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/* -*- c -*- 
|| This file is part of Pike. For copyright information see COPYRIGHT. 
|| Pike is distributed under GPL, LGPL and MPL. See the file COPYING 
|| for more information. 
*/ 
 
#include "global.h" 
 
#include "object.h" 
#include "svalue.h" 
#include "array.h" 
#include "pike_error.h" 
#include "interpret.h" 
#include "stralloc.h" 
#include "program.h" 
#include "operators.h" 
#include "pike_types.h" 
 
#include "program_id.h" 
 
#include "module_support.h" 
#include "sequence.h" 
 
 
/*! @module ADT 
 */ 
 
 
DECLARATIONS 
 
/*! @class Sequence 
 *! The sequence work similar to an array but has the possibilities to 
 *! insert and remove elements. It also has a more powerful iterator. 
 */ 
 
PIKECLASS Sequence 
{ 
 
  CVAR int pos; 
  CVAR struct array *a; 
 
 
  //if there is more than one reference to this array copy it. 
 
  static inline void should_copy(void) 
  { 
    if (THIS->a->refs > 1) 
    { 
      struct array *b = copy_array(THIS->a); 
      free_array(THIS->a); 
      THIS->a = b; 
    } 
  } 
 
 
/*! @decl mixed `[](int index) 
 *! Index operator. 
 *! 
 *! @param index 
 *!   The index to get the value for, could be negative to index from the end. 
 *! 
 *! @returns 
 *!   The value at the index @[index]. 
 *! 
 *! @throws 
 *!   An error if the index is out of range. 
 */ 
 
  PIKEFUN mixed `[](mixed index) { 
 
    simple_array_index_no_free(Pike_sp, THIS->a, index); 
    Pike_sp++; 
  } 
 
 
/*! @decl mixed `[]=(int index, mixed value) 
 *! Index assign operator. 
 *! Set the value at the index @[index] to be @[value]. 
 *! 
 *! @param index 
 *!   The index to set. 
 *! 
 *! @param value 
 *!   The new value. 
 *! 
 *! @returns 
 *!   The new value at the index @[index]. 
 *! 
 */ 
 
  PIKEFUN mixed `[]=(mixed index, mixed value) { 
    should_copy(); 
    simple_set_index(THIS->a, index, value); 
  } 
 
 
/*! @decl Sequence `+(Sequence ... coll) 
 *! Addition operator 
 *! 
 *! Append the content of @@@[coll] to this sequence and return the results 
 *! as a new @[Sequence]. 
 *! 
 *! @param coll 
 *!   The sequences to append to this sequence. 
 *! 
 *! @returns 
 *!   The result of the append as a new @[Sequence]. 
 */ 
 
  PIKEFUN object `+(object ... coll) 
  { 
    int i; 
 
    ref_push_array(THIS->a); 
 
    for(i=0; i < args; i++) { 
      //FIXME: Ought to work on collection classes too 
      if (coll[i].u.object->prog == Sequence_program) 
      { 
        ref_push_array(OBJ2_SEQUENCE(coll[i].u.object)->a); 
      } 
      else 
      { 
        SIMPLE_ARG_TYPE_ERROR("`+",i+1,"ADT.Sequence"); 
      } 
    } 
    f_add(args+1); 
    push_object(clone_object(Sequence_program, 1)); 
    stack_pop_n_elems_keep_top(args); 
  } 
 
 
/*! @decl Sequence `-(Sequence ... coll) 
 *! Subtraction operator 
 *! 
 *! Removes those values in this sequence that also are present in @@@[coll] 
 *! and return the results as a new @[Sequence]. 
 *! 
 *! @param coll 
 *!   The sequence to subtract from this sequence. 
 *! 
 *! @returns 
 *!   The result of the subtraction as a new @[Sequence]. 
 */ 
 
  PIKEFUN object `-(object ... coll) 
  { 
    int i; 
 
    ref_push_array(THIS->a); 
 
    for (i = 0; i < args; i++) { 
      //FIXME: Ought to work on collection classes too 
      if (coll[i].u.object->prog == Sequence_program) 
      { 
        ref_push_array(OBJ2_SEQUENCE(coll[i].u.object)->a); 
      } 
      else 
      { 
        SIMPLE_ARG_TYPE_ERROR("`-",i+1,"ADT.Sequence"); 
      } 
    } 
    f_minus(args+1); 
    push_object(clone_object(Sequence_program, 1)); 
    stack_pop_n_elems_keep_top(args); 
  } 
 
 
/*! @decl Sequence `&(Sequence coll) 
 *! And operator 
 *! Perform an and on this sequence and the @[coll] sequence by only returning 
 *! those values that is present in both sequences as a new @[Sequence]. 
 *! The remaining values is in the same order as they are in this sequence and 
 *! the values are compared using `==. 
 *! 
 *! @param coll 
 *!   The sequence to and to this sequence. 
 *! 
 *! @returns 
 *!   The result of the and as a new @[Sequence]. 
 */ 
 
  PIKEFUN object `&(object coll) 
  { 
    //Should work on collection classes too 
    if (coll->prog == Sequence_program) 
    { 
      push_array(and_arrays(THIS->a, 
                            OBJ2_SEQUENCE(coll)->a)); 
 
      push_object(clone_object(Sequence_program, 1)); 
    } 
    else 
    { 
      SIMPLE_ARG_TYPE_ERROR("`&",1,"ADT.Sequence"); 
    } 
  } 
 
 
/*! @decl Sequence `|(Sequence coll) 
 *! Or operator 
 *! Perform an or on this sequence and the @[coll] sequence by returning 
 *! those values that is present in both sequences as a new @[Sequence]. 
 *! The values are compared using `==. 
 *! 
 *! @param coll 
 *!   The sequence to or with this sequence. 
 *! 
 *! @returns 
 *!   The result of the or as a new @[Sequence]. 
 */ 
 
  PIKEFUN object `|(object coll) 
  { 
    //Should work on collection classes too 
    if (coll->prog == Sequence_program) 
    { 
      push_array(merge_array_with_order(THIS->a, 
                                        OBJ2_SEQUENCE(coll)->a, 
                                        PIKE_ARRAY_OP_OR)); 
 
      push_object(clone_object(Sequence_program, 1)); 
    } 
    else 
    { 
      SIMPLE_ARG_TYPE_ERROR("`|",1,"ADT.Sequence"); 
    } 
  } 
 
 
/*! @decl Sequence `^(Sequence coll) 
 *! Xor operator 
 *! Perform a xor on this sequence and the @[coll] sequence by returning 
 *! those values that is present in one of the sequences but not in both 
 *! adapters as a new @[Sequence]. 
 *! The values are compared using `==. 
 *! 
 *! @param coll 
 *!   The sequence to xor with this sequence. 
 *! 
 *! @returns 
 *!   The result of the xor as a new @[Sequence]. 
 */ 
 
  PIKEFUN object `^(object coll) 
  { 
    //Should work on collection classes too 
    if (coll->prog == Sequence_program) 
    { 
      push_array(merge_array_with_order(THIS->a, 
                                        OBJ2_SEQUENCE(coll)->a, 
                                        PIKE_ARRAY_OP_XOR)); 
 
      push_object(clone_object(Sequence_program, 1)); 
    } 
    else 
    { 
      SIMPLE_ARG_TYPE_ERROR("`^",1,"ADT.Sequence"); 
    } 
  } 
 
 
  /*! @decl int(0..1) _equal(mixed coll) 
   *! 
   *! @returns 
   *!   Returns @tt{true@} if the object @[coll] is a @[Sequence] 
   *!   and contains the same values in the same order. 
   */ 
 
  PIKEFUN int(0..1) _equal(mixed coll) 
  { 
    if (TYPEOF(*coll) == T_OBJECT && 
        coll->u.object->prog == Sequence_program) 
    { 
      struct Sequence_struct *adapter = OBJ2_SEQUENCE(coll->u.object); 
      RETURN  (array_equal_p(THIS->a, adapter->a, 0)); 
    } 
    RETURN 0; 
  } 
 
  /*! @decl array _indices() 
   *! 
   *! @returns 
   *!   The indices in this adapter as an array. 
   */ 
 
  PIKEFUN array _indices() 
  { 
    ptrdiff_t size = THIS->a->size; 
    struct array *a; 
 
    a=allocate_array_no_init(size,0); 
    while(--size>=0) 
    { 
      ITEM(a)[size].u.integer = (INT_TYPE)size; 
    } 
    a->type_field = BIT_INT; 
    RETURN a; 
  } 
 
/*! @decl void _insert_element(int index, mixed value) 
 *! Insert an element in the sequence at the position @[index], the value 
 *! at the position @[index] and all above will have their index increased 
 *! by one. 
 *! 
 *! @param index 
 *!   The index to insert the value at. 
 *! 
 *! @param value 
 *!   The new value. 
 *! 
 */ 
 
  PIKEFUN void _insert_element(int index, mixed value) 
  { 
    FIX_AND_CHECK_INDEX(index, THIS->a->size, 1); 
    should_copy(); 
    THIS->a = array_insert(THIS->a, value, index); 
 
  } 
 
/*! @decl mixed _remove_element(int index) 
 *!  Remove the values at index @[index] from the sequence. 
 *! 
 *! @param index 
 *!   The index to remove. 
 *! 
 *! @returns 
 *!   The removed value. 
 */ 
 
  PIKEFUN mixed _remove_element(int index) 
  { 
    struct svalue s; 
 
    FIX_AND_CHECK_INDEX(index, THIS->a->size, 0); 
 
    s = *(THIS->a->item + index); 
    should_copy(); 
    THIS->a = array_remove(THIS->a, index); 
    push_svalue(&s); 
  } 
 
 
/*! @decl int _search(mixed value, void|int start) 
 *!   Search the sequence for a specific value. Return the index of the first 
 *!   value that is equal to @[value]. If no value was found @expr{UNDEFINED@} 
 *!   is returned instead. 
 *! 
 *! @param value 
 *!   The value to find. 
 *! 
 *! @param start 
 *!   If a start value is supplied it will start searching at the index 
 *!   @[start]. 
 *! 
 *! @returns 
 *!   Returns the index of the found value or @expr{UNDEFINED@}. 
 */ 
 
  PIKEFUN int _search(mixed value, void|int start) 
  { 
    if(start) 
    { 
      if (TYPEOF(*start) != PIKE_T_INT) 
      { 
        SIMPLE_ARG_TYPE_ERROR("_search",2,"int"); 
      } 
      RETURN array_search(THIS->a, value, start->u.integer); 
    } 
    else 
    { 
      RETURN array_search(THIS->a,value,0); 
    } 
  } 
 
/*! @decl int _sizeof() 
 *! 
 *! @returns 
 *!   The number of elements in this adapter. 
 */ 
 
  PIKEFUN int _sizeof() 
  { 
    RETURN THIS->a->size; 
  } 
 
  /*! @decl array _values() 
   *! 
   *! @returns 
   *!   The values in this adapter as an array. 
   */ 
 
  PIKEFUN array _values() 
  { 
    struct array *a; 
     a=copy_array(THIS->a); 
    RETURN a; 
  } 
 
 
/*! @decl void add(mixed value) 
 *!   Add a value at the end of the sequence. 
 *! 
 *! @param value 
 *!   The value to add. 
 */ 
 
  PIKEFUN void add(mixed value) 
  { 
    should_copy(); 
    THIS->a=append_array(THIS->a, value); 
  } 
 
 
/*! @decl array cast(string type) 
 *! Cast operator. 
 *! 
 *! @param type 
 *!   Casts to this type. 
 *! 
 *!   Casts to the following types are supported: 
 *!   @string 
 *!     @value "array" 
 *!       Cast the content of this sequence to an array. 
 *!   @endstring 
 *! 
 *! @returns 
 *!   An array with the contents of this sequence. 
 */ 
 
  PIKEFUN array cast(string type) 
    flags ID_PROTECTED; 
  { 
    pop_n_elems(args); /* type as at least one more reference. */ 
    if (type == literal_array_string) 
      push_array(copy_array(THIS->a)); 
    else 
      push_undefined(); 
  } 
 
  /*! @decl void clear() 
   *!   Clear the contents of the sequence. 
   *! 
   */ 
 
  PIKEFUN void clear() 
  { 
    should_copy(); 
    THIS->a=resize_array(THIS->a, 0); 
  } 
 
  /*! @decl int delete_value(mixed value) 
   *!   Remove the first occurrence of the value @[value] from the sequence. 
   *! 
   *! @param value 
   *!   The value to remove from the sequence. 
   *! 
   *! @returns 
   *!   The index of the removed element or -1 if there was no value to 
   *!   remove. 
   */ 
 
  PIKEFUN int delete_value(mixed value) 
  { 
    INT32 index = array_search(THIS->a, value, 0); 
    if (index > -1) 
    { 
      should_copy(); 
      THIS->a = array_remove(THIS->a, index); 
    } 
    RETURN index; 
  } 
 
  /*! @decl int(0..1) is_empty() 
   *! 
   *! @returns 
   *!   Returns @expr{1@} if the sequence is empty otherwise @expr{0@}. 
   */ 
 
  PIKEFUN int(0..1) is_empty() 
  { 
    RETURN !(THIS->a->size); 
  } 
 
  /*! @decl int max_size() 
   *! 
   *! @returns 
   *!   Returns -1. 
   */ 
 
  PIKEFUN int max_size() 
  { 
    RETURN -1; 
  } 
 
 
  /*! @decl void create(array|int arg) 
   *!   Creates a new @[Sequence] around the array arg or a new 
   *!   @[Sequence] with the size of arg. 
   */ 
 
  PIKEFUN void create(array|int arg) 
  { 
    if (TYPEOF(*arg) == T_INT) 
    { 
      struct array *b = allocate_array_no_init(arg->u.integer, 0); 
      free_array(THIS->a); 
      THIS->a = b; 
      THIS->a->type_field = BIT_INT; 
    } 
    else if (TYPEOF(*arg) == T_ARRAY) 
    { 
      free_array(THIS->a); 
      add_ref(THIS->a=arg->u.array); 
    } 
  } 
 
 
 
  /*! @decl SequenceIterator _get_iterator(void|int ind) 
   *!   Create and initiate a new SequenceIterator that could be used 
   *!   to iterate over this sequence. 
   *! 
   *! @param ind 
   *!   If an @[ind] value is supplied the iterator will be positioned at 
   *!   that index. 
   *! 
   *! @returns 
   *!   An iterator. 
   */ 
 
 
 
  /*! @decl SequenceIterator first() 
   *!   Create and initiate a new SequenceIterator that could be used 
   *!   to iterate over this sequence. 
   *! 
   *! @returns 
   *!   An iterator positioned at the first element in the sequence. 
   */ 
 
 
  /*! @decl SequenceIterator last() 
   *!   Create and initiate a new SequenceIterator that could be used 
   *!   to iterate over this sequence. 
   *! 
   *! @returns 
   *!   An iterator positioned after the last element in the sequence. 
   */ 
 
 
  INIT 
  { 
    add_ref(THIS->a = &empty_array); 
    THIS->pos=0; 
  } 
 
  EXIT 
    gc_trivial; 
  { 
    free_array(THIS->a); 
  } 
 
  /*! @class SequenceIterator 
   *!    This is the iterator for the Sequence. It implements the 
   *!    IndexIterator and the OutputIterator 
   */ 
 
  PIKECLASS SequenceIterator 
  { 
    CVAR int pos; 
    CVAR struct Sequence_struct *sequence; 
    CVAR struct object *obj; 
 
 
  /*! @decl void create(object sequence, void|int start) 
   *!   Creates a new iterator for the sequence @[sequence]. If start is 
   *!   supplied it will try to position the iterator at @[start]. 
   *! 
   */ 
 
    PIKEFUN void create(object sequence, void|int start) 
    { 
 
      if (sequence->prog != Sequence_program) 
      { 
        SIMPLE_ARG_TYPE_ERROR("create",1,"ADT.Sequence"); 
      } 
      else 
      { 
        THIS->sequence = OBJ2_SEQUENCE(sequence); 
        add_ref(THIS->obj = sequence); 
        if (start) // if there was an start index supplied 
        { 
          THIS->pos=start->u.integer; 
          if (THIS->sequence->a && ((THIS->pos > THIS->sequence->a->size) 
                                   || (THIS->pos < 0))) 
          { 
              Pike_error("Index %d is out of array range 0 - %d.\n", 
                         THIS->pos, 
                         THIS->sequence->a->size); 
          } 
        } 
        else 
        { 
          THIS->pos = 0; 
        } 
      } 
 
    } 
 
    /*! @decl int index() 
     *! 
     *! @returns 
     *!    The index at the current position. 
     */ 
 
    PIKEFUN int index() 
    { 
      if(!THIS->sequence || 
         !THIS->sequence->a || 
         THIS->pos >= THIS->sequence->a->size) 
      { 
        push_undefined(); 
      } 
      else 
      { 
        RETURN THIS->pos; 
      } 
    } 
 
 
    /*! @decl mixed value() 
     *! 
     *! @returns 
     *!    The value at the current position. 
     */ 
 
    PIKEFUN mixed value() 
    { 
      if(!THIS->sequence || 
         !THIS->sequence->a || 
         THIS->pos >= THIS->sequence->a->size) 
      { 
        push_undefined(); 
      } 
      else 
      { 
        push_svalue(THIS->sequence->a->item + THIS->pos); 
      } 
    } 
 
 
    /*! @decl SequenceIterator `+(int steps) 
     *!   Move the iterator @[steps] steps forward (negative value on @[steps] 
     *!   will cause the iterator to move backwards) and return the result 
     *!   as a new iterator. 
     *! @returns 
     *!    A new iterator positioned @[steps] steps forward. 
     */ 
 
    PIKEFUN object `+(int steps) 
    { 
      struct object *o=fast_clone_object(Sequence_SequenceIterator_program); 
      struct Sequence_SequenceIterator_struct *new; 
      new = OBJ2_SEQUENCE_SEQUENCEITERATOR(o); 
      new[0]=*THIS; 
      add_ref(THIS->obj); 
      new->pos+=steps; 
      if (new->pos < 0) 
      { 
        new->pos = 0; 
      } 
      else if (new->pos > new->sequence->a->size) 
      { 
        new->pos = new->sequence->a->size; 
      } 
      RETURN o; 
    } 
 
    /*! @decl SequenceIterator `+=(int steps) 
     *!   Move this iterator @[steps] steps forward (negative value on @[steps] 
     *!   will cause the iterator to move backwards) and return the result. 
     *! 
     *! @returns 
     *!    This iterator positioned @[steps] steps forward. 
     */ 
 
 
    PIKEFUN object `+=(int steps) 
    { 
      THIS->pos+=steps; 
      if (THIS->pos < 0) 
      { 
        THIS->pos = 0; 
      } 
      else if (THIS->pos > THIS->sequence->a->size) 
      { 
        THIS->pos = THIS->sequence->a->size; 
      } 
 
      REF_RETURN Pike_fp->current_object; 
    } 
 
 
    /*! @decl SequenceIterator `-(int steps) 
     *!   Move the iterator @[steps] steps backwards (negative value on 
     *!   @[steps] will cause the iterator to move forwards) and return 
     *!   the result as a new iterator. 
     *! @returns 
     *!    A new iterator positioned @[steps] steps backwards. 
     */ 
 
    PIKEFUN object `-(int steps) 
    { 
      struct object *o=fast_clone_object(Sequence_SequenceIterator_program); 
      struct Sequence_SequenceIterator_struct *new; 
      new = OBJ2_SEQUENCE_SEQUENCEITERATOR(o); 
      new[0]=*THIS; 
      add_ref(THIS->obj); 
      new->pos-=steps; 
      if (new->pos < 0) 
      { 
        new->pos = 0; 
      } 
      else if (new->pos > new->sequence->a->size) 
      { 
        new->pos = new->sequence->a->size; 
      } 
      RETURN o; 
    } 
 
 
    /*! @decl int(0..1) has_next(void|int steps) 
     *! @returns 
     *!    Returns @tt{true@} if it is possible to move @[steps] steps 
     *!    forwards, if @[steps] weren't supplied it check if it is 
     *!    possible to move one step forward. 
     */ 
 
    PIKEFUN int(0..1) has_next(void|int steps) 
    { 
      if (!steps) 
      { 
        RETURN (THIS->sequence && THIS->sequence->a && 
                (THIS->pos + 1) <= THIS->sequence->a->size); 
      } 
      else 
      { 
        RETURN (THIS->sequence && THIS->sequence->a && 
                (THIS->pos + steps->u.integer) >= 0 && 
                (THIS->pos + steps->u.integer) <= THIS->sequence->a->size); 
      } 
    } 
 
 
    /*! @decl int(0..1) has_previous(void|int steps) 
     *! @returns 
     *!    Returns @tt{true@} if it is possible to move @[steps] steps 
     *!    backwards, if @[steps] weren't supplied it check if it is 
     *!    possible to move one step backward. 
     */ 
 
    PIKEFUN int(0..1) has_previous(void|int steps) 
    { 
      if (!steps) 
      { 
        RETURN (THIS->sequence && THIS->sequence->a && 
                (THIS->pos) > 0); 
      } 
      else 
      { 
        RETURN (THIS->sequence && THIS->sequence->a && 
                (THIS->pos - steps->u.integer) >= 0 && 
                (THIS->pos - steps->u.integer) <= THIS->sequence->a->size); 
      } 
    } 
 
 
    /*! @decl int(0..1) `!() 
     *! @returns 
     *!    Returns @tt{false@} if the iterator has reached the end. 
     */ 
 
    PIKEFUN int(0..1) `!() 
    { 
      RETURN (THIS->sequence && THIS->sequence->a && 
              THIS->pos  == THIS->sequence->a->size); 
    } 
 
 
    /*! @decl int(0..1) _equal(mixed iter) 
     *!    Compare this iterator with another iterator. 
     *! 
     *! @param iter 
     *!    The iterator to compare with. 
     *! @returns 
     *!    Returns @tt{true@} if both iterators iterates over the same 
     *!    objects and are positioned at the same spot. 
     */ 
 
    PIKEFUN int(0..1) _equal(mixed iter) 
    { 
      if (TYPEOF(*iter) == T_OBJECT && 
          iter->u.object->prog == Sequence_SequenceIterator_program) 
      { 
        //to do: Check so that it is an SequenceIterator 
        struct Sequence_SequenceIterator_struct *i = 
          OBJ2_SEQUENCE_SEQUENCEITERATOR(iter->u.object); 
        RETURN (THIS->sequence == i->sequence && THIS->pos == i->pos); 
      } 
      else 
      { 
        RETURN 0; 
      } 
    } 
 
 
    /*! @decl int(0..1) `<(mixed iter) 
     *!    Less then operator. 
     *! 
     *! @returns 
     *!    Returns @tt{true@} if this iterator has a lower index 
     *!    then @[iter]. 
     */ 
 
    PIKEFUN int(0..1) `<(mixed iter) 
    { 
      if (TYPEOF(*iter) == T_OBJECT && 
          iter->u.object->prog == Sequence_SequenceIterator_program) 
      { 
        //to do: Check so that it is an SequenceIterator 
        struct Sequence_SequenceIterator_struct *i = 
          OBJ2_SEQUENCE_SEQUENCEITERATOR(iter->u.object); 
        RETURN (THIS->pos < i->pos); 
      } 
      else 
      { 
        SIMPLE_ARG_TYPE_ERROR("`<",1,"ADT.Sequence.SequenceIterator"); 
      } 
    } 
 
 
    /*! @decl int(0..1) `>(mixed iter) 
     *!    Greater then operator. 
     *! 
     *! @returns 
     *!    Returns @tt{true@} if this iterator has a higher index 
     *!    then @[iter]. 
     */ 
 
 
    PIKEFUN int(0..1) `>(mixed iter) 
    { 
      if (TYPEOF(*iter) == T_OBJECT && 
          iter->u.object->prog == Sequence_SequenceIterator_program) 
      { 
        //to do: Check so that it is an SequenceIterator 
        struct Sequence_SequenceIterator_struct *i = 
          OBJ2_SEQUENCE_SEQUENCEITERATOR(iter->u.object); 
        RETURN (THIS->pos > i->pos); 
      } 
      else 
      { 
        SIMPLE_ARG_TYPE_ERROR("`>",1,"ADT.Sequence.SequenceIterator"); 
      } 
    } 
 
 
    /*! @decl int distance(object iter) 
     *! 
     *! @param iter 
     *!    The iterator to measure the distance to. 
     *! @returns 
     *!    Returns distance between this iterator and @[iter]. 
     *! @throws 
     *!    An error if the two iterator could not be compared. 
     */ 
 
    PIKEFUN int distance(object iter) 
    { 
      if (iter->prog == Sequence_SequenceIterator_program) 
      { 
 
        struct Sequence_SequenceIterator_struct *i = 
          OBJ2_SEQUENCE_SEQUENCEITERATOR(iter); 
        RETURN (i->pos - THIS->pos); 
      } 
      else 
      { 
        SIMPLE_ARG_TYPE_ERROR("distance",1,"ADT.Sequence.SequenceIterator"); 
      } 
    } 
 
    /*! @decl Sequence get_collection() 
     *! 
     *! @returns 
     *!    Returns the Sequence this iterator currently iterates over. 
     */ 
 
 
    PIKEFUN object get_collection() 
    { 
      REF_RETURN THIS->obj; 
    } 
 
 
    /*! @decl mixed set_value(mixed val) 
     *!    Set the value at the current position. 
     *! 
     *! @param val 
     *!    The new value. 
     *! @returns 
     *!    Returns the old value. 
     */ 
 
 
    PIKEFUN mixed set_value(mixed val) 
    { 
      if (THIS->sequence && THIS->sequence->a && 
          THIS->pos < THIS->sequence->a->size) 
      { 
        struct svalue ind; 
        struct svalue retval; 
 
        //if there is someone else using the array but the adapter 
        if (THIS->sequence->a->refs > 1) 
        { 
          //copy it 
          free_array(THIS->sequence->a); 
          THIS->sequence->a = copy_array(THIS->sequence->a); 
        } 
 
        SET_SVAL(ind, T_INT, NUMBER_NUMBER, integer, THIS->pos); 
        simple_array_index_no_free(&retval, THIS->sequence->a, &ind); 
        simple_set_index(THIS->sequence->a, &ind, val); 
        push_svalue(&retval); 
      } 
      else 
      { 
        push_undefined(); 
      } 
    } 
 
    INIT 
    { 
      THIS->sequence=0; 
      THIS->pos=0; 
      THIS->obj = NULL; 
    } 
 
    EXIT 
      gc_trivial; 
    { 
      if( THIS->obj ) 
      { 
        free_object(THIS->obj); 
        THIS->obj = NULL; 
      } 
    } 
 
  } 
 
  //End SequenceIterator 
  /*! @endclass 
  */ 
 
  PIKEFUN object _get_iterator(void|int ind) 
  { 
    ref_push_object(Pike_fp->current_object); 
    if (ind) 
    { 
      push_svalue(ind); 
    } 
    push_object(clone_object(Sequence_SequenceIterator_program, args+1)); 
  } 
 
 
 
  PIKEFUN object first() 
  { 
    ref_push_object(Pike_fp->current_object); 
    push_object(clone_object(Sequence_SequenceIterator_program, 1)); 
  } 
 
 
 
  PIKEFUN object last() 
  { 
    struct svalue ind; 
    SET_SVAL(ind, T_INT, NUMBER_NUMBER, integer, THIS_SEQUENCE->a->size); 
    ref_push_object(Pike_fp->current_object); 
    push_svalue(&ind); 
    push_object(clone_object(Sequence_SequenceIterator_program, 2)); 
  } 
 
 
} 
 
 
//End of Sequence 
/*! @endclass 
  */ 
 
/*! @endmodule 
 */ 
 
 
void pike_init_Sequence_module(void) 
{ 
  INIT; 
} 
 
void pike_exit_Sequence_module(void) 
{ 
  EXIT 
}