! --------------------------------------------------------------
! Dunno - A Libary Extension by Neil Cerutti (cerutti@together.net)
! Version 1.0 - 25 Jun 1999
!   Initial release
! Version 1.1 - 2 Apr 2001
!   Modified by Andrew Plotkin for Glulx compatibility.
!
! If, for some reason, you always wanted the Infocom-style error
! messages that say:
!
!  I don't know the word "kludge".
!
! here's one way to do it.
!
! To use this file, put the command
!
!   Include "dunno.h";
!
! somewhere in your program's source code.
!
! The DontKnowError() routine must be called from within your
! program in one of the following two ways:
!
! 1. in the ParserError entry point [Inform Designer's Manual, 
!    Graham Nelson, Section 29]. For example:
!
!   [ ParserError pe; 
!     if (pe == CANTSEE_PE) return DontKnowError(); 
!     rfalse;
!   ];
!
! or
!
! 2. in the LibraryMessages object [Nelson, Section 21]. For example:
!
!   Object LibraryMessages with before [; 
!     Miscellany: if (lm_n == 30) return DontKnowError(); 
!   ];
!
! If you need help getting this to work, or just have comments or
! suggestions, write me at cerutti@together.net.
! ---------------------------------------------------------------

! Check for an unknown word in the input starting at word 2. If one 
! is found, print "I don't know the word ~xxx~." and return true. 
! Otherwise, return false.
[ DontKnowError 
  wordnum;
  wordnum=FindUnknownWordToken(2);
  if (wordnum ~= 0)
  { print "I don't know the word ~"; 
    PrintToken(wordnum);
    "~."; 
  } 
  else rfalse; 
];

! Find the word number of the word in the input that is an 
! unknown word, starting at wordnum, and return it. If no unknown 
! word is found, return false.
!
! An unknown word is defined: An item that is not in the 
! dictionary and not a number. 
[ FindUnknownWordToken wordnum 
  w twn numwds;
#ifdef TARGET_GLULX;
  numwds = parse-->0;
#ifnot;
  numwds = parse->1;
#endif; ! TARGET_GLULX;
  ! Throw out invalid word numbers
  if (wordnum <= 0 || wordnum > numwds) rfalse;
  twn=wn; ! save the value of wn so it can be restored
  wn=wordnum;
  while (1)
  { w=NextWordStopped();
    if (w == -1) { wn=twn; rfalse; }
    if (w == 0 && TryNumber(wn-1) == -1000) 
    { wordnum=wn-1;
      wn=twn;
      return wordnum; 
    }
  }
];

! Print the exact text in the input at wordnum.
[ PrintToken wordnum 
  k l m numwds;
#ifdef TARGET_GLULX;
  numwds = parse-->0;
#ifnot;
  numwds = parse->1;
#endif; ! TARGET_GLULX;
  if (wordnum <= 0 || wordnum > numwds) return;
  k=WordAddress(wordnum); 
  l=WordLength(wordnum); 
  for (m=0: m < l: m++) 
    print (char) k->m; 
];

! ---------------------------------------------------------------