0)
                x = CONS(initial_element, x);
        @(return x)
@)

cl_object
cl_copy_list(cl_object x)
{
        cl_object copy;
        if (ecl_unlikely(!LISTP(x))) {
                FEwrong_type_only_arg(@[copy-list], x, @[list]);
        }
        copy = ECL_NIL;
        if (!Null(x)) {
                cl_object tail = copy = ecl_list1(CAR(x));
                while (x = ECL_CONS_CDR(x), CONSP(x)) {
                        cl_object cons = ecl_list1(ECL_CONS_CAR(x));
                        ECL_RPLACD(tail, cons);
                        tail = cons;
                }
                ECL_RPLACD(tail, x);
        }
        @(return copy);
}

static cl_object
duplicate_pairs(cl_object x)
{
        cl_object p = ECL_CONS_CAR(x);
        if (CONSP(p))
                p = CONS(ECL_CONS_CAR(p), ECL_CONS_CDR(p));
        return ecl_list1(p);
}

cl_object
cl_copy_alist(cl_object x)
{
        cl_object copy;
        if (ecl_unlikely(!LISTP(x))) {
                FEwrong_type_only_arg(@[copy-alist], x, @[list]);
        }
        copy = ECL_NIL;
        if (!Null(x)) {
                cl_object tail = copy = duplicate_pairs(x);
                while (x = ECL_CONS_CDR(x), !Null(x)) {
                        if (!LISTP(x)) {
                                FEtype_error_list(x);
                        } else {
                                cl_object cons = duplicate_pairs(x);
                                tail = ECL_RPLACD(tail, cons);
                                tail = cons;
                        }
                }
        }
        @(return copy);
}

static cl_object
do_copy_tree(cl_object x)
{
        if (CONSP(x)) {
                x = CONS(do_copy_tree(ECL_CONS_CAR(x)),
                         do_copy_tree(ECL_CONS_CDR(x)));
        }
        return x;
}

cl_object
cl_copy_tree(cl_object x)
{
        @(return do_copy_tree(x))
}

cl_object
cl_revappend(cl_object x, cl_object y)
{
        loop_for_in(x) {
                y = CONS(ECL_CONS_CAR(x),y);
        } end_loop_for_in;
        @(return y)
}

@(defun nconc (&rest lists)
        cl_object head = ECL_NIL, tail = ECL_NIL;
@       
        while (narg--) {
                cl_object new_tail, other = ecl_va_arg(lists);
                if (Null(other)) {
                        new_tail = tail;
                } else if (CONSP(other)) {
                        new_tail = ecl_last(other, 1);
                } else {
                        if (narg) FEtype_error_list(other);
                        new_tail = tail;
                }
                if (Null(head)) {
                        head = other;
                } else {
                        ECL_RPLACD(tail, other);
                }
                tail = new_tail;
        }
        @(return head)
@)

cl_object
ecl_nconc(cl_object l, cl_object y)
{
        if (Null(l)) {
                return y;
        } else {
                ECL_RPLACD(ecl_last(l, 1), y);
                return l;
        }
}

cl_object
cl_nreconc(cl_object l, cl_object y)
{
        cl_object x, z;
        /* INV: when a circular list is "reconc'ed", the pointer ends
           up at the beginning of the original list, hence we need no
           slow pointer */
        for (x = l; !Null(x); ) {
                if (!LISTP(x)) FEtype_error_list(x);
                z = x;
                x = ECL_CONS_CDR(x);
                if (x == l) FEcircular_list(l);
                ECL_RPLACD(z, y);
                y = z;
        }
        @(return y)
}

cl_object
ecl_butlast(cl_object l, cl_index n)
{
        /* See LAST for details on this algorithm */
        cl_object r;
        for (r = l; n && CONSP(r); n--, r = ECL_CONS_CDR(r))
                ;
        if (Null(r)) {
                return ECL_NIL;
        } else if (!LISTP(r)) {
                /* We reach here either because l is shorter than n conses,
                 * or because it is not a list */
                if (r == l) FEtype_error_list(r);
                return ECL_NIL;
        } else {
                /* We reach here because l has at least n conses and
                 * thus we can take CAR(l) */
                cl_object head, tail;
                head = tail = ecl_list1(CAR(l));
                while (l = ECL_CONS_CDR(l), r = ECL_CONS_CDR(r), CONSP(r)) {
                        cl_object cons = ecl_list1(ECL_CONS_CAR(l));
                        ECL_RPLACD(tail, cons);
                        tail = cons;
                }
                return head;
        }
}

@(defun butlast (lis &optional (nn ecl_make_fixnum(1)))
@
        /* INV: No list has more than MOST_POSITIVE_FIXNUM elements */
        if (ecl_t_of(nn) == t_bignum)
                @(return ECL_NIL);
        /* INV: ecl_to_size() signals a type-error if NN is not an integer >=0 */
        @(return ecl_butlast(lis, ecl_to_size(nn)))
@)

cl_object
ecl_nbutlast(cl_object l, cl_index n)
{
        cl_object r;
        if (ecl_unlikely(!LISTP(l)))
                FEwrong_type_only_arg(@[nbutlast], l, @[list]);
        for (n++, r = l; n && CONSP(r); n--, r = ECL_CONS_CDR(r))
                ;
        if (n == 0) {
                cl_object tail = l;
                while (CONSP(r)) {
                        tail = ECL_CONS_CDR(tail);
                        r = ECL_CONS_CDR(r);
                }
                ECL_RPLACD(tail, ECL_NIL);
                return l;
        }
        return ECL_NIL;
}

@(defun nbutlast (lis &optional (nn ecl_make_fixnum(1)))
@
        /* INV: No list has more than MOST_POSITIVE_FIXNUM elements */
        if (ecl_t_of(nn) == t_bignum)
                @(return ECL_NIL)
        /* INV: ecl_to_size() signas a type-error if NN is not an integer >=0 */
        @(return ecl_nbutlast(lis, ecl_to_size(nn)))
@)

cl_object
cl_ldiff(cl_object x, cl_object y)
{
        cl_object head = ECL_NIL;
        if (ecl_unlikely(!LISTP(x))) {
                FEwrong_type_only_arg(@[ldiff], x, @[list]);
        }
        /* Here we use that, if X or Y are CONS, then (EQL X Y)
         * only when X == Y */
        if (!Null(x) && (x != y)) {
                cl_object tail = head = ecl_list1(ECL_CONS_CAR(x));
                while (1) {
                        x = ECL_CONS_CDR(x);
                        if (!CONSP(x)) {
                                if (!ecl_eql(x, y)) {
                                        ECL_RPLACD(tail, x);
                                }
                                break;
                        } else if (x == y) {
                                break;
                        } else {
                                cl_object cons = ecl_list1(ECL_CONS_CAR(x));
                                ECL_RPLACD(tail, cons);
                                tail = cons;
                        }
                }
        }
        @(return head)
}

cl_object
cl_rplaca(cl_object x, cl_object v)
{
        if (ecl_unlikely(!CONSP(x)))
                FEwrong_type_nth_arg(@[rplaca], 1, x, @[cons]);
        ECL_RPLACA(x, v);
        @(return x)
}

cl_object
cl_rplacd(cl_object x, cl_object v)
{
        if (ecl_unlikely(!CONSP(x)))
                FEwrong_type_nth_arg(@[rplacd], 1, x, @[cons]);
        ECL_RPLACD(x, v);
        @(return x)
}

@(defun subst (new_obj old_obj tree &key test test_not key)
        struct cl_test t;
        cl_object output;
@
        setup_test(&t, old_obj, test, test_not, key);
        output = subst(&t, new_obj, tree);
        close_test(&t);
        @(return output)
@)


static cl_object
subst(struct cl_test *t, cl_object new_obj, cl_object tree)
{
        if (TEST(t, tree)) {
                return new_obj;
        } else if (ECL_ATOM(tree)) {
                return tree;
        } else {
                cl_object head, tail = ECL_NIL;
                do {
                        cl_object cons = subst(t, new_obj, ECL_CONS_CAR(tree));
                        cons = ecl_cons(cons, tree = ECL_CONS_CDR(tree));
                        if (Null(tail)) {
                                head = cons;
                        } else {
                                ECL_RPLACD(tail, cons);
                        }
                        tail = cons;
                        if (TEST(t, tree)) {
                                ECL_RPLACD(tail, new_obj);
                                return head;
                        }
                } while (CONSP(tree));
                return head;
        }
}

@(defun nsubst (new_obj old_obj tree &key test test_not key)
        struct cl_test t;
@
        setup_test(&t, old_obj, test, test_not, key);
        tree = nsubst(&t, new_obj, tree);
        close_test(&t);
        @(return tree)
@)

static cl_object
nsubst_cons(struct cl_test *t, cl_object new_obj, cl_object tree)
{
        cl_object l = tree;
        do {
                cl_object o = ECL_CONS_CAR(l);
                if (TEST(t, o)) {
                        ECL_RPLACA(l, new_obj);
                } else if (CONSP(o)) {
                        nsubst_cons(t, new_obj, o);
                }
                o = ECL_CONS_CDR(l);
                if (TEST(t, o)) {
                        ECL_RPLACD(l, new_obj);
                        return tree;
                }
                l = o;
        } while (CONSP(l));
        return tree;
}

static cl_object
nsubst(struct cl_test *t, cl_object new_obj, cl_object tree)
{
        if (TEST(t, tree))
                return new_obj;
        if (CONSP(tree))
                return nsubst_cons(t, new_obj, tree);
        return tree;
}

@(defun sublis (alist tree &key test test_not key)
        /* t[0] is the test for the objects in the tree, configured
           with test, test_not and key. t[1] is the test for searching
           in the association list.
         */
        struct cl_test t[2];
@
        setup_test(t, ECL_NIL, ECL_NIL, ECL_NIL, key);
        setup_test(t+1, ECL_NIL, test, test_not, ECL_NIL);
        tree = sublis(t, alist, tree);
        close_test(t+1);
        close_test(t);
        @(return tree)
@)

/*
        Sublis(alist, tree) returns
        result of substituting tree by alist.
*/
static cl_object
sublis(struct cl_test *t, cl_object alist, cl_object tree)
{
        cl_object node;
        t[1].item_compared = KEY(t, tree);
        node = do_assoc(t+1, alist);
        if (!Null(node)) {
                return ECL_CONS_CDR(node);
        }
        if (CONSP(tree)) {
                tree = CONS(sublis(t, alist, ECL_CONS_CAR(tree)),
                            sublis(t, alist, ECL_CONS_CDR(tree)));
        }
        return tree;
}

@(defun nsublis (alist tree &key test test_not key)
        /* t[0] is the test for the objects in the tree, configured
           with test, test_not and key. t[1] is the test for searching
           in the association list.
         */
        struct cl_test t[2];
@
        setup_test(t, ECL_NIL, ECL_NIL, ECL_NIL, key);
        setup_test(t+1, ECL_NIL, test, test_not, ECL_NIL);
        tree = nsublis(t, alist, tree);
        close_test(t+1);
        close_test(t);
        @(return tree)
@)

/*
        Nsublis(alist, treep) stores
        the result of substiting *treep by alist
        to *treep.
*/
static cl_object
nsublis(struct cl_test *t, cl_object alist, cl_object tree)
{
        cl_object node;
        t[1].item_compared = KEY(t, tree);
        node = do_assoc(t+1, alist);
        if (!Null(node)) {
                return ECL_CONS_CDR(node);
        }
        if (CONSP(tree)) {
                ECL_RPLACA(tree, nsublis(t, alist, ECL_CONS_CAR(tree)));
                ECL_RPLACD(tree, nsublis(t, alist, ECL_CONS_CDR(tree)));
        }
        return tree;
}

@(defun member (item list &key test test_not key)
        struct cl_test t;
@
        setup_test(&t, item, test, test_not, key);
        loop_for_in(list) {
                if (TEST(&t, ECL_CONS_CAR(list)))
                        break;
        } end_loop_for_in;
        close_test(&t);
        @(return list)
@)

bool
ecl_member_eq(cl_object x, cl_object l)
{
        loop_for_in(l) {
                if (x == ECL_CONS_CAR(l))
                        return(TRUE);
        } end_loop_for_in;
        return(FALSE);
}

cl_object
si_memq(cl_object x, cl_object l)
{
        loop_for_in(l) {
                if (x == ECL_CONS_CAR(l))
                        @(return l)
        } end_loop_for_in;
        @(return ECL_NIL)
}

/* Added for use by the compiler, instead of open coding them. Beppe */
cl_object
ecl_memql(cl_object x, cl_object l)
{
        loop_for_in(l) {
                if (ecl_eql(x, ECL_CONS_CAR(l)))
                        return(l);
        } end_loop_for_in;
        return(ECL_NIL);
}

cl_object
ecl_member(cl_object x, cl_object l)
{
        loop_for_in(l) {
                if (ecl_equal(x, ECL_CONS_CAR(l)))
                        return(l);
        } end_loop_for_in;
        return(ECL_NIL);
}
/* End of addition. Beppe */

cl_object
si_member1(cl_object item, cl_object list, cl_object test, cl_object test_not, cl_object key)
{
        struct cl_test t;

        if (key != ECL_NIL)
                item = funcall(2, key, item);
        setup_test(&t, item, test, test_not, key);
        loop_for_in(list) {
                if (TEST(&t, ECL_CONS_CAR(list)))
                        break;
        } end_loop_for_in;
        close_test(&t);
        @(return list)
}

cl_object
cl_tailp(cl_object y, cl_object x)
{
        loop_for_on(x) {
                if (ecl_eql(x, y)) @(return ECL_T);
        } end_loop_for_on(x);
        return cl_eql(x, y);
}

@(defun adjoin (item list &key test test_not key)
        cl_object output;
@
        if (narg < 2)
                FEwrong_num_arguments(@[adjoin]);
        output = @si::member1(item, list, test, test_not, key);
        if (Null(output))
                output = CONS(item, list);
        else
                output = list;
        @(return output)
@)

cl_object
cl_cons(cl_object x, cl_object y)
{
        @(return CONS(x, y))
}

cl_object
cl_acons(cl_object x, cl_object y, cl_object z)
{
        @(return CONS(CONS(x, y), z))
}

@(defun pairlis (keys data &optional a_list)
        cl_object k, d;
@
        k = keys;
        d = data;
        loop_for_in(k) {
                if (ecl_endp(d))
                        goto error;
                a_list = CONS(CONS(ECL_CONS_CAR(k), ECL_CONS_CAR(d)), a_list);
                d = CDR(d);
        } end_loop_for_in;
        if (!ecl_endp(d))
error:      FEerror("The keys ~S and the data ~S are not of the same length",
                    2, keys, data);
        @(return a_list)
@)


@(defun assoc (item a_list &key test test_not key)
        struct cl_test t;
@
        setup_test(&t, item, test, test_not, key);
        a_list = do_assoc(&t, a_list);
        close_test(&t);
        @(return a_list)
@)

static cl_object
do_assoc(struct cl_test *t, cl_object a_list)
{
        loop_for_in(a_list) {
                cl_object pair = ECL_CONS_CAR(a_list);
                if (!Null(pair)) {
                        if (!LISTP(pair))
                                FEtype_error_list(pair);
                        if (TEST(t, ECL_CONS_CAR(pair)))
                                return pair;
                }
        } end_loop_for_in;
        return ECL_NIL;
}

@(defun rassoc (item a_list &key test test_not key)
        struct cl_test t;
@
        setup_test(&t, item, test, test_not, key);
        loop_for_in(a_list) {
                cl_object pair = ECL_CONS_CAR(a_list);
                if (!Null(pair)) {
                        if (!LISTP(pair))
                                FEtype_error_list(pair);
                        if (TEST(&t, ECL_CONS_CDR(pair))) {
                                a_list = pair;
                                break;
                        }
                }
        } end_loop_for_in;
        close_test(&t);
        @(return a_list)
@)

cl_object
ecl_remove_eq(cl_object x, cl_object l)
{
        cl_object head = ECL_NIL, tail = ECL_NIL;
        loop_for_on_unsafe(l) {
                if (ECL_CONS_CAR(l) != x) {
                        cl_object cons = ecl_list1(ECL_CONS_CAR(l));
                        if (Null(tail)) {
                                head = tail = cons;
                        } else {
                                ECL_RPLACD(tail, cons);
                                tail = cons;
                        }
                }
        } end_loop_for_on_unsafe(l);
        return head;
}

cl_object
ecl_delete_eq(cl_object x, cl_object l)
{
        cl_object head = l;
        cl_object *p = &head;
        while (!ECL_ATOM(l)) {
                if (ECL_CONS_CAR(l) == x) {
                        *p = l = ECL_CONS_CDR(l);
                } else {
                        p = &ECL_CONS_CDR(l);
                        l = *p;
                }
        }
        return head;
}

/* Added for use by the compiler, instead of open coding them. Beppe */
cl_object
ecl_assq(cl_object x, cl_object l)
{
        loop_for_in(l) {
                cl_object pair = ECL_CONS_CAR(l);
                if (x == CAR(pair))
                        return pair;
        } end_loop_for_in;
        return(ECL_NIL);
}

cl_object
ecl_assql(cl_object x, cl_object l)
{
        loop_for_in(l) {
                cl_object pair = ECL_CONS_CAR(l);
                if (ecl_eql(x, CAR(pair)))
                        return pair;
        } end_loop_for_in;
        return(ECL_NIL);
}

cl_object
ecl_assoc(cl_object x, cl_object l)
{
        loop_for_in(l) {
                cl_object pair = ECL_CONS_CAR(l);
                if (ecl_equal(x, CAR(pair)))
                        return pair;
        } end_loop_for_in;
        return(ECL_NIL);
}

cl_object
ecl_assqlp(cl_object x, cl_object l)
{
        loop_for_in(l) {
                cl_object pair = ECL_CONS_CAR(l);
                if (ecl_equalp(x, CAR(pair)))
                        return pair;
        } end_loop_for_in;
        return(ECL_NIL);
}
/* End of addition. Beppe */
