SQLite

** Bit 0x20 is set if the mapped character requires translation to upper
** case. i.e. if the character is a lower-case ASCII character.
** If x is a lower-case ASCII character, then its upper-case equivalent
** is (x - 0x20). Therefore toupper() can be implemented as:
**
**   (x & ~(map[x]&0x20))
**
** Standard function tolower() is implemented using the sqlite3UpperToLower[]
** array. tolower() is used more often than toupper() by SQLite.
**
** Bit 0x40 is set if the character non-alphanumeric and can be used in an 
** SQLite identifier.  Identifiers are alphanumerics, "_", "$", and any
** non-ASCII UTF character. Hence the test for whether or not a character is
** part of an identifier is 0x46.
**
** SQLite's versions are identical to the standard versions assuming a
** locale of "C". They are implemented as macros in sqliteInt.h.
*/
#ifdef SQLITE_ASCII
const unsigned char sqlite3CtypeMap[256] = {
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 00..07    ........ */
  0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00,  /* 08..0f    ........ */
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 10..17    ........ */
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 18..1f    ........ */

** page size in bytes.
*/
#ifndef SQLITE_SORTER_PMASZ
# define SQLITE_SORTER_PMASZ 250
#endif

/* Statement journals spill to disk when their size exceeds the following
** threashold (in bytes). 0 means that statement journals are created and
** written to disk immediately (the default behavior for SQLite versions
** before 3.12.0).  -1 means always keep the entire statement journal in
** memory.  (The statement journal is also always held entirely in memory
** if journal_mode=MEMORY or if temp_store=MEMORY, regardless of this
** setting.)
*/
#ifndef SQLITE_STMTJRNL_SPILL 

};


/*
** The value of the "pending" byte must be 0x40000000 (1 byte past the
** 1-gibabyte boundary) in a compatible database.  SQLite never uses
** the database page that contains the pending byte.  It never attempts
** to read or write that page.  The pending byte page is set assign
** for use by the VFS layers as space for managing file locks.
**
** During testing, it is often desirable to move the pending byte to
** a different position in the file.  This allows code that has to
** deal with the pending byte to run on files that are much smaller
** than 1 GiB.  The sqlite3_test_control() interface can be used to
** move the pending byte.

** Boolean values
*/
typedef unsigned Bool;

/* Opaque type used by code in vdbesort.c */
typedef struct VdbeSorter VdbeSorter;

/* Opaque type used by the explainer */
typedef struct Explain Explain;

/* Elements of the linked list at Vdbe.pAuxData */
typedef struct AuxData AuxData;

/* Types of VDBE cursors */
#define CURTYPE_BTREE       0
#define CURTYPE_SORTER      1
#define CURTYPE_VTAB        2

  u32 *aOffset;         /* Pointer to aType[nField] */
  u32 aType[1];         /* Type values for all entries in the record */
  /* 2*nField extra array elements allocated for aType[], beyond the one
  ** static element declared in the structure.  nField total array slots for
  ** aType[] and nField+1 array slots for aOffset[] */
};







/*
** When a sub-program is executed (OP_Program), a structure of this type
** is allocated to store the current value of the program counter, as
** well as the current memory cell array and various other frame specific
** values stored in the Vdbe struct. When the sub-program is finished, 
** these values are copied back to the Vdbe from the VdbeFrame structure,
** restoring the state of the VM to as it was before the sub-program

  int nChildCsr;          /* Number of cursors for child frame */
  int nChange;            /* Statement changes (Vdbe.nChange)     */
  int nDbChange;          /* Value of db->nChange */
};

#define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))])

/*
** A value for VdbeCursor.cacheValid that means the cache is always invalid.
*/
#define CACHE_STALE 0

/*
** Internally, the vdbe manipulates nearly all SQL values as Mem
** structures. Each Mem struct may cache multiple representations (string,
** integer etc.) of the same value.
*/
struct Mem {
  union MemValue {

  int isError;            /* Error code returned by the function. */
  u8 skipFlag;            /* Skip accumulator loading if true */
  u8 fErrorOrAux;         /* isError!=0 or pVdbe->pAuxData modified */
  u8 argc;                /* Number of arguments */
  sqlite3_value *argv[1]; /* Argument set */
};

/*
** An Explain object accumulates indented output which is helpful
** in describing recursive data structures.
*/
struct Explain {
  Vdbe *pVdbe;       /* Attach the explanation to this Vdbe */
  StrAccum str;      /* The string being accumulated */
  int nIndent;       /* Number of elements in aIndent */
  u16 aIndent[100];  /* Levels of indentation */
  char zBase[100];   /* Initial space */
};

/* A bitfield type for use inside of structures.  Always follow with :N where
** N is the number of bits.
*/
typedef unsigned bft;  /* Bit Field Type */

typedef struct ScanStatus ScanStatus;
struct ScanStatus {