/*
  Racket
  Copyright (c) 2004-2012 PLT Scheme Inc.
  Copyright (c) 1995-2001 Matthew Flatt

    This library 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.

    This library 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301 USA.

  libscheme
  Copyright (c) 1994 Brent Benson
  All rights reserved.
*/

#include "schpriv.h"
#include "schmach.h"

/* globals */
READ_ONLY Scheme_Object *scheme_vector_proc;
READ_ONLY Scheme_Object *scheme_vector_immutable_proc;
READ_ONLY Scheme_Object *scheme_vector_ref_proc;
READ_ONLY Scheme_Object *scheme_vector_set_proc;

/* locals */
static Scheme_Object *vector_p (int argc, Scheme_Object *argv[]);
static Scheme_Object *make_vector (int argc, Scheme_Object *argv[]);
static Scheme_Object *vector (int argc, Scheme_Object *argv[]);
static Scheme_Object *vector_immutable (int argc, Scheme_Object *argv[]);
static Scheme_Object *vector_length (int argc, Scheme_Object *argv[]);
static Scheme_Object *vector_to_list (int argc, Scheme_Object *argv[]);
static Scheme_Object *list_to_vector (int argc, Scheme_Object *argv[]);
static Scheme_Object *vector_fill (int argc, Scheme_Object *argv[]);
static Scheme_Object *vector_copy_bang(int argc, Scheme_Object *argv[]);
static Scheme_Object *vector_to_immutable (int argc, Scheme_Object *argv[]);
static Scheme_Object *vector_to_values (int argc, Scheme_Object *argv[]);
static Scheme_Object *chaperone_vector(int argc, Scheme_Object **argv);
static Scheme_Object *impersonate_vector(int argc, Scheme_Object **argv);

static Scheme_Object *unsafe_vector_len (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_vector_ref (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_vector_set (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_vector_star_len (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_vector_star_ref (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_vector_star_set (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_struct_ref (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_struct_set (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_struct_star_ref (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_struct_star_set (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_string_len (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_string_ref (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_string_set (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_bytes_len (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_bytes_ref (int argc, Scheme_Object *argv[]);
static Scheme_Object *unsafe_bytes_set (int argc, Scheme_Object *argv[]);

void
scheme_init_vector (Scheme_Env *env)
{
  Scheme_Object *p;

  p = scheme_make_folding_prim(vector_p, "vector?", 1, 1, 1);
  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_UNARY_INLINED;
  scheme_add_global_constant("vector?", p, env);

  scheme_add_global_constant("make-vector", 
			     scheme_make_immed_prim(make_vector, 
						    "make-vector", 
						    1, 2), 
			     env);
  
  REGISTER_SO(scheme_vector_proc);
  p = scheme_make_immed_prim(vector, "vector", 0, -1);
  scheme_vector_proc = p;
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_UNARY_INLINED
                                | SCHEME_PRIM_IS_BINARY_INLINED
                                | SCHEME_PRIM_IS_NARY_INLINED);
  scheme_add_global_constant("vector", p, env);

  REGISTER_SO(scheme_vector_immutable_proc);
  p = scheme_make_immed_prim(vector_immutable, "vector-immutable", 0, -1);
  scheme_vector_immutable_proc = p;
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_UNARY_INLINED
                                | SCHEME_PRIM_IS_BINARY_INLINED
                                | SCHEME_PRIM_IS_NARY_INLINED);
  scheme_add_global_constant("vector-immutable", p, env);
  
  p = scheme_make_folding_prim(vector_length, "vector-length", 1, 1, 1);
  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_UNARY_INLINED;
  scheme_add_global_constant("vector-length", p, env);

  REGISTER_SO(scheme_vector_ref_proc);
  p = scheme_make_noncm_prim(scheme_checked_vector_ref, 
                             "vector-ref", 
                             2, 2);
  scheme_vector_ref_proc = p;
  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_BINARY_INLINED;
  scheme_add_global_constant("vector-ref", p, env);

  REGISTER_SO(scheme_vector_set_proc);
  p = scheme_make_noncm_prim(scheme_checked_vector_set,
                             "vector-set!", 
                             3, 3);
  scheme_vector_set_proc = p;
  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_NARY_INLINED;
  scheme_add_global_constant("vector-set!", p, env);

  scheme_add_global_constant("vector->list", 
			     scheme_make_immed_prim(vector_to_list, 
						    "vector->list", 
						    1, 1), 
			     env);
  scheme_add_global_constant("list->vector", 
			     scheme_make_immed_prim(list_to_vector, 
						    "list->vector", 
						    1, 1), 
			     env);
  scheme_add_global_constant("vector-fill!", 
			     scheme_make_immed_prim(vector_fill, 
						    "vector-fill!", 
						    2, 2), 
			     env);
  scheme_add_global_constant("vector-copy!", 
			     scheme_make_immed_prim(vector_copy_bang, 
						    "vector-copy!", 
						    3, 5), 
			     env);
  scheme_add_global_constant("vector->immutable-vector", 
			     scheme_make_immed_prim(vector_to_immutable, 
						    "vector->immutable-vector", 
						    1, 1), 
			     env);
  scheme_add_global_constant("vector->values", 
			     scheme_make_prim_w_arity2(vector_to_values, 
                                                       "vector->values", 
                                                       1, 3,
                                                       0, -1), 
			     env);

  scheme_add_global_constant("chaperone-vector",
                             scheme_make_prim_w_arity(chaperone_vector,
                                                      "chaperone-vector",
                                                      3, -1),
                             env);
  scheme_add_global_constant("impersonate-vector",
                             scheme_make_prim_w_arity(impersonate_vector,
                                                      "impersonate-vector",
                                                      3, -1),
                             env);
}

void
scheme_init_unsafe_vector (Scheme_Env *env)
{
  Scheme_Object *p;

  p = scheme_make_immed_prim(unsafe_vector_len, "unsafe-vector-length", 1, 1);
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_UNARY_INLINED
                                | SCHEME_PRIM_IS_UNSAFE_FUNCTIONAL);
  scheme_add_global_constant("unsafe-vector-length", p, env);

  p = scheme_make_immed_prim(unsafe_vector_star_len, "unsafe-vector*-length", 1, 1);
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_UNARY_INLINED
                                | SCHEME_PRIM_IS_UNSAFE_FUNCTIONAL);
  scheme_add_global_constant("unsafe-vector*-length", p, env);

  p = scheme_make_immed_prim(unsafe_vector_ref, "unsafe-vector-ref", 2, 2);
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_BINARY_INLINED
                                | SCHEME_PRIM_IS_UNSAFE_OMITABLE);
  scheme_add_global_constant("unsafe-vector-ref", p, env);

  p = scheme_make_immed_prim(unsafe_vector_star_ref, "unsafe-vector*-ref", 2, 2);
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_BINARY_INLINED
                                | SCHEME_PRIM_IS_UNSAFE_OMITABLE);
  scheme_add_global_constant("unsafe-vector*-ref", p, env);

  p = scheme_make_immed_prim(unsafe_vector_set, "unsafe-vector-set!", 3, 3);
  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_NARY_INLINED;
  scheme_add_global_constant("unsafe-vector-set!", p, env);  

  p = scheme_make_immed_prim(unsafe_vector_star_set, "unsafe-vector*-set!", 3, 3);
  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_NARY_INLINED;
  scheme_add_global_constant("unsafe-vector*-set!", p, env);  

  p = scheme_make_immed_prim(unsafe_struct_ref, "unsafe-struct-ref", 2, 2);
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_BINARY_INLINED
                                | SCHEME_PRIM_IS_UNSAFE_OMITABLE);
  scheme_add_global_constant("unsafe-struct-ref", p, env);

  p = scheme_make_immed_prim(unsafe_struct_star_ref, "unsafe-struct*-ref", 2, 2);
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_BINARY_INLINED
                                | SCHEME_PRIM_IS_UNSAFE_OMITABLE);
  scheme_add_global_constant("unsafe-struct*-ref", p, env);

  p = scheme_make_immed_prim(unsafe_struct_set, "unsafe-struct-set!", 3, 3);
  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_NARY_INLINED;
  scheme_add_global_constant("unsafe-struct-set!", p, env);  

  p = scheme_make_immed_prim(unsafe_struct_star_set, "unsafe-struct*-set!", 3, 3);
  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_NARY_INLINED;
  scheme_add_global_constant("unsafe-struct*-set!", p, env);  

  p = scheme_make_immed_prim(unsafe_string_len, "unsafe-string-length", 1, 1);
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_UNARY_INLINED
                                | SCHEME_PRIM_IS_UNSAFE_FUNCTIONAL);
  scheme_add_global_constant("unsafe-string-length", p, env);

  p = scheme_make_immed_prim(unsafe_string_ref, "unsafe-string-ref", 2, 2);
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_BINARY_INLINED
                                | SCHEME_PRIM_IS_UNSAFE_OMITABLE);
  scheme_add_global_constant("unsafe-string-ref", p, env);

  p = scheme_make_immed_prim(unsafe_string_set, "unsafe-string-set!", 3, 3);
  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_NARY_INLINED;
  scheme_add_global_constant("unsafe-string-set!", p, env);

  p = scheme_make_immed_prim(unsafe_bytes_len, "unsafe-bytes-length", 1, 1);
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_UNARY_INLINED
                                | SCHEME_PRIM_IS_UNSAFE_FUNCTIONAL);
  scheme_add_global_constant("unsafe-bytes-length", p, env);

  p = scheme_make_immed_prim(unsafe_bytes_ref, "unsafe-bytes-ref", 2, 2);
  SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_BINARY_INLINED
                                | SCHEME_PRIM_IS_UNSAFE_OMITABLE);
  scheme_add_global_constant("unsafe-bytes-ref", p, env);

  p = scheme_make_immed_prim(unsafe_bytes_set, "unsafe-bytes-set!", 3, 3);
  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_NARY_INLINED;
  scheme_add_global_constant("unsafe-bytes-set!", p, env);
}

#define VECTOR_BYTES(size) (sizeof(Scheme_Vector) + ((size) - mzFLEX_DELTA) * sizeof(Scheme_Object *))
#define REV_VECTOR_BYTES(size) (((size) - (sizeof(Scheme_Vector) - (mzFLEX_DELTA * sizeof(Scheme_Object *)))) / sizeof(Scheme_Object *))

Scheme_Object *
scheme_make_vector (intptr_t size, Scheme_Object *fill)
{
  Scheme_Object *vec;
  intptr_t i;

  if (size < 0) {
    vec = scheme_make_integer(size);
    scheme_wrong_type("make-vector", "non-negative exact integer", -1, 0, &vec);
  }

  if (size < 1024) {
    vec = (Scheme_Object *)scheme_malloc_tagged(VECTOR_BYTES(size));
  } else {
    size_t sz;
    sz = VECTOR_BYTES(size);
    if (REV_VECTOR_BYTES(sz) != size)
      /* overflow */
      scheme_raise_out_of_memory(NULL, NULL);
    else
      vec = (Scheme_Object *)scheme_malloc_fail_ok(scheme_malloc_tagged, sz);
  }

  vec->type = scheme_vector_type;
  SCHEME_VEC_SIZE(vec) = size;

  if (fill) {
    for (i = 0; i < size; i++) {
      SCHEME_VEC_ELS(vec)[i] = fill;
    }
  }

  return vec;
}

/* locals */

static Scheme_Object *
vector_p (int argc, Scheme_Object *argv[])
{
  return (SCHEME_CHAPERONE_VECTORP(argv[0]) ? scheme_true : scheme_false);
}

static Scheme_Object *
make_vector (int argc, Scheme_Object *argv[])
{
  Scheme_Object *vec, *fill;
  intptr_t len;

  len = scheme_extract_index("make-vector", 0, argc, argv, -1, 0);

  if ((len == -1) 
      /* also watch for overflow: */
      || (REV_VECTOR_BYTES(VECTOR_BYTES(len)) != len)) {
    scheme_raise_out_of_memory("make-vector", "making vector of length %s",
			       scheme_make_provided_string(argv[0], 1, NULL));
  }

  if (argc == 2)
    fill = argv[1];
  else
    fill = scheme_make_integer(0);

  vec = scheme_make_vector(len, fill);

  return vec;
}

static Scheme_Object *
vector (int argc, Scheme_Object *argv[])
{
  Scheme_Object *vec;
  int i;

  vec = scheme_make_vector (argc, 0);
  for (i = 0; i < argc ; i++) {
    SCHEME_VEC_ELS(vec)[i] = argv[i];
  }

  return vec;
}

static Scheme_Object *
vector_immutable (int argc, Scheme_Object *argv[])
{
  Scheme_Object *vec;

  vec = vector(argc, argv);
  SCHEME_SET_IMMUTABLE(vec);

  return vec;
}

static Scheme_Object *
vector_length (int argc, Scheme_Object *argv[])
{
  Scheme_Object *vec = argv[0];

  if (SCHEME_NP_CHAPERONEP(vec))
    vec = SCHEME_CHAPERONE_VAL(vec);

  if (!SCHEME_VECTORP(vec))
    scheme_wrong_type("vector-length", "vector", 0, argc, argv);

  return scheme_make_integer(SCHEME_VEC_SIZE(vec));
}

Scheme_Object *scheme_vector_length(Scheme_Object *v)
{
  Scheme_Object *a[1];
  a[0] = v;
  return vector_length(1, a);
}

void scheme_bad_vec_index(char *name, Scheme_Object *i, const char *what, Scheme_Object *vec, 
                          intptr_t bottom, intptr_t len)
{
  if (len) {
    intptr_t n = len - 1;
    char *vstr;
    intptr_t vlen;
    vstr = scheme_make_provided_string(vec, 2, &vlen);
    scheme_raise_exn(MZEXN_FAIL_CONTRACT,
		     "%s: index %s out of range [%ld, %ld] for %s: %t",
		     name, 
		     scheme_make_provided_string(i, 2, NULL), 
		     bottom, n,
                     what,
		     vstr, vlen);
  } else
    scheme_raise_exn(MZEXN_FAIL_CONTRACT,
		     "%s: bad index %s for empty %s",
		     name,
		     scheme_make_provided_string(i, 0, NULL),
                     what);
}

static Scheme_Object *
bad_index(char *name, Scheme_Object *i, Scheme_Object *vec, int bottom)
{
  scheme_bad_vec_index(name, i, "vector", vec, bottom, 
                       (SCHEME_NP_CHAPERONEP(vec)
                        ? SCHEME_VEC_SIZE(SCHEME_CHAPERONE_VAL(vec))
                        : SCHEME_VEC_SIZE(vec)));
  return NULL;
}

static Scheme_Object *chaperone_vector_ref_k(void)
{
  Scheme_Thread *p = scheme_current_thread;
  Scheme_Object *o = (Scheme_Object *)p->ku.k.p1;

  p->ku.k.p1 = NULL;

  return scheme_chaperone_vector_ref(o, p->ku.k.i1);
}

static Scheme_Object *chaperone_vector_ref_overflow(Scheme_Object *o, int i)
{
  Scheme_Thread *p = scheme_current_thread;

  p->ku.k.p1 = (void *)o;
  p->ku.k.i1 = i;

  return scheme_handle_stack_overflow(chaperone_vector_ref_k);
}

Scheme_Object *scheme_chaperone_vector_ref(Scheme_Object *o, int i)
{
  if (!SCHEME_NP_CHAPERONEP(o)) {
    return SCHEME_VEC_ELS(o)[i];
  } else {
    Scheme_Chaperone *px = (Scheme_Chaperone *)o;
    Scheme_Object *a[3], *red, *orig;

#ifdef DO_STACK_CHECK
    {
# include "mzstkchk.h"
      return chaperone_vector_ref_overflow(o, i);
    }
#endif

    orig = scheme_chaperone_vector_ref(px->prev, i);

    if (SCHEME_VECTORP(px->redirects)) {
      /* chaperone was on property accessors */
      return orig;
    }

    a[0] = px->prev;
    a[1] = scheme_make_integer(i);
    a[2] = orig;
    red = SCHEME_CAR(px->redirects);
    o = _scheme_apply(red, 3, a);

    if (!(SCHEME_CHAPERONE_FLAGS(px) & SCHEME_CHAPERONE_IS_IMPERSONATOR))
      if (!scheme_chaperone_of(o, orig))
        scheme_raise_exn(MZEXN_FAIL_CONTRACT,
                         "vector-ref: chaperone produced a result: %V that is not a chaperone of the original result: %V",
                         o, 
                         orig);

    return o;
  }
}

Scheme_Object *
scheme_checked_vector_ref (int argc, Scheme_Object *argv[])
{
  intptr_t i, len;
  Scheme_Object *vec;

  vec = argv[0];
  if (SCHEME_CHAPERONEP(vec))
    vec = SCHEME_CHAPERONE_VAL(vec);

  if (!SCHEME_VECTORP(vec))
    scheme_wrong_type("vector-ref", "vector", 0, argc, argv);

  len = SCHEME_VEC_SIZE(vec);

  i = scheme_extract_index("vector-ref", 1, argc, argv, len, 0);

  if (i >= len)
    return bad_index("vector-ref", argv[1], argv[0], 0);

  if (!SAME_OBJ(vec, argv[0]))
    /* chaperone */
    return scheme_chaperone_vector_ref(argv[0], i);
  else
    return (SCHEME_VEC_ELS(vec))[i];
}

void scheme_chaperone_vector_set(Scheme_Object *o, int i, Scheme_Object *v)
{
  while (1) {
    if (!SCHEME_NP_CHAPERONEP(o)) {
      SCHEME_VEC_ELS(o)[i] = v;
      return;
    } else {
      Scheme_Chaperone *px = (Scheme_Chaperone *)o;
      Scheme_Object *a[3], *red;
      
      o = px->prev;
      a[0] = o;
      a[1] = scheme_make_integer(i);
      a[2] = v;
      red = SCHEME_CDR(px->redirects);
      v = _scheme_apply(red, 3, a);

      if (!(SCHEME_CHAPERONE_FLAGS(px) & SCHEME_CHAPERONE_IS_IMPERSONATOR))
        if (!scheme_chaperone_of(v, a[2]))
          scheme_raise_exn(MZEXN_FAIL_CONTRACT,
                           "vector-set!: chaperone produced a result: %V that is not a chaperone of the original result: %V",
                           v, 
                           a[2]);
    }
  }
}

Scheme_Object *
scheme_checked_vector_set(int argc, Scheme_Object *argv[])
{
  Scheme_Object *vec = argv[0];
  intptr_t i, len;

  if (SCHEME_CHAPERONEP(vec))
    vec = SCHEME_CHAPERONE_VAL(vec);

  if (!SCHEME_MUTABLE_VECTORP(vec))
    scheme_wrong_type("vector-set!", "mutable vector", 0, argc, argv);

  len = SCHEME_VEC_SIZE(vec);

  i = scheme_extract_index("vector-set!", 1, argc, argv, len, 0);

  if (i >= len)
    return bad_index("vector-set!", argv[1], argv[0], 0);

  if (!SAME_OBJ(vec, argv[0]))
    scheme_chaperone_vector_set(argv[0], i, argv[2]);
  else
    SCHEME_VEC_ELS(vec)[i] = argv[2];

  return scheme_void;
}

# define cons(car, cdr) scheme_make_pair(car, cdr)

Scheme_Object *
scheme_vector_to_list (Scheme_Object *vec)
{
  int i;
  Scheme_Object *pair = scheme_null;

  i = SCHEME_VEC_SIZE(vec);

  if (i < 0xFFF) {
    for (; i--; ) {
      pair = cons(SCHEME_VEC_ELS(vec)[i], pair);
    }
  } else {
    for (; i--; ) {
      if (!(i & 0xFFF))
	SCHEME_USE_FUEL(0xFFF);
      pair = cons(SCHEME_VEC_ELS(vec)[i], pair);
    }
  }

  return pair;
}


Scheme_Object *
chaperone_vector_to_list (Scheme_Object *vec)
{
  int i;
  Scheme_Object *pair = scheme_null;

  i = SCHEME_VEC_SIZE(SCHEME_CHAPERONE_VAL(vec));

  for (; i--; ) {
    if (!(i & 0xFFF))
      SCHEME_USE_FUEL(0xFFF);
    pair = cons(scheme_chaperone_vector_ref(vec, i), pair);
  }

  return pair;
}

static Scheme_Object *
vector_to_list (int argc, Scheme_Object *argv[])
{
  Scheme_Object *vec = argv[0];

  if (SCHEME_NP_CHAPERONEP(vec))
    vec = SCHEME_CHAPERONE_VAL(vec);

  if (!SCHEME_VECTORP(vec)) {
    scheme_wrong_type("vector->list", "vector", 0, argc, argv);
    return NULL;
  }

  if (!SAME_OBJ(vec, argv[0]))
    return chaperone_vector_to_list(argv[0]);
  else
    return scheme_vector_to_list(vec);
}

static Scheme_Object *
list_to_vector (int argc, Scheme_Object *argv[])
{
  return scheme_list_to_vector(argv[0]);
}

Scheme_Object *
scheme_list_to_vector (Scheme_Object *list)
{
  intptr_t len, i;
  Scheme_Object *vec, *orig = list;

  len = scheme_proper_list_length(list);
  if (len < 0)
    scheme_wrong_type("list->vector", "proper list", -1, 0, &orig);

  vec = scheme_make_vector(len, NULL);
  for (i = 0; i < len; i++) {
    SCHEME_VEC_ELS(vec)[i] = SCHEME_CAR(list);
    list = SCHEME_CDR(list);
  }

  return vec;
}

static Scheme_Object *
vector_fill (int argc, Scheme_Object *argv[])
{
  int i, sz;
  Scheme_Object *v, *vec = argv[0];

  if (SCHEME_NP_CHAPERONEP(vec))
    vec = SCHEME_CHAPERONE_VAL(vec);
  
  if (!SCHEME_MUTABLE_VECTORP(vec))
    scheme_wrong_type("vector-fill!", "mutable vector", 0, argc, argv);

  v = argv[1];
  sz = SCHEME_VEC_SIZE(vec);
  if (SAME_OBJ(vec, argv[0])) {
    for (i = 0; i < sz; i++) {
      SCHEME_VEC_ELS(argv[0])[i] = v;
    }
  } else {
    for (i = 0; i < sz; i++) {
      scheme_chaperone_vector_set(argv[0], i, v);
    }
  }

  return scheme_void;
}

static Scheme_Object *vector_copy_bang(int argc, Scheme_Object *argv[])
{
  Scheme_Object *s1, *s2;
  intptr_t istart, ifinish;
  intptr_t ostart, ofinish;
  int slow = 0;

  s1 = argv[0];
  if (SCHEME_NP_CHAPERONEP(s1)) {
    slow = 1;
    s1 = SCHEME_CHAPERONE_VAL(s1);
  }
  if (!SCHEME_MUTABLE_VECTORP(s1))
    scheme_wrong_type("vector-copy!", "mutable vector", 0, argc, argv);

  scheme_do_get_substring_indices("vector-copy!", s1, 
                                  argc, argv, 1, 5, 
                                  &ostart, &ofinish, SCHEME_VEC_SIZE(s1));

  s2 = argv[2];
  if (SCHEME_NP_CHAPERONEP(s2)) {
    slow = 1;
    s2 = SCHEME_CHAPERONE_VAL(s2);
  }
  if (!SCHEME_VECTORP(s2))
    scheme_wrong_type("vector-copy!", "vector", 2, argc, argv);

  scheme_do_get_substring_indices("vector-copy!", s2, 
                                  argc, argv, 3, 4, 
                                  &istart, &ifinish, SCHEME_VEC_SIZE(s2));

  if ((ofinish - ostart) < (ifinish - istart)) {
    scheme_arg_mismatch("vector-copy!",
			"not enough room in target vector: ",
			argv[2]);
    return NULL;
  }

  if (slow) {
    int i, o;
    for (i = istart, o = ostart; i < ifinish; i++, o++) {
      scheme_chaperone_vector_set(argv[0], o, scheme_chaperone_vector_ref(argv[2], i));
    }
  } else {
    memmove(SCHEME_VEC_ELS(s1) + ostart,
            SCHEME_VEC_ELS(s2) + istart,
            (ifinish - istart) * sizeof(Scheme_Object*));
  }
  
  return scheme_void;
}

Scheme_Object *scheme_chaperone_vector_copy(Scheme_Object *vec)
{
  int len;
  Scheme_Object *a[3], *vec2;

  if (SCHEME_NP_CHAPERONEP(vec))
    len = SCHEME_VEC_SIZE(SCHEME_CHAPERONE_VAL(vec));
  else
    len = SCHEME_VEC_SIZE(vec);

  vec2 = scheme_make_vector(len, NULL);
  a[0] = vec2;
  a[1] = scheme_make_integer(0);
  a[2] = vec;

  (void)vector_copy_bang(3, a);

  return vec2;
}

static Scheme_Object *vector_to_immutable (int argc, Scheme_Object *argv[])
{
  Scheme_Object *vec, *ovec, *v;
  intptr_t len, i;

  vec = argv[0];
  if (SCHEME_NP_CHAPERONEP(vec))
    vec = SCHEME_CHAPERONE_VAL(vec);  

  if (!SCHEME_VECTORP(vec))
    scheme_wrong_type("vector->immutable-vector", "vector", 0, argc, argv);

  if (SCHEME_IMMUTABLEP(vec))
    return argv[0];

  ovec = vec;
  len = SCHEME_VEC_SIZE(ovec);

  vec = scheme_make_vector(len, NULL);
  if (!SAME_OBJ(ovec, argv[0])) {
    for (i = 0; i < len; i++) {
      v = scheme_chaperone_vector_ref(argv[0], i);
      SCHEME_VEC_ELS(vec)[i] = v;
    }
  } else {
    for (i = 0; i < len; i++) {
      SCHEME_VEC_ELS(vec)[i] = SCHEME_VEC_ELS(ovec)[i];
    }
  }
  SCHEME_SET_IMMUTABLE(vec);

  return vec;  
}

static Scheme_Object *vector_to_values (int argc, Scheme_Object *argv[])
{
  Scheme_Thread *p;
  Scheme_Object *vec, **a;
  intptr_t len, start, finish, i;

  vec = argv[0];
  if (SCHEME_NP_CHAPERONEP(vec))
    vec = SCHEME_CHAPERONE_VAL(vec);  

  if (!SCHEME_VECTORP(vec))
    scheme_wrong_type("vector->values", "vector", 0, argc, argv);

  len = SCHEME_VEC_SIZE(vec);

  if (argc > 1)
    start = scheme_extract_index("vector->values", 1, argc, argv, len + 1, 0);
  else
    start = 0;
  if (argc > 2)
    finish = scheme_extract_index("vector->values", 2, argc, argv, len + 1, 0);
  else
    finish = len;

  if (!(start <= len)) {
    bad_index("vector->values", argv[1], argv[0], 0);
  }
  if (!(finish >= start && finish <= len)) {
    bad_index("vector->values", argv[2], argv[0], start);
  }

  len = finish - start;
  if (len == 1) {
    if (!SAME_OBJ(vec, argv[0]))
      return scheme_chaperone_vector_ref(argv[0], start);
    else
      return SCHEME_VEC_ELS(vec)[start];
  }

  p = scheme_current_thread;
  if (p->values_buffer && (p->values_buffer_size >= len))
    a = p->values_buffer;
  else {
    a = MALLOC_N(Scheme_Object *, len);
    p->values_buffer = a;
    p->values_buffer_size = len;
  }

  p->ku.multiple.array = a;
  p->ku.multiple.count = len;

  if (!SAME_OBJ(vec, argv[0])) {
    for (i = 0; i < len; i++) {
      vec = scheme_chaperone_vector_ref(argv[0], start + i);
      a[i] = vec;
    }
  } else {
    for (i = 0; i < len; i++) {
      a[i] = SCHEME_VEC_ELS(vec)[start + i];
    }
  }

  return SCHEME_MULTIPLE_VALUES;
}

static Scheme_Object *do_chaperone_vector(const char *name, int is_impersonator, int argc, Scheme_Object **argv)
{
  Scheme_Chaperone *px;
  Scheme_Object *val = argv[0];
  Scheme_Object *redirects;
  Scheme_Hash_Tree *props;

  if (SCHEME_CHAPERONEP(val))
    val = SCHEME_CHAPERONE_VAL(val);

  if (!SCHEME_VECTORP(val)
      || (is_impersonator && !SCHEME_MUTABLEP(val)))
    scheme_wrong_type(name, is_impersonator ? "mutable vector" : "vector", 0, argc, argv);
  scheme_check_proc_arity(name, 3, 1, argc, argv);
  scheme_check_proc_arity(name, 3, 2, argc, argv);

  props = scheme_parse_chaperone_props(name, 3, argc, argv);

  redirects = scheme_make_pair(argv[1], argv[2]);
  
  px = MALLOC_ONE_TAGGED(Scheme_Chaperone);
  px->iso.so.type = scheme_chaperone_type;
  px->props = props;
  px->val = val;
  px->prev = argv[0];
  px->redirects = redirects;

  if (is_impersonator)
    SCHEME_CHAPERONE_FLAGS(px) |= SCHEME_CHAPERONE_IS_IMPERSONATOR;

  return (Scheme_Object *)px;
}

static Scheme_Object *chaperone_vector(int argc, Scheme_Object **argv)
{
  return do_chaperone_vector("chaperone-vector", 0, argc, argv);
}

static Scheme_Object *impersonate_vector(int argc, Scheme_Object **argv)
{
  return do_chaperone_vector("impersonate-vector", 1, argc, argv);
}

/************************************************************/
/*                        unsafe                            */
/************************************************************/

static Scheme_Object *unsafe_vector_len (int argc, Scheme_Object *argv[])
{
  Scheme_Object *vec = argv[0];
  intptr_t n;
  if (SCHEME_NP_CHAPERONEP(vec)) vec = SCHEME_CHAPERONE_VAL(vec);
  n = SCHEME_VEC_SIZE(vec);
  return scheme_make_integer(n);
}

static Scheme_Object *unsafe_vector_ref (int argc, Scheme_Object *argv[])
{
  if (SCHEME_NP_CHAPERONEP(argv[0]))
    return scheme_chaperone_vector_ref(argv[0], SCHEME_INT_VAL(argv[1]));
  else
    return SCHEME_VEC_ELS(argv[0])[SCHEME_INT_VAL(argv[1])];
}

static Scheme_Object *unsafe_vector_set (int argc, Scheme_Object *argv[])
{
  if (SCHEME_NP_CHAPERONEP(argv[0]))
    scheme_chaperone_vector_set(argv[0], SCHEME_INT_VAL(argv[1]), argv[2]);
  else
    SCHEME_VEC_ELS(argv[0])[SCHEME_INT_VAL(argv[1])] = argv[2];
  return scheme_void;
}

static Scheme_Object *unsafe_vector_star_len (int argc, Scheme_Object *argv[])
{
  Scheme_Object *vec = argv[0];
  intptr_t n;
  n = SCHEME_VEC_SIZE(vec);
  return scheme_make_integer(n);
}

static Scheme_Object *unsafe_vector_star_ref (int argc, Scheme_Object *argv[])
{
  return SCHEME_VEC_ELS(argv[0])[SCHEME_INT_VAL(argv[1])];
}

static Scheme_Object *unsafe_vector_star_set (int argc, Scheme_Object *argv[])
{
  SCHEME_VEC_ELS(argv[0])[SCHEME_INT_VAL(argv[1])] = argv[2];
  return scheme_void;
}

static Scheme_Object *unsafe_struct_ref (int argc, Scheme_Object *argv[])
{
  if (SCHEME_CHAPERONEP(argv[0]))
    return scheme_struct_ref(argv[0], SCHEME_INT_VAL(argv[1]));
  else
    return ((Scheme_Structure *)argv[0])->slots[SCHEME_INT_VAL(argv[1])];
}

static Scheme_Object *unsafe_struct_set (int argc, Scheme_Object *argv[])
{
  if (SCHEME_CHAPERONEP(argv[0]))
    scheme_struct_set(argv[0], SCHEME_INT_VAL(argv[1]), argv[2]);
  else
    ((Scheme_Structure *)argv[0])->slots[SCHEME_INT_VAL(argv[1])] = argv[2];
  return scheme_void;
}

static Scheme_Object *unsafe_struct_star_ref (int argc, Scheme_Object *argv[])
{
  return ((Scheme_Structure *)argv[0])->slots[SCHEME_INT_VAL(argv[1])];
}

static Scheme_Object *unsafe_struct_star_set (int argc, Scheme_Object *argv[])
{
  ((Scheme_Structure *)argv[0])->slots[SCHEME_INT_VAL(argv[1])] = argv[2];
  return scheme_void;
}

static Scheme_Object *unsafe_string_len (int argc, Scheme_Object *argv[])
{
  intptr_t n = SCHEME_CHAR_STRLEN_VAL(argv[0]);
  return scheme_make_integer(n);
}

static Scheme_Object *unsafe_string_ref (int argc, Scheme_Object *argv[])
{
  mzchar v;
  v = SCHEME_CHAR_STR_VAL(argv[0])[SCHEME_INT_VAL(argv[1])];
  return scheme_make_ascii_character(v);
}

static Scheme_Object *unsafe_string_set (int argc, Scheme_Object *argv[])
{
  SCHEME_CHAR_STR_VAL(argv[0])[SCHEME_INT_VAL(argv[1])] = SCHEME_CHAR_VAL(argv[2]);
  return scheme_void;
}

static Scheme_Object *unsafe_bytes_len (int argc, Scheme_Object *argv[])
{
  intptr_t n = SCHEME_BYTE_STRLEN_VAL(argv[0]);
  return scheme_make_integer(n);
}

static Scheme_Object *unsafe_bytes_ref (int argc, Scheme_Object *argv[])
{
  intptr_t v;
  v = (unsigned char)SCHEME_BYTE_STR_VAL(argv[0])[SCHEME_INT_VAL(argv[1])];
  return scheme_make_integer(v);
}

static Scheme_Object *unsafe_bytes_set (int argc, Scheme_Object *argv[])
{
  SCHEME_BYTE_STR_VAL(argv[0])[SCHEME_INT_VAL(argv[1])] = (char)SCHEME_INT_VAL(argv[2]);
  return scheme_void;
}
