{$I   "Include:Exec/Nodes.i"}

{   *********************************************************************
 *
 * The CSource data structure defines the input source for "ReadItem()"
 * as well as the ReadArgs call.  It is a publicly defined structure
 * which may be used by applications which use code that follows the
 * conventions defined for access.
 *
 * When passed to the dos.library functions, the value passed as
 * struct *CSource is defined as follows:
 *      if ( CSource == 0)      Use buffered IO "ReadChar()" as data source
 *      else                    Use CSource for input character stream
 *
 * The following two pseudo-code routines define how the CSource structure
 * is used:
 *
 * long CS_ReadChar( struct CSource *CSource )
 *
 *      if ( CSource == 0 )     return ReadChar();
 *      if ( CSource->CurChr >= CSource->Length )       return ENDSTREAMCHAR;
 *      return CSource->Buffer[ CSource->CurChr++ ];
 *
 *
 * BOOL CS_UnReadChar( struct CSource *CSource )
 *
 *      if ( CSource == 0 )     return UnReadChar();
 *      if ( CSource->CurChr <= 0 )     return FALSE;
 *      CSource->CurChr--;
 *      return TRUE;
 *
 *
 * To initialize a struct CSource, you set CSource->CS_Buffer to
 * a string which is used as the data source, and set CS_Length to
 * the number of characters in the string.  Normally CS_CurChr should
 * be initialized to ZERO, or left as it was from prior use as
 * a CSource.
 *
 *********************************************************************}

Type
       CSource = Record
        CS_Buffer  : String;
        CS_Length,
        CS_CurChr  : Integer;
       END;
       CSourcePtr = ^CSource;

{   *********************************************************************
 *
 * The RDArgs data structure is the input parameter passed to the DOS
 * ReadArgs() function call.
 *
 * The RDA_Source structure is a CSource as defined above;
 * if RDA_Source.CS_Buffer is non-null, RDA_Source is used as the input
 * character stream to parse, else the input comes from the buffered STDIN
 * calls ReadChar/UnReadChar.
 *
 * RDA_DAList is a private address which is used internally to track
 * allocations which are freed by FreeArgs().  This MUST be initialized
 * to NULL prior to the first call to ReadArgs().
 *
 * The RDA_Buffer and RDA_BufSiz fields allow the application to supply
 * a fixed-size buffer in which to store the parsed data.  This allows
 * the application to pre-allocate a buffer rather than requiring buffer
 * space to be allocated.  If either RDA_Buffer or RDA_BufSiz is NULL,
 * the application has not supplied a buffer.
 *
 * RDA_ExtHelp is a text string which will be displayed instead of the
 * template string, if the user is prompted for input.
 *
 * RDA_Flags bits control how ReadArgs() works.  The flag bits are
 * defined below.  Defaults are initialized to ZERO.
 *
 *********************************************************************}

       RDArgs = Record
        RDA_Source  : CSource;     {    Select input source }
        RDA_DAList  : Integer;             {    PRIVATE. }
        RDA_Buffer  : String;            {    Optional string parsing space. }
        RDA_BufSiz  : Integer;             {    Size of RDA_Buffer (0..n) }
        RDA_ExtHelp : String;           {    Optional extended help }
        RDA_Flags   : Integer;              {    Flags for any required control }
       END;
       RDArgsPtr = ^RDArgs;

CONST
       RDAB_STDIN     = 0;       {    Use "STDIN" rather than "COMMAND LINE" }
       RDAF_STDIN     = 1;
       RDAB_NOALLOC   = 1;       {    If set, do not allocate extra string space.}
       RDAF_NOALLOC   = 2;
       RDAB_NOPROMPT  = 2;       {    Disable reprompting for string input. }
       RDAF_NOPROMPT  = 4;

{   *********************************************************************
 * Maximum number of template keywords which can be in a template passed
 * to ReadArgs(). IMPLEMENTOR NOTE - must be a multiple of 4.
 *********************************************************************}
       MAX_TEMPLATE_ITEMS     = 100;

{   *********************************************************************
 * Maximum number of MULTIARG items returned by ReadArgs(), before
 * an ERROR_LINE_TOO_LONG.  These two limitations are due to stack
 * usage.  Applications should allow "a lot" of stack to use ReadArgs().
 *********************************************************************}
       MAX_MULTIARGS          = 128;


FUNCTION FindArgs(Template, KeyWord : String) : Integer;
    External;

PROCEDURE FreeArgs(Args : RDArgsPtr);
    External;

FUNCTION ReadArgs(template : String; Buffer : Address; RD : RDArgsPtr) : RDArgsPtr;
    External;

FUNCTION ReadItem(buffer : String; BufferSize : Integer; CS : CSourcePtr) : Integer;
    External;