override public Token token()
{
for (;;)
{
/* Deal with lexed tokens first. */
if (arg != null)
{
if (arg.hasNext())
{
Token tok2 = arg.next();
/* XXX PASTE -> INVALID. */
Debug.Assert(tok2.getType() != Token.M_PASTE,
"Unexpected paste token");
return(tok2);
}
arg = null;
}
if (!tokens.hasNext())
{
return(new Token(Token.EOF, -1, -1, "")); /* End of macro. */
}
Token tok = tokens.next();
int idx;
switch (tok.getType())
{
case Token.M_STRING:
/* Use the nonexpanded arg. */
idx = (int)tok.getValue();
return(stringify(tok, args.get(idx)));
case Token.M_ARG:
/* Expand the arg. */
idx = (int)tok.getValue();
// System.out.println("Pushing arg " + args.get(idx));
arg = args.get(idx).expansion();
break;
case Token.M_PASTE:
paste(tok);
break;
default:
return(tok);
}
} /* for */
}
/* At this point, we have consumed the first M_PASTE.
* @see Macro#addPaste(Token) */
private void paste(Token ptok)
{
StringBuilder buf = new StringBuilder();
Token err = null;
/* We know here that arg is null or expired,
* since we cannot paste an expanded arg. */
int count = 2;
for (int i = 0; i < count; i++)
{
if (!tokens.hasNext())
{
/* XXX This one really should throw. */
error(ptok.getLine(), ptok.getColumn(),
"Paste at end of expansion");
buf.append(' ').append(ptok.getText());
break;
}
Token tok = tokens.next();
// System.out.println("Paste " + tok);
switch (tok.getType())
{
case Token.M_PASTE:
/* One extra to paste, plus one because the
* paste token didn't count. */
count += 2;
ptok = tok;
break;
case Token.M_ARG:
int idx = (int)tok.getValue();
concat(buf, args.get(idx));
break;
/* XXX Test this. */
case Token.CCOMMENT:
case Token.CPPCOMMENT:
break;
default:
buf.append(tok.getText());
break;
}
}
/* Push and re-lex. */
/*
* StringBuilder src = new StringBuilder();
* escape(src, buf);
* StringLexerSource sl = new StringLexerSource(src.toString());
*/
StringLexerSource sl = new StringLexerSource(buf.toString());
/* XXX Check that concatenation produces a valid token. */
arg = new SourceIterator(sl);
}