// Puts the given token at the end of the stream.
inline void
Token_stream::put(Token tok)
{
buf_.push_back(tok);
// Make sure that the pos_ isn't pointing past
// then end after insertion into an empty list.
if (pos_ == buf_.end())
pos_ = buf_.begin();
}
// Returns the nth token past the current position.
inline Token
Token_stream::peek(int n) const
{
// Get the nth token, but restore the stream position
// afterwards. Note that this will gracefully handle
// an eof during lookahead.
Position i = pos_;
while (i != buf_.end() && n) {
++i;
--n;
}
if (i == buf_.end())
return Token();
else
return *i;
}
// Returns true if the stream is at the end of the file.
inline bool
Token_stream::eof() const
{
return pos_ == buf_.end();
}
// Initialize a token stream with an empty
// buffer.
inline
Token_stream::Token_stream()
: buf_(), pos_(buf_.begin())
{ }
