text: /* table.h: Interface for a dictionary
   *
   * $Id$
   * Copyright (c) 2001-2020 Ravenbrook Limited.  See end of file for license.
   *
   * A table is a hashed mapping from keys to values.
   */
  
  #ifndef table_h
  #define table_h
  
  #include "mpmtypes.h"
  #include <stddef.h>
  
  
  typedef struct TableStruct *Table;
  
  typedef Word TableKey;
  typedef void *TableValue;
  
  typedef struct TableEntryStruct {
    TableKey key;
    TableValue value;
  } TableEntryStruct, *TableEntry;
  
  typedef void *(*TableAllocFunction)(void *closure, size_t size);
  typedef void (*TableFreeFunction)(void *closure, void *p, size_t size);
  
  #define TableSig        ((Sig)0x5192AB13) /* SIGnature TABLE */
  
  typedef struct TableStruct {
    Sig sig;                      /* <design/sig> */
    Count length;                 /* Number of slots in the array */
    Count count;                  /* Active entries in the table */
    TableEntry array;             /* Array of table slots */
    TableAllocFunction alloc;
    TableFreeFunction free;
    void *allocClosure;
    TableKey unusedKey;           /* key marking unused (undefined) entries */
    TableKey deletedKey;          /* key marking deleted entries */
  } TableStruct;
  
  extern Res TableCreate(Table *tableReturn,
                         Count length,
                         TableAllocFunction tableAlloc,
                         TableFreeFunction tableFree,
                         void *allocClosure,
                         TableKey unusedKey,
                         TableKey deletedKey);
  extern void TableDestroy(Table table);
  extern Bool TableCheck(Table table);
  extern Res TableDefine(Table table, TableKey key, TableValue value);
  extern Res TableRedefine(Table table, TableKey key, TableValue value);
  extern Bool TableLookup(TableValue *valueReturn, Table table, TableKey key);
  extern Res TableRemove(Table table, TableKey key);
  extern Count TableCount(Table table);
  extern void TableMap(Table table,
                       void(*fun)(void *closure, TableKey key, TableValue value),
                       void *closure);
  extern Res TableGrow(Table table, Count extraCapacity);
  
  
  #endif /* table_h */
  
  
  /* C. COPYRIGHT AND LICENSE
   *
   * Copyright (C) 2001-2020 Ravenbrook Limited <https://www.ravenbrook.com/>.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the
   *    distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
   * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
   * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  