aboutsummaryrefslogtreecommitdiff
path: root/contrib/groff/troff/div.cc
diff options
context:
space:
mode:
Diffstat (limited to 'contrib/groff/troff/div.cc')
-rw-r--r--contrib/groff/troff/div.cc1128
1 files changed, 1128 insertions, 0 deletions
diff --git a/contrib/groff/troff/div.cc b/contrib/groff/troff/div.cc
new file mode 100644
index 000000000000..e5b4b589fbd8
--- /dev/null
+++ b/contrib/groff/troff/div.cc
@@ -0,0 +1,1128 @@
+// -*- C++ -*-
+/* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
+ Written by James Clark (jjc@jclark.com)
+
+This file is part of groff.
+
+groff is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+groff is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License along
+with groff; see the file COPYING. If not, write to the Free Software
+Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+
+// diversions
+
+#include "troff.h"
+#include "symbol.h"
+#include "dictionary.h"
+#include "hvunits.h"
+#include "env.h"
+#include "request.h"
+#include "node.h"
+#include "token.h"
+#include "div.h"
+#include "reg.h"
+
+int exit_started = 0; // the exit process has started
+int done_end_macro = 0; // the end macro (if any) has finished
+int seen_last_page_ejector = 0; // seen the LAST_PAGE_EJECTOR cookie
+int last_page_number = 0; // if > 0, the number of the last page
+ // specified with -o
+static int began_page_in_end_macro = 0; // a new page was begun during the end macro
+
+static int last_post_line_extra_space = 0; // needed for \n(.a
+static int nl_reg_contents = -1;
+static int dl_reg_contents = 0;
+static int dn_reg_contents = 0;
+static int vertical_position_traps_flag = 1;
+static vunits truncated_space;
+static vunits needed_space;
+
+diversion::diversion(symbol s)
+: nm(s), prev(0), vertical_position(V0), marked_place(V0), high_water_mark(V0)
+{
+}
+
+struct vertical_size {
+ vunits pre_extra, post_extra, pre, post;
+ vertical_size(vunits vs, vunits post_vs);
+};
+
+vertical_size::vertical_size(vunits vs, vunits post_vs)
+: pre_extra(V0), post_extra(V0), pre(vs), post(post_vs)
+{
+}
+
+void node::set_vertical_size(vertical_size *)
+{
+}
+
+void extra_size_node::set_vertical_size(vertical_size *v)
+{
+ if (n < V0) {
+ if (-n > v->pre_extra)
+ v->pre_extra = -n;
+ }
+ else if (n > v->post_extra)
+ v->post_extra = n;
+}
+
+void vertical_size_node::set_vertical_size(vertical_size *v)
+{
+ if (n < V0)
+ v->pre = -n;
+ else
+ v->post = n;
+}
+
+top_level_diversion *topdiv;
+
+diversion *curdiv;
+
+void do_divert(int append)
+{
+ tok.skip();
+ symbol nm = get_name();
+ if (nm.is_null()) {
+ if (curdiv->prev) {
+ diversion *temp = curdiv;
+ curdiv = curdiv->prev;
+ delete temp;
+ }
+ else
+ warning(WARN_DI, "diversion stack underflow");
+ }
+ else {
+ macro_diversion *md = new macro_diversion(nm, append);
+ md->prev = curdiv;
+ curdiv = md;
+ }
+ skip_line();
+}
+
+void divert()
+{
+ do_divert(0);
+}
+
+void divert_append()
+{
+ do_divert(1);
+}
+
+void diversion::need(vunits n)
+{
+ vunits d = distance_to_next_trap();
+ if (d < n) {
+ space(d, 1);
+ truncated_space = -d;
+ needed_space = n;
+ }
+}
+
+macro_diversion::macro_diversion(symbol s, int append)
+: diversion(s), max_width(H0)
+{
+#if 0
+ if (append) {
+ /* We don't allow recursive appends eg:
+
+ .da a
+ .a
+ .di
+
+ This causes an infinite loop in troff anyway.
+ This is because the user could do
+
+ .as a foo
+
+ in the diversion, and this would mess things up royally,
+ since there would be two things appending to the same
+ macro_header.
+ To make it work, we would have to copy the _contents_
+ of the macro into which we were diverting; this doesn't
+ strike me as worthwhile.
+ However,
+
+ .di a
+ .a
+ .a
+ .di
+
+ will work and will make `a' contain two copies of what it contained
+ before; in troff, `a' would contain nothing. */
+ request_or_macro *rm
+ = (request_or_macro *)request_dictionary.remove(s);
+ if (!rm || (mac = rm->to_macro()) == 0)
+ mac = new macro;
+ }
+ else
+ mac = new macro;
+#endif
+ // We can now catch the situation described above by comparing
+ // the length of the charlist in the macro_header with the length
+ // stored in the macro. When we detect this, we copy the contents.
+ mac = new macro;
+ if (append) {
+ request_or_macro *rm
+ = (request_or_macro *)request_dictionary.lookup(s);
+ if (rm) {
+ macro *m = rm->to_macro();
+ if (m)
+ *mac = *m;
+ }
+ }
+}
+
+macro_diversion::~macro_diversion()
+{
+ request_or_macro *rm = (request_or_macro *)request_dictionary.lookup(nm);
+ macro *m = rm ? rm->to_macro() : 0;
+ if (m) {
+ *m = *mac;
+ delete mac;
+ }
+ else
+ request_dictionary.define(nm, mac);
+ mac = 0;
+ dl_reg_contents = max_width.to_units();
+ dn_reg_contents = vertical_position.to_units();
+}
+
+vunits macro_diversion::distance_to_next_trap()
+{
+ if (!diversion_trap.is_null() && diversion_trap_pos > vertical_position)
+ return diversion_trap_pos - vertical_position;
+ else
+ // Substract vresolution so that vunits::vunits does not overflow.
+ return vunits(INT_MAX - vresolution);
+}
+
+void macro_diversion::transparent_output(unsigned char c)
+{
+ mac->append(c);
+}
+
+void macro_diversion::transparent_output(node *n)
+{
+ mac->append(n);
+}
+
+void macro_diversion::output(node *nd, int retain_size,
+ vunits vs, vunits post_vs, hunits width)
+{
+ vertical_size v(vs, post_vs);
+ while (nd != 0) {
+ nd->set_vertical_size(&v);
+ node *temp = nd;
+ nd = nd->next;
+ if (temp->interpret(mac)) {
+ delete temp;
+ }
+ else {
+#if 1
+ temp->freeze_space();
+#endif
+ mac->append(temp);
+ }
+ }
+ if (!v.post_extra.is_zero())
+ last_post_line_extra_space = v.post_extra.to_units();
+ if (!retain_size) {
+ v.pre = vs;
+ v.post = post_vs;
+ }
+ if (width > max_width)
+ max_width = width;
+ vunits x = v.pre + v.pre_extra + v.post + v.post_extra;
+ if (vertical_position_traps_flag
+ && !diversion_trap.is_null() && diversion_trap_pos > vertical_position
+ && diversion_trap_pos <= vertical_position + x) {
+ vunits trunc = vertical_position + x - diversion_trap_pos;
+ if (trunc > v.post)
+ trunc = v.post;
+ v.post -= trunc;
+ x -= trunc;
+ truncated_space = trunc;
+ spring_trap(diversion_trap);
+ }
+ mac->append(new vertical_size_node(-v.pre));
+ mac->append(new vertical_size_node(v.post));
+ mac->append('\n');
+ vertical_position += x;
+ if (vertical_position - v.post > high_water_mark)
+ high_water_mark = vertical_position - v.post;
+}
+
+void macro_diversion::space(vunits n, int)
+{
+ if (vertical_position_traps_flag
+ && !diversion_trap.is_null() && diversion_trap_pos > vertical_position
+ && diversion_trap_pos <= vertical_position + n) {
+ truncated_space = vertical_position + n - diversion_trap_pos;
+ n = diversion_trap_pos - vertical_position;
+ spring_trap(diversion_trap);
+ }
+ else if (n + vertical_position < V0)
+ n = -vertical_position;
+ mac->append(new diverted_space_node(n));
+ vertical_position += n;
+}
+
+void macro_diversion::copy_file(const char *filename)
+{
+ mac->append(new diverted_copy_file_node(filename));
+}
+
+top_level_diversion::top_level_diversion()
+: page_count(0), have_next_page_number(0), page_length(units_per_inch*11),
+ page_offset(units_per_inch), prev_page_offset(units_per_inch),
+ ejecting_page(0), page_trap_list(0), before_first_page(1), no_space_mode(0),
+ page_number(0), last_page_count(-1)
+{
+}
+
+// find the next trap after pos
+
+trap *top_level_diversion::find_next_trap(vunits *next_trap_pos)
+{
+ trap *next_trap = 0;
+ for (trap *pt = page_trap_list; pt != 0; pt = pt->next)
+ if (!pt->nm.is_null()) {
+ if (pt->position >= V0) {
+ if (pt->position > vertical_position
+ && pt->position < page_length
+ && (next_trap == 0 || pt->position < *next_trap_pos)) {
+ next_trap = pt;
+ *next_trap_pos = pt->position;
+ }
+ }
+ else {
+ vunits pos = pt->position;
+ pos += page_length;
+ if (pos > 0 && pos > vertical_position && (next_trap == 0 || pos < *next_trap_pos)) {
+ next_trap = pt;
+ *next_trap_pos = pos;
+ }
+ }
+ }
+ return next_trap;
+}
+
+vunits top_level_diversion::distance_to_next_trap()
+{
+ vunits d;
+ if (!find_next_trap(&d))
+ return page_length - vertical_position;
+ else
+ return d - vertical_position;
+}
+
+void top_level_diversion::output(node *nd, int retain_size,
+ vunits vs, vunits post_vs, hunits /*width*/)
+{
+ no_space_mode = 0;
+ vunits next_trap_pos;
+ trap *next_trap = find_next_trap(&next_trap_pos);
+ if (before_first_page && begin_page())
+ fatal("sorry, I didn't manage to begin the first page in time: use an explicit .br request");
+ vertical_size v(vs, post_vs);
+ for (node *tem = nd; tem != 0; tem = tem->next)
+ tem->set_vertical_size(&v);
+ if (!v.post_extra.is_zero())
+ last_post_line_extra_space = v.post_extra.to_units();
+ if (!retain_size) {
+ v.pre = vs;
+ v.post = post_vs;
+ }
+ vertical_position += v.pre;
+ vertical_position += v.pre_extra;
+ the_output->print_line(page_offset, vertical_position, nd,
+ v.pre + v.pre_extra, v.post_extra);
+ vertical_position += v.post_extra;
+ if (vertical_position > high_water_mark)
+ high_water_mark = vertical_position;
+ if (vertical_position_traps_flag && vertical_position >= page_length)
+ begin_page();
+ else if (vertical_position_traps_flag
+ && next_trap != 0 && vertical_position >= next_trap_pos) {
+ nl_reg_contents = vertical_position.to_units();
+ truncated_space = v.post;
+ spring_trap(next_trap->nm);
+ }
+ else if (v.post > V0) {
+ vertical_position += v.post;
+ if (vertical_position_traps_flag
+ && next_trap != 0 && vertical_position >= next_trap_pos) {
+ truncated_space = vertical_position - next_trap_pos;
+ vertical_position = next_trap_pos;
+ nl_reg_contents = vertical_position.to_units();
+ spring_trap(next_trap->nm);
+ }
+ else if (vertical_position_traps_flag && vertical_position >= page_length)
+ begin_page();
+ else
+ nl_reg_contents = vertical_position.to_units();
+ }
+ else
+ nl_reg_contents = vertical_position.to_units();
+}
+
+void top_level_diversion::transparent_output(unsigned char c)
+{
+ if (before_first_page && begin_page())
+ // This can only happen with the transparent() request.
+ fatal("sorry, I didn't manage to begin the first page in time: use an explicit .br request");
+ const char *s = asciify(c);
+ while (*s)
+ the_output->transparent_char(*s++);
+}
+
+void top_level_diversion::transparent_output(node * /*n*/)
+{
+ error("can't transparently output node at top level");
+}
+
+void top_level_diversion::copy_file(const char *filename)
+{
+ if (before_first_page && begin_page())
+ fatal("sorry, I didn't manage to begin the first page in time: use an explicit .br request");
+ the_output->copy_file(page_offset, vertical_position, filename);
+}
+
+void top_level_diversion::space(vunits n, int forced)
+{
+ if (no_space_mode) {
+ if (!forced)
+ return;
+ else
+ no_space_mode = 0;
+ }
+ if (before_first_page) {
+ if (begin_page()) {
+ // This happens if there's a top of page trap, and the first-page
+ // transition is caused by `'sp'.
+ truncated_space = n > V0 ? n : V0;
+ return;
+ }
+ }
+ vunits next_trap_pos;
+ trap *next_trap = find_next_trap(&next_trap_pos);
+ vunits y = vertical_position + n;
+ if (vertical_position_traps_flag && next_trap != 0 && y >= next_trap_pos) {
+ vertical_position = next_trap_pos;
+ nl_reg_contents = vertical_position.to_units();
+ truncated_space = y - vertical_position;
+ spring_trap(next_trap->nm);
+ }
+ else if (y < V0) {
+ vertical_position = V0;
+ nl_reg_contents = vertical_position.to_units();
+ }
+ else if (vertical_position_traps_flag && y >= page_length && n >= V0)
+ begin_page();
+ else {
+ vertical_position = y;
+ nl_reg_contents = vertical_position.to_units();
+ }
+}
+
+trap::trap(symbol s, vunits n, trap *p)
+ : nm(s), next(p), position(n)
+{
+}
+
+void top_level_diversion::add_trap(symbol nm, vunits pos)
+{
+ trap *first_free_slot = 0;
+ trap **p;
+ for (p = &page_trap_list; *p; p = &(*p)->next) {
+ if ((*p)->nm.is_null()) {
+ if (first_free_slot == 0)
+ first_free_slot = *p;
+ }
+ else if ((*p)->position == pos) {
+ (*p)->nm = nm;
+ return;
+ }
+ }
+ if (first_free_slot) {
+ first_free_slot->nm = nm;
+ first_free_slot->position = pos;
+ }
+ else
+ *p = new trap(nm, pos, 0);
+}
+
+void top_level_diversion::remove_trap(symbol nm)
+{
+ for (trap *p = page_trap_list; p; p = p->next)
+ if (p->nm == nm) {
+ p->nm = NULL_SYMBOL;
+ return;
+ }
+}
+
+void top_level_diversion::remove_trap_at(vunits pos)
+{
+ for (trap *p = page_trap_list; p; p = p->next)
+ if (p->position == pos) {
+ p->nm = NULL_SYMBOL;
+ return;
+ }
+}
+
+void top_level_diversion::change_trap(symbol nm, vunits pos)
+{
+ for (trap *p = page_trap_list; p; p = p->next)
+ if (p->nm == nm) {
+ p->position = pos;
+ return;
+ }
+}
+
+void top_level_diversion::print_traps()
+{
+ for (trap *p = page_trap_list; p; p = p->next)
+ if (p->nm.is_null())
+ fprintf(stderr, " empty\n");
+ else
+ fprintf(stderr, "%s\t%d\n", p->nm.contents(), p->position.to_units());
+ fflush(stderr);
+}
+
+void end_diversions()
+{
+ while (curdiv != topdiv) {
+ error("automatically ending diversion `%1' on exit",
+ curdiv->nm.contents());
+ diversion *tem = curdiv;
+ curdiv = curdiv->prev;
+ delete tem;
+ }
+}
+
+void cleanup_and_exit(int exit_code)
+{
+ if (the_output) {
+ the_output->trailer(topdiv->get_page_length());
+ delete the_output;
+ }
+ exit(exit_code);
+}
+
+// returns non-zero if it sprung a top of page trap
+
+int top_level_diversion::begin_page()
+{
+ if (exit_started) {
+ if (page_count == last_page_count
+ ? curenv->is_empty()
+ : (done_end_macro && (seen_last_page_ejector || began_page_in_end_macro)))
+ cleanup_and_exit(0);
+ if (!done_end_macro)
+ began_page_in_end_macro = 1;
+ }
+ if (last_page_number > 0 && page_number == last_page_number)
+ cleanup_and_exit(0);
+ if (!the_output)
+ init_output();
+ ++page_count;
+ if (have_next_page_number) {
+ page_number = next_page_number;
+ have_next_page_number = 0;
+ }
+ else if (before_first_page == 1)
+ page_number = 1;
+ else
+ page_number++;
+ // spring the top of page trap if there is one
+ vunits next_trap_pos;
+ vertical_position = -vresolution;
+ trap *next_trap = find_next_trap(&next_trap_pos);
+ vertical_position = V0;
+ high_water_mark = V0;
+ ejecting_page = 0;
+ // If before_first_page was 2, then the top of page transition was undone
+ // using eg .nr nl 0-1. See nl_reg::set_value.
+ if (before_first_page != 2)
+ the_output->begin_page(page_number, page_length);
+ before_first_page = 0;
+ nl_reg_contents = vertical_position.to_units();
+ if (vertical_position_traps_flag && next_trap != 0 && next_trap_pos == V0) {
+ truncated_space = V0;
+ spring_trap(next_trap->nm);
+ return 1;
+ }
+ else
+ return 0;
+}
+
+void continue_page_eject()
+{
+ if (topdiv->get_ejecting()) {
+ if (curdiv != topdiv)
+ error("can't continue page ejection because of current diversion");
+ else if (!vertical_position_traps_flag)
+ error("can't continue page ejection because vertical position traps disabled");
+ else {
+ push_page_ejector();
+ topdiv->space(topdiv->get_page_length(), 1);
+ }
+ }
+}
+
+void top_level_diversion::set_next_page_number(int n)
+{
+ next_page_number= n;
+ have_next_page_number = 1;
+}
+
+int top_level_diversion::get_next_page_number()
+{
+ return have_next_page_number ? next_page_number : page_number + 1;
+}
+
+void top_level_diversion::set_page_length(vunits n)
+{
+ page_length = n;
+}
+
+diversion::~diversion()
+{
+}
+
+void page_offset()
+{
+ hunits n;
+ // The troff manual says that the default scaling indicator is v,
+ // but it is in fact m: v wouldn't make sense for a horizontally
+ // oriented request.
+ if (!has_arg() || !get_hunits(&n, 'm', topdiv->page_offset))
+ n = topdiv->prev_page_offset;
+ topdiv->prev_page_offset = topdiv->page_offset;
+ topdiv->page_offset = n;
+ skip_line();
+}
+
+void page_length()
+{
+ vunits n;
+ if (has_arg() && get_vunits(&n, 'v', topdiv->get_page_length()))
+ topdiv->set_page_length(n);
+ else
+ topdiv->set_page_length(11*units_per_inch);
+ skip_line();
+}
+
+void when_request()
+{
+ vunits n;
+ if (get_vunits(&n, 'v')) {
+ symbol s = get_name();
+ if (s.is_null())
+ topdiv->remove_trap_at(n);
+ else
+ topdiv->add_trap(s, n);
+ }
+ skip_line();
+}
+
+void begin_page()
+{
+ int got_arg = 0;
+ int n;
+ if (has_arg() && get_integer(&n, topdiv->get_page_number()))
+ got_arg = 1;
+ while (!tok.newline() && !tok.eof())
+ tok.next();
+ if (curdiv == topdiv) {
+ if (topdiv->before_first_page) {
+ if (!break_flag) {
+ if (got_arg)
+ topdiv->set_next_page_number(n);
+ if (got_arg || !topdiv->no_space_mode)
+ topdiv->begin_page();
+ }
+ else if (topdiv->no_space_mode && !got_arg)
+ topdiv->begin_page();
+ else {
+ /* Given this
+
+ .wh 0 x
+ .de x
+ .tm \\n%
+ ..
+ .bp 3
+
+ troff prints
+
+ 1
+ 3
+
+ This code makes groff do the same. */
+
+ push_page_ejector();
+ topdiv->begin_page();
+ if (got_arg)
+ topdiv->set_next_page_number(n);
+ topdiv->set_ejecting();
+ }
+ }
+ else {
+ push_page_ejector();
+ if (break_flag)
+ curenv->do_break();
+ if (got_arg)
+ topdiv->set_next_page_number(n);
+ if (!(topdiv->no_space_mode && !got_arg))
+ topdiv->set_ejecting();
+ }
+ }
+ tok.next();
+}
+
+void no_space()
+{
+ if (curdiv == topdiv)
+ topdiv->no_space_mode = 1;
+ skip_line();
+}
+
+void restore_spacing()
+{
+ if (curdiv == topdiv)
+ topdiv->no_space_mode = 0;
+ skip_line();
+}
+
+/* It is necessary to generate a break before before reading the argument,
+because otherwise arguments using | will be wrong. But if we just
+generate a break as usual, then the line forced out may spring a trap
+and thus push a macro onto the input stack before we have had a chance
+to read the argument to the sp request. We resolve this dilemma by
+setting, before generating the break, a flag which will postpone the
+actual pushing of the macro associated with the trap sprung by the
+outputting of the line forced out by the break till after we have read
+the argument to the request. If the break did cause a trap to be
+sprung, then we don't actually do the space. */
+
+void space_request()
+{
+ postpone_traps();
+ if (break_flag)
+ curenv->do_break();
+ vunits n;
+ if (!has_arg() || !get_vunits(&n, 'v'))
+ n = curenv->get_vertical_spacing();
+ while (!tok.newline() && !tok.eof())
+ tok.next();
+ if (!unpostpone_traps())
+ curdiv->space(n);
+ else
+ // The line might have had line spacing that was truncated.
+ truncated_space += n;
+ tok.next();
+}
+
+void blank_line()
+{
+ curenv->do_break();
+ if (!trap_sprung_flag)
+ curdiv->space(curenv->get_vertical_spacing());
+ else
+ truncated_space += curenv->get_vertical_spacing();
+}
+
+/* need_space might spring a trap and so we must be careful that the
+BEGIN_TRAP token is not skipped over. */
+
+void need_space()
+{
+ vunits n;
+ if (!has_arg() || !get_vunits(&n, 'v'))
+ n = curenv->get_vertical_spacing();
+ while (!tok.newline() && !tok.eof())
+ tok.next();
+ curdiv->need(n);
+ tok.next();
+}
+
+void page_number()
+{
+ int n;
+ if (has_arg() && get_integer(&n, topdiv->get_page_number()))
+ topdiv->set_next_page_number(n);
+ skip_line();
+}
+
+vunits saved_space;
+
+void save_vertical_space()
+{
+ vunits x;
+ if (get_vunits(&x, 'v')) {
+ if (curdiv->distance_to_next_trap() > x)
+ curdiv->space(x, 1);
+ else
+ saved_space = x;
+ }
+ skip_line();
+}
+
+void output_saved_vertical_space()
+{
+ while (!tok.newline() && !tok.eof())
+ tok.next();
+ if (saved_space > V0)
+ curdiv->space(saved_space, 1);
+ saved_space = V0;
+ tok.next();
+}
+
+void flush_output()
+{
+ while (!tok.newline() && !tok.eof())
+ tok.next();
+ if (break_flag)
+ curenv->do_break();
+ if (the_output)
+ the_output->flush();
+ tok.next();
+}
+
+void macro_diversion::set_diversion_trap(symbol s, vunits n)
+{
+ diversion_trap = s;
+ diversion_trap_pos = n;
+}
+
+void macro_diversion::clear_diversion_trap()
+{
+ diversion_trap = NULL_SYMBOL;
+}
+
+void top_level_diversion::set_diversion_trap(symbol, vunits)
+{
+ error("can't set diversion trap when no current diversion");
+}
+
+void top_level_diversion::clear_diversion_trap()
+{
+ error("can't set diversion trap when no current diversion");
+}
+
+void diversion_trap()
+{
+ vunits n;
+ if (has_arg() && get_vunits(&n, 'v')) {
+ symbol s = get_name();
+ if (!s.is_null())
+ curdiv->set_diversion_trap(s, n);
+ else
+ curdiv->clear_diversion_trap();
+ }
+ else
+ curdiv->clear_diversion_trap();
+ skip_line();
+}
+
+void change_trap()
+{
+ symbol s = get_name(1);
+ if (!s.is_null()) {
+ vunits x;
+ if (has_arg() && get_vunits(&x, 'v'))
+ topdiv->change_trap(s, x);
+ else
+ topdiv->remove_trap(s);
+ }
+ skip_line();
+}
+
+void print_traps()
+{
+ topdiv->print_traps();
+ skip_line();
+}
+
+void mark()
+{
+ symbol s = get_name();
+ if (s.is_null())
+ curdiv->marked_place = curdiv->get_vertical_position();
+ else if (curdiv == topdiv)
+ set_number_reg(s, nl_reg_contents);
+ else
+ set_number_reg(s, curdiv->get_vertical_position().to_units());
+ skip_line();
+}
+
+// This is truly bizarre. It is documented in the SQ manual.
+
+void return_request()
+{
+ vunits dist = curdiv->marked_place - curdiv->get_vertical_position();
+ if (has_arg()) {
+ if (tok.ch() == '-') {
+ tok.next();
+ vunits x;
+ if (get_vunits(&x, 'v'))
+ dist = -x;
+ }
+ else {
+ vunits x;
+ if (get_vunits(&x, 'v'))
+ dist = x >= V0 ? x - curdiv->get_vertical_position() : V0;
+ }
+ }
+ if (dist < V0)
+ curdiv->space(dist);
+ skip_line();
+}
+
+void vertical_position_traps()
+{
+ int n;
+ if (has_arg() && get_integer(&n))
+ vertical_position_traps_flag = (n != 0);
+ else
+ vertical_position_traps_flag = 1;
+ skip_line();
+}
+
+class page_offset_reg : public reg {
+public:
+ int get_value(units *);
+ const char *get_string();
+};
+
+int page_offset_reg::get_value(units *res)
+{
+ *res = topdiv->get_page_offset().to_units();
+ return 1;
+}
+
+const char *page_offset_reg::get_string()
+{
+ return itoa(topdiv->get_page_offset().to_units());
+}
+
+class page_length_reg : public reg {
+public:
+ int get_value(units *);
+ const char *get_string();
+};
+
+int page_length_reg::get_value(units *res)
+{
+ *res = topdiv->get_page_length().to_units();
+ return 1;
+}
+
+const char *page_length_reg::get_string()
+{
+ return itoa(topdiv->get_page_length().to_units());
+}
+
+class vertical_position_reg : public reg {
+public:
+ int get_value(units *);
+ const char *get_string();
+};
+
+int vertical_position_reg::get_value(units *res)
+{
+ if (curdiv == topdiv && topdiv->before_first_page)
+ *res = -1;
+ else
+ *res = curdiv->get_vertical_position().to_units();
+ return 1;
+}
+
+const char *vertical_position_reg::get_string()
+{
+ if (curdiv == topdiv && topdiv->before_first_page)
+ return "-1";
+ else
+ return itoa(curdiv->get_vertical_position().to_units());
+}
+
+class high_water_mark_reg : public reg {
+public:
+ int get_value(units *);
+ const char *get_string();
+};
+
+int high_water_mark_reg::get_value(units *res)
+{
+ *res = curdiv->get_high_water_mark().to_units();
+ return 1;
+}
+
+const char *high_water_mark_reg::get_string()
+{
+ return itoa(curdiv->get_high_water_mark().to_units());
+}
+
+class distance_to_next_trap_reg : public reg {
+public:
+ int get_value(units *);
+ const char *get_string();
+};
+
+int distance_to_next_trap_reg::get_value(units *res)
+{
+ *res = curdiv->distance_to_next_trap().to_units();
+ return 1;
+}
+
+const char *distance_to_next_trap_reg::get_string()
+{
+ return itoa(curdiv->distance_to_next_trap().to_units());
+}
+
+class diversion_name_reg : public reg {
+public:
+ const char *get_string();
+};
+
+const char *diversion_name_reg::get_string()
+{
+ return curdiv->get_diversion_name();
+}
+
+class page_number_reg : public general_reg {
+public:
+ page_number_reg();
+ int get_value(units *);
+ void set_value(units);
+};
+
+page_number_reg::page_number_reg()
+{
+}
+
+void page_number_reg::set_value(units n)
+{
+ topdiv->set_page_number(n);
+}
+
+int page_number_reg::get_value(units *res)
+{
+ *res = topdiv->get_page_number();
+ return 1;
+}
+
+class next_page_number_reg : public reg {
+public:
+ const char *get_string();
+};
+
+const char *next_page_number_reg::get_string()
+{
+ return itoa(topdiv->get_next_page_number());
+}
+
+class page_ejecting_reg : public reg {
+public:
+ const char *get_string();
+};
+
+const char *page_ejecting_reg::get_string()
+{
+ return itoa(topdiv->get_ejecting());
+}
+
+class constant_vunits_reg : public reg {
+ vunits *p;
+public:
+ constant_vunits_reg(vunits *);
+ const char *get_string();
+};
+
+constant_vunits_reg::constant_vunits_reg(vunits *q) : p(q)
+{
+}
+
+const char *constant_vunits_reg::get_string()
+{
+ return itoa(p->to_units());
+}
+
+class nl_reg : public variable_reg {
+public:
+ nl_reg();
+ void set_value(units);
+};
+
+nl_reg::nl_reg() : variable_reg(&nl_reg_contents)
+{
+}
+
+void nl_reg::set_value(units n)
+{
+ variable_reg::set_value(n);
+ // Setting nl to a negative value when the vertical position in
+ // the top-level diversion is 0 undoes the top of page transition,
+ // so that the header macro will be called as if the top of page
+ // transition hasn't happened. This is used by Larry Wall's
+ // wrapman program. Setting before_first_page to 2 rather than 1,
+ // tells top_level_diversion::begin_page not to call
+ // output_file::begin_page again.
+ if (n < 0 && topdiv->get_vertical_position() == V0)
+ topdiv->before_first_page = 2;
+}
+
+void init_div_requests()
+{
+ init_request("wh", when_request);
+ init_request("ch", change_trap);
+ init_request("pl", page_length);
+ init_request("po", page_offset);
+ init_request("rs", restore_spacing);
+ init_request("ns", no_space);
+ init_request("sp", space_request);
+ init_request("di", divert);
+ init_request("da", divert_append);
+ init_request("bp", begin_page);
+ init_request("ne", need_space);
+ init_request("pn", page_number);
+ init_request("dt", diversion_trap);
+ init_request("rt", return_request);
+ init_request("mk", mark);
+ init_request("sv", save_vertical_space);
+ init_request("os", output_saved_vertical_space);
+ init_request("fl", flush_output);
+ init_request("vpt", vertical_position_traps);
+ init_request("ptr", print_traps);
+ number_reg_dictionary.define(".a",
+ new constant_int_reg(&last_post_line_extra_space));
+ number_reg_dictionary.define(".z", new diversion_name_reg);
+ number_reg_dictionary.define(".o", new page_offset_reg);
+ number_reg_dictionary.define(".p", new page_length_reg);
+ number_reg_dictionary.define(".d", new vertical_position_reg);
+ number_reg_dictionary.define(".h", new high_water_mark_reg);
+ number_reg_dictionary.define(".t", new distance_to_next_trap_reg);
+ number_reg_dictionary.define("dl", new variable_reg(&dl_reg_contents));
+ number_reg_dictionary.define("dn", new variable_reg(&dn_reg_contents));
+ number_reg_dictionary.define("nl", new nl_reg);
+ number_reg_dictionary.define(".vpt",
+ new constant_int_reg(&vertical_position_traps_flag));
+ number_reg_dictionary.define("%", new page_number_reg);
+ number_reg_dictionary.define(".pn", new next_page_number_reg);
+ number_reg_dictionary.define(".trunc",
+ new constant_vunits_reg(&truncated_space));
+ number_reg_dictionary.define(".ne",
+ new constant_vunits_reg(&needed_space));
+ number_reg_dictionary.define(".pe", new page_ejecting_reg);
+}