package gnu.q2.lang;import gnu.kawa.lispexpr.*;import gnu.expr.QuoteExp;import gnu.text.*;import gnu.mapping.*;import gnu.lists.*;import gnu.expr.Keyword;import gnu.kawa.xml.MakeAttribute;/** A class to read Scheme forms (S-expressions). */public class Q2Read extends LispReader{  void init()  {    initialColonIsKeyword = false;    ((InPort) port).readState = ' ';  }  public Q2Read(InPort port)  {    super(port);    init();  }    public Q2Read(InPort port, SourceMessages messages)  {    super(port, messages);    init();  }    int skipIndentation ()      throws java.io.IOException, SyntaxException  {    int numTabs = 0, numSpaces = 0;    int ch = port.read();    while (ch == '\t')      {	numTabs++;	ch = port.read();      }    while (ch == ' ')      {	numSpaces++;	ch = port.read();      }    if (ch < 0)      return -1;    port.unread();    return (numTabs << 16) + numSpaces;  }  boolean singleLine()  {    return interactive && nesting == 0;  }  public Object readCommand ()      throws java.io.IOException, SyntaxException  {    return readCommand(false);  }  public Object readCommand (boolean forceList)      throws java.io.IOException, SyntaxException  {    int line = port.getLineNumber();    int startColumn = port.getColumnNumber();    int lastColumn = startColumn;    Object obj = LList.Empty;    PairWithPosition pair = null, last = null;    for (;;)      {	int ch = read();	if (ch < 0)	  break;	if (ch == ' ' || ch == '\t')	  continue;	unread();	if (ch == ')')	  break;	line = port.getLineNumber();	int column = port.getColumnNumber();	while (ch == '\r' || ch == '\n')	  {	    if (singleLine())	      return obj;	    ch = read();	    skipIndentation(); // skipHorSpace.	    column = port.getColumnNumber();	    ch = peek();	    if (column <= startColumn)	      break;	  }	if (column <= startColumn && last != null)	  break;	Object next;	if (column == lastColumn && last != null)	  next = readCommand();	else if (column < lastColumn && last != null)	  {	    PairWithPosition p = pair;	    for (;;)	      {		Object n = p.cdr;		if (n == LList.Empty)		  break;		PairWithPosition np = (PairWithPosition) n;		int pColumn = np.getColumnNumber()-1;		if (pColumn >= column)		  {		    if (pColumn > column)		      error('e', "some tokens on previous line indented more than current line");		    n = np.cdr;		    if (n != LList.Empty)		      {			if (((PairWithPosition) n).getColumnNumber()-1==column)			  {			    p = (PairWithPosition) n;			    continue;			  }			last = (PairWithPosition)			  makePair(np, port.getLineNumber(), column);			p.cdr = last;		      }		    break;		  }		p = np;	      }	    next = readCommand();	  }	else	  next = readObject();	if (next == Sequence.eofValue)	  break;	lastColumn = column;	String filename = port.getName();	PairWithPosition cur = PairWithPosition.make(next, LList.Empty,						     filename, line+1, column+1);	if (last == null)	  {	    pair = cur;	    obj = cur;	  }	else if (last.car instanceof Keyword)	  {	    Object name = new QuoteExp(((Keyword) last.car).getName());	    last.car	      = new PairWithPosition(last, MakeAttribute.makeAttribute,				     new PairWithPosition(last, name, cur));	    continue;	  }	else	  last.cdr = cur;	last = cur;      }    if (! forceList)      {	if (obj == last)	  obj = last.car;	else if (last == null)	  obj = QuoteExp.voidExp;      }    return obj;  }  public static Object readObject(InPort port)      throws java.io.IOException, SyntaxException  {    return (new Q2Read(port)).readObject();  }  /** Record '[' location for error messages. */   String expressionStartFile;  int expressionStartLine;  int expressionStartColumn;  void saveExpressionStartPosition()  {    expressionStartFile = port.getName();    expressionStartLine = port.getLineNumber();    expressionStartColumn = port.getColumnNumber();  }}class Q2ReaderParens extends ReaderDispatchMisc{  public Object read (Lexer in, int ch, int count)    throws java.io.IOException, SyntaxException  {    Q2Read reader = (Q2Read) in;    char saveReadState = reader.pushNesting('(');    try      {	Object result = reader.readCommand(true);	LineBufferedReader port = reader.getPort();	if (port.read() != ')')	  reader.error("missing ')'");	return result;      }    finally      {	reader.popNesting(saveReadState);      }  }}