input.cc

早期freebsd实现

      {
	unsigned char ch = tok.c;
	if (bol && 
	    (ch == curenv->control_char
	     || ch == curenv->no_break_control_char)) {
	  break_flag = ch == curenv->control_char;
	  // skip tabs as well as spaces here
	  do {
	    tok.next();
	  } while (tok.white_space());
	  symbol nm = get_name();
	  if (nm.is_null())
	    skip_line();
	  else
	    interpolate_macro(nm);
	  suppress_next = 1;
	}
	else {
	  if (possibly_handle_first_page_transition())
	    ;
	  else {
	    for (;;) {
	      curenv->add_char(charset_table[ch]);
	      tok.next();
	      if (tok.type != token::TOKEN_CHAR)
		break;
	      ch = tok.c;
	    }
	    suppress_next = 1;
	    bol = 0;
	  }
	}
	break;
      }
    case token::TOKEN_TRANSPARENT:
      {
	if (bol) {
	  if (possibly_handle_first_page_transition())
	    ;
	  else {
	    int cc;
	    do {
	      node *n;
	      cc = get_copy(&n);
	      if (cc != EOF)
		if (cc != '\0')
		  curdiv->transparent_output(transparent_translate(cc));
		else
		  curdiv->transparent_output(n);
	    } while (cc != '\n' && cc != EOF);
	    if (cc == EOF)
	      curdiv->transparent_output('\n');
	  }
	}
	break;
      }
    case token::TOKEN_NEWLINE:
      {
	if (bol && !curenv->get_prev_line_interrupted())
	  blank_line();
	else {
	  curenv->newline();
	  bol = 1;
	}
	break;
      }
    case token::TOKEN_REQUEST:
      {
	int request_code = tok.c;
	tok.next();
	switch (request_code) {
	case TITLE_REQUEST:
	  title();
	  break;
	case COPY_FILE_REQUEST:
	  copy_file();
	  break;
	case TRANSPARENT_FILE_REQUEST:
	  transparent_file();
	  break;
#ifdef COLUMN
	case VJUSTIFY_REQUEST:
	  vjustify();
	  break;
#endif /* COLUMN */
	default:
	  assert(0);
	  break;
	}
	suppress_next = 1;
	break;
      }
    case token::TOKEN_SPACE:
      {
	if (possibly_handle_first_page_transition())
	  ;
	else if (bol && !curenv->get_prev_line_interrupted()) {
	  int nspaces = 0;
	  do {
	    nspaces += tok.nspaces();
	    tok.next();
	  } while (tok.space());
	  if (tok.newline())
	    blank_line();
	  else {
	    push_token(tok);
	    curenv->do_break();
	    curenv->add_node(new hmotion_node(curenv->get_space_width()*nspaces));
	    bol = 0;
	  }
	}
	else {
	  curenv->space();
	  bol = 0;
	}
	break;
      }
    case token::TOKEN_EOF:
      return;
    case token::TOKEN_NODE:
      {
	if (possibly_handle_first_page_transition())
	  ;
	else if (tok.nd->reread(&bol)) {
	  delete tok.nd;
	  tok.nd = 0;
	}
	else {
	  curenv->add_node(tok.nd);
	  tok.nd = 0;
	  bol = 0;
	}
	break;
      }
    case token::TOKEN_PAGE_EJECTOR:
      {
	continue_page_eject();
	// I think we just want to preserve bol.
	// bol = 1;
	break;
      }
    case token::TOKEN_BEGIN_TRAP:
      {
	trap_bol_stack.push(bol);
	bol = 1;
	break;
      }
    case token::TOKEN_END_TRAP:
      {
	if (trap_bol_stack.is_empty())
	  error("spurious end trap token detected!");
	else
	  bol = trap_bol_stack.pop();

	/* I'm not totally happy about this.  But I can't think of any other
	  way to do it.  Doing an output_pending_lines() whenever a
	  TOKEN_END_TRAP is detected doesn't work: for example,

          .wh -1i x
          .de x
          'bp
	  ..
	  .wh -.5i y
	  .de y
	  .tl ''-%-''
	  ..
	  .br
	  .ll .5i
	  .sp |\n(.pu-1i-.5v
	  a\%very\%very\%long\%word

          will print all but the first lines from the word immediately
          after the footer, rather than on the next page. */

	if (trap_bol_stack.is_empty())
	  curenv->output_pending_lines();
	break;
      }
    default:
      {
	bol = 0;
	tok.process();
	break;
      }
    }
    if (!suppress_next)
      tok.next();
    trap_sprung_flag = 0;
  }
}

#ifdef WIDOW_CONTROL

void flush_pending_lines()
{
  while (!tok.newline() && !tok.eof())
    tok.next();
  curenv->output_pending_lines();
  tok.next();
}

#endif /* WIDOW_CONTROL */

request_or_macro::request_or_macro()
{
}

macro *request_or_macro::to_macro()
{
  return 0;
}

request::request(REQUEST_FUNCP pp) : p(pp)
{
}

void request::invoke(symbol)
{
  (*p)();
}

struct char_block {
  enum { SIZE = 128 };
  unsigned char s[SIZE];
  char_block *next;
  char_block();
};

char_block::char_block()
: next(0)
{
}

class char_list {
public:
  char_list();
  ~char_list();
  void append(unsigned char);
  int length();
private:
  unsigned char *ptr;
  int len;
  char_block *head;
  char_block *tail;
  friend class macro_header;
  friend class string_iterator;
};

char_list::char_list()
: head(0), tail(0), ptr(0), len(0)
{
}

char_list::~char_list()
{
  while (head != 0) {
    char_block *tem = head;
    head = head->next;
    delete tem;
  }
}

int char_list::length()
{
  return len;
}

void char_list::append(unsigned char c)
{
  if (tail == 0) {
    head = tail = new char_block;
    ptr = tail->s;
  }
  else {
    if (ptr >= tail->s + char_block::SIZE) {
      tail->next = new char_block;
      tail = tail->next;
      ptr = tail->s;
    }
  }
  *ptr++ = c;
  len++;
}

class node_list {
  node *head;
  node *tail;
public:
  node_list();
  ~node_list();
  void append(node *);
  int length();
  node *extract();

  friend class macro_header;
  friend class string_iterator;
};

void node_list::append(node *n)
{
  if (head == 0) {
    n->next = 0;
    head = tail = n;
  }
  else {
    n->next = 0;
    tail = tail->next = n;
  }
}

int node_list::length()
{
  int total = 0;
  for (node *n = head; n != 0; n = n->next)
    ++total;
  return total;
}

node_list::node_list()
{
  head = tail = 0;
}

node *node_list::extract()
{
  node *temp = head;
  head = tail = 0;
  return temp;
}


node_list::~node_list()
{
  delete_node_list(head);
}

struct macro_header {
  int count;
  char_list cl;
  node_list nl;
  macro_header() { count = 1; }
  macro_header *copy(int);
};


macro::~macro() 
{ 
  if (p != 0 && --(p->count) <= 0) 
    delete p;
}

macro::macro()
{
  if (!input_stack::get_location(1, &filename, &lineno)) {
    filename = 0;
    lineno = 0;
  }
  length = 0;
  p = 0;
}

macro::macro(const macro &m) 
: filename(m.filename), lineno(m.lineno), p(m.p), length(m.length)
{ 
  if (p != 0)
    p->count++;
}

macro &macro::operator=(const macro &m)
{
  // don't assign object
  if (m.p != 0)
    m.p->count++;
  if (p != 0 && --(p->count) <= 0) 
    delete p; 
  p = m.p; 
  filename = m.filename;
  lineno = m.lineno;
  length = m.length;
  return *this;
}

void macro::append(unsigned char c)
{
  assert(c != 0);
  if (p == 0)
    p = new macro_header;
  if (p->cl.length() != length) {
    macro_header *tem = p->copy(length);
    if (--(p->count) <= 0)
      delete p;
    p = tem;
  }
  p->cl.append(c);
  ++length;
}

void macro::append(node *n)
{
  assert(n != 0);
  if (p == 0)
    p = new macro_header;
  if (p->cl.length() != length) {
    macro_header *tem = p->copy(length);
    if (--(p->count) <= 0)
      delete p;
    p = tem;
  }
  p->cl.append(0);
  p->nl.append(n);
  ++length;
}

void macro::print_size()
{
  errprint("%1", length);
}

// make a copy of the first n bytes

macro_header *macro_header::copy(int n)
{
  macro_header *p = new macro_header;
  char_block *bp = cl.head;
  unsigned char *ptr = bp->s;
  node *nd = nl.head;
  while (--n >= 0) {
    if (ptr >= bp->s + char_block::SIZE) {
      bp = bp->next;
      ptr = bp->s;
    }
    int c = *ptr++;
    p->cl.append(c);
    if (c == 0) {
      p->nl.append(nd->copy());
      nd = nd->next;
    }
  }
  return p;
}

void print_macros()
{
  object_dictionary_iterator iter(request_dictionary);
  request_or_macro *rm;
  symbol s;
  while (iter.get(&s, (object **)&rm)) {
    assert(!s.is_null());
    macro *m = rm->to_macro();
    if (m) {
      errprint("%1\t", s.contents());
      m->print_size();
      errprint("\n");
    }
  }
  fflush(stderr);
  skip_line();
}

class string_iterator : public input_iterator {
  macro mac;
  const char *how_invoked;
  int newline_flag;
  int lineno;
  char_block *bp;
  int count;			// of characters remaining
  node *nd;
protected:
  symbol nm;
  string_iterator();
public:
  string_iterator(const macro &m, const char *p = 0, symbol s = NULL_SYMBOL);
  int fill(node **);
  int peek();
  int get_location(int, const char **, int *);
  void backtrace();
};

string_iterator::string_iterator(const macro &m, const char *p, symbol s) 
: lineno(1), mac(m), newline_flag(0), how_invoked(p), nm(s)
{
  count = mac.length;
  if (count != 0) {
    bp = mac.p->cl.head;
    nd = mac.p->nl.head;
    ptr = eptr = bp->s;
  }
  else {
    bp = 0;
    nd = 0;
    ptr = eptr = 0;
  }
}

string_iterator::string_iterator()
{
  bp = 0;
  nd = 0;
  ptr = eptr = 0;
  newline_flag = 0;
  how_invoked = 0;
  lineno = 1;
  count = 0;
}

int string_iterator::fill(node **np)
{
  if (newline_flag)
    lineno++;
  newline_flag = 0;
  if (count <= 0)
    return EOF;
  const unsigned char *p = eptr;
  if (p >= bp->s + char_block::SIZE) {
    bp = bp->next;
    p = bp->s;
  }
  if (*p == '\0') {
    if (np)
      *np = nd->copy();
    nd = nd->next;
    eptr = ptr = p + 1;
    count--;
    return 0;
  }
  const unsigned char *e = bp->s + char_block::SIZE;
  if (e - p > count)
    e = p + count;
  ptr = p;
  while (p < e) {
    unsigned char c = *p;
    if (c == '\n' || c == ESCAPE_NEWLINE) {
      newline_flag = 1;
      p++;
      break;
    }
    if (c == '\0')
      break;
    p++;
  }
  eptr = p;
  count -= p - ptr;
  return *ptr++;
}

int string_iterator::peek()
{
  if (count <= 0)
    return EOF;
  const unsigned char *p = eptr;
  if (count <= 0)
    return EOF;
  if (p >= bp->s + char_block::SIZE) {
    p = bp->next->s;
  }
  return *p;
}

int string_iterator::get_location(int allow_macro,
				  const char **filep, int *linep)
{
  if (!allow_macro)
    return 0;
  if (mac.filename == 0)
    return 0;
  *filep = mac.filename;
  *linep = mac.lineno + lineno - 1;
  return 1;
}

void string_iterator::backtrace()
{
  if (mac.filename) {
    errprint("%1:%2: backtrace", mac.filename, mac.lineno + lineno - 1);
    if (how_invoked) {
      if (!nm.is_null())
	errprint(": %1 `%2'\n", how_invoked, nm.contents());
      else
	errprint(": %1\n", how_invoked);
    }
    else
      errprint("\n");
  }
}

class temp_iterator : public input_iterator {
  unsigned char *base;
  temp_iterator(const char *, int len);
public:
  ~temp_iterator();
  friend input_iterator *make_temp_iterator(const char *);
};

#ifdef __GNUG__
inline
#endif
temp_iterator::temp_iterator(const char *s, int len)
{
  base = new unsigned char[len];
  memcpy(base, s, len);
  ptr = base;
  eptr = base + len;
}

temp_iterator::~temp_iterator()
{
  a_delete base;
}

class small_temp_iterator : public input_iterator {
private:
  small_temp_iterator(const char *, int);
  ~small_temp_iterator();
  enum { BLOCK = 16 };
  static small_temp_iterator *free_list;
  void *operator new(size_t);
  void operator delete(void *);
  enum { SIZE = 12 };
  unsigned char buf[SIZE];
  friend input_iterator *make_temp_iterator(const char *);
};

small_temp_iterator *small_temp_iterator::free_list = 0;

void *small_temp_iterator::operator new(size_t n)
{
  assert(n == sizeof(small_temp_iterator));
  if (!free_list) {
    free_list = (small_temp_iterator *)new char[sizeof(small_temp_iterator)*BLOCK];
    for (int i = 0; i < BLOCK - 1; i++)
      free_list[i].next = free_list + i + 1;
    free_list[BLOCK-1].next = 0;
  }
  small_temp_iterator *p = free_list;
  free_list = (small_temp_iterator *)(free_list->next);
  p->next = 0;
  return p;
}

#ifdef __GNUG__
inline
#endif
void small_temp_iterator::operator delete(void *p)
{
  if (p) {
    ((small_temp_iterator *)p)->next = free_list;
    free_list = (small_temp_iterator *)p;
  }
}

small_temp_iterator::~small_temp_iterator()
{
}


#ifdef __GNUG__
inline
#endif
small_temp_iterator::small_temp_iterator(const char *s, int len)
{
  for (int i = 0; i < len; i++)
    buf[i] = s[i];
  ptr = buf;
  eptr = buf + len;
}

input_iterator *make_temp_iterator(const char *s)
{