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authorLuigi Scarso <luigi.scarso@gmail.com>2018-09-05 21:57:30 +0000
committerLuigi Scarso <luigi.scarso@gmail.com>2018-09-05 21:57:30 +0000
commitecd1605a23ef54d2a4a69e1a361172d350e03b3b (patch)
tree8ea1d9745c24dbc5e755f13d801fa01e88944650 /Build/source/texk/web2c/luatexdir/tex/align.c
parent04563248956e7059aad4fc4f6bf7da18562f7b8c (diff)
luatex: correct automake file for pplib; replaced cweb files with c files.
git-svn-id: svn://tug.org/texlive/trunk@48594 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Build/source/texk/web2c/luatexdir/tex/align.c')
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diff --git a/Build/source/texk/web2c/luatexdir/tex/align.c b/Build/source/texk/web2c/luatexdir/tex/align.c
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+++ b/Build/source/texk/web2c/luatexdir/tex/align.c
@@ -0,0 +1,1297 @@
+/*
+
+Copyright 2009-2010 Taco Hoekwater <taco@luatex.org>
+
+This file is part of LuaTeX.
+
+LuaTeX 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 of the License, or (at your
+option) any later version.
+
+LuaTeX 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 Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU General Public License along
+with LuaTeX; if not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+#include "ptexlib.h"
+
+void fin_align(void);
+void init_row(void);
+void init_col(void);
+
+#define noDEBUG
+
+/*tex
+
+ It's sort of a miracle whenever \.{\\halign} and \.{\\valign} work, because
+ they cut across so many of the control structures of \TeX. Therefore the
+ present page is probably not the best place for a beginner to start reading
+ this program; it is better to master everything else first.
+
+ Let us focus our thoughts on an example of what the input might be, in order
+ to get some idea about how the alignment miracle happens. The example doesn't
+ do anything useful, but it is sufficiently general to indicate all of the
+ special cases that must be dealt with; please do not be disturbed by its
+ apparent complexity and meaninglessness.
+
+ \starttyping
+ \tabskip 2pt plus 3pt
+ \halign to 300pt{u1#v1&
+ \hskip 50pt \tabskip 1pt plus 1fil u2#v2&
+ \hskip 50pt u3#v3\cr
+ \hskip 25pt a1&\omit a2&\vrule\cr
+ \hskip 25pt \noalign\{\vskip 3pt}
+ \hskip 25pt b1\span b2\cr
+ \hskip 25pt \omit&c2\span\omit\cr}
+ \stoptyping
+
+ Here's what happens:
+
+ \startitemize
+
+ \startitem
+ When `\.{\\halign to 300pt\{}' is scanned, the |scan_spec| routine
+ places the 300pt dimension onto the |save_stack|, and an
+ |align_group| code is placed above it. This will make it possible to
+ complete the alignment when the matching `\.\}' is found.
+ \stopitem
+
+ \startitem
+ The preamble is scanned next. Macros in the preamble are not
+ expanded, except as part of a tabskip specification. For example, if
+ \.{u2} had been a macro in the preamble above, it would have been
+ expanded, since \TeX\ must look for `\.{minus...}' as part of the
+ tabskip glue. A ``preamble list'' is constructed based on the user's
+ preamble; in our case it contains the following seven items:
+
+ \starttabulate
+ \NC \type{\glue 2pt plus 3pt} \NC the tabskip preceding column 1 \NC \NR
+ \NC \type{\alignrecord} of width $-\infty$ \NC preamble info for column 1 \NC \NR
+ \NC \type{\glue 2pt plus 3pt} \NC the tabskip between columns 1 and 2 \NC \NR
+ \NC \type{\alignrecord} of width $-\infty$ \NC preamble info for column 2 \NC \NR
+ \NC \type{\glue 1pt plus 1fil} \NC the tabskip between columns 2 and 3 \NC \NR
+ \NC \type{\alignrecord} of width $-\infty$ \NC preamble info for column 3 \NC \NR
+ \NC \type{\glue 1pt plus 1fil} \NC the tabskip following column 3 \NC \NR
+ \stoptabulate
+
+ These ``alignrecord'' entries have the same size as an |unset_node|,
+ since they will later be converted into such nodes. These alignrecord
+ nodes have no |depth| field; this is split into |u_part| and
+ |v_part|, and they point to token lists for the templates of the
+ alignment. For example, the |u_part| field in the first alignrecord
+ points to the token list `\.{u1}', i.e., the template preceding the
+ `\.\#' for column~1. Furthermore, They have a |span_ptr| instead of a
+ |node_attr| field, and these |span_ptr| fields are initially set to
+ the value |end_span|, for reasons explained below.
+ \stopitem
+
+ \startitem
+ \TeX\ now looks at what follows the \.{\\cr} that ended the preamble.
+ It is not `\.{\\noalign}' or `\.{\\omit}', so this input is put back
+ to be read again, and the template `\.{u1}' is fed to the scanner.
+ Just before reading `\.{u1}', \TeX\ goes into restricted horizontal
+ mode. Just after reading `\.{u1}', \TeX\ will see `\.{a1}', and then
+ (when the {\.\&} is sensed) \TeX\ will see `\.{v1}'. Then \TeX\ scans
+ an |endv| token, indicating the end of a column. At this point an
+ |unset_node| is created, containing the contents of the current hlist
+ (i.e., `\.{u1a1v1}'). The natural width of this unset node replaces
+ the |width| field of the alignrecord for column~1; in general, the
+ alignrecords will record the maximum natural width that has occurred
+ so far in a given column.
+ \stopitem
+
+ \startitem
+ Since `\.{\\omit}' follows the `\.\&', the templates for column~2 are
+ now bypassed. Again \TeX\ goes into restricted horizontal mode and
+ makes an |unset_node| from the resulting hlist; but this time the
+ hlist contains simply `\.{a2}'. The natural width of the new unset
+ box is remembered in the |width| field of the alignrecord for
+ column~2.
+ \stopitem
+
+ \startitem
+ A third |unset_node| is created for column 3, using essentially the
+ mechanism that worked for column~1; this unset box contains
+ `\.{u3\\vrule v3}'. The vertical rule in this case has running
+ dimensions that will later extend to the height and depth of the
+ whole first row, since each |unset_node| in a row will eventually
+ inherit the height and depth of its enclosing box.
+ \stopitem
+
+ \startitem
+ The first row has now ended; it is made into a single unset box
+ comprising the following seven items:
+
+ \starttyping
+ \glue 2pt plus 3pt
+ \unsetbox for 1 column: u1a1v1
+ \glue 2pt plus 3pt
+ \unsetbox for 1 column: a2
+ \glue 1pt plus 1fil
+ \unsetbox for 1 column: u3\vrule v3
+ \glue 1pt plus 1fil
+ \stoptyping
+
+ The width of this unset row is unimportant, but it has the correct
+ height and depth, so the correct baselineskip glue will be computed
+ as the row is inserted into a vertical list.
+ \stopitem
+
+ \startitem
+ Since `\.{\\noalign}' follows the current \.{\\cr}, \TeX\ appends
+ additional material (in this case \.{\\vskip 3pt}) to the vertical
+ list. While processing this material, \TeX\ will be in internal
+ vertical mode, and |no_align_group| will be on |save_stack|.
+ \stopitem
+
+ \startitem
+ The next row produces an unset box that looks like this:
+
+ \starttyping
+ \glue 2pt plus 3pt
+ \unsetbox for 2 columns: u1b1v1u2b2v2
+ \glue 1pt plus 1fil
+ \unsetbox for 1 column: {(empty)}
+ \glue 1pt plus 1fil
+ \stoptyping
+
+ The natural width of the unset box that spans columns 1~and~2 is
+ stored in a ``span node,'' which we will explain later; the
+ |span_ptr| field of the alignrecord for column~1 now points to the
+ new span node, and the |span_ptr| of the span node points to
+ |end_span|.
+ \stopitem
+
+ \startitem
+
+ The final row produces the unset box
+
+ \starttyping
+ \glue 2pt plus 3pt\cr
+ \unsetbox for 1 column: {(empty)}
+ \glue 2pt plus 3pt\cr
+ \unsetbox for 2 columns: u2c2v2
+ \glue 1pt plus 1fil
+ \stoptyping
+
+ A new span node is attached to the alignrecord for column 2.
+ \stopitem
+
+ \startitem
+ The last step is to compute the true column widths and to change all
+ the unset boxes to hboxes, appending the whole works to the vertical
+ list that encloses the \.{\\halign}. The rules for deciding on the
+ final widths of each unset column box will be explained below.
+ \stopitem
+
+ \stopitemize
+
+ Note that as \.{\\halign} is being processed, we fearlessly give up control
+ to the rest of \TeX. At critical junctures, an alignment routine is called
+ upon to step in and do some little action, but most of the time these
+ routines just lurk in the background. It's something like post-hypnotic
+ suggestion.
+
+ We have mentioned that alignrecords contain no |height| or |depth| fields.
+ Their |glue_sign| and |glue_order| are pre-empted as well, since it is
+ necessary to store information about what to do when a template ends. This
+ information is called the |extra_info| field.
+
+*/
+
+/*tex The pointer to \<u_j> token list: */
+
+#define u_part(A) vlink((A)+depth_offset)
+
+/*tex The pointer to \<v_j> token list */
+
+#define v_part(A) vinfo((A)+depth_offset)
+
+/*tex A column spanning list */
+
+#define span_ptr(A) vinfo((A)+1)
+
+/*tex Info to remember during template */
+
+#define extra_info(A) vinfo((A)+list_offset)
+
+/*tex
+
+ Alignments can occur within alignments, so a small stack is used to access
+ the alignrecord information. At each level we have a |preamble| pointer,
+ indicating the beginning of the preamble list; a |cur_align| pointer,
+ indicating the current position in the preamble list; a |cur_span| pointer,
+ indicating the value of |cur_align| at the beginning of a sequence of spanned
+ columns; a |cur_loop| pointer, indicating the tabskip glue before an
+ alignrecord that should be copied next if the current list is extended; and
+ the |align_state| variable, which indicates the nesting of braces so that
+ \.{\\cr} and \.{\\span} and tab marks are properly intercepted. There also
+ are pointers |cur_head| and |cur_tail| to the head and tail of a list of
+ adjustments being moved out from horizontal mode to vertical~mode, and alike
+ |cur_pre_head| and |cur_pre_tail| for pre-adjust lists.
+
+ The current values of these nine quantities appear in global variables; when
+ they have to be pushed down, they are stored in 6-word nodes, and |align_ptr|
+ points to the topmost such node.
+
+*/
+
+/*tex This could be in |texnodes.h| but it's documented here. */
+
+/*tex The current preamble list: */
+
+#define preamble vlink(align_head)
+
+/*tex The current position in the preamble list: */
+
+pointer cur_align = null;
+
+/*tex The start of the currently spanned columns in the preamble list: */
+
+pointer cur_span = null;
+
+/*tex A place to copy when extending a periodic preamble: */
+
+pointer cur_loop = null;
+
+/*tex The most recently pushed-down alignment stack node: */
+
+pointer align_ptr = null;
+
+/*tex Adjustment list pointers: */
+
+pointer cur_head = null, cur_tail = null;
+
+/*tex Pre-adjustment list pointers: */
+
+pointer cur_pre_head = null, cur_pre_tail = null;
+
+/*tex
+
+ The |align_state| and |preamble| variables are initialized elsewhere.
+
+ Alignment stack maintenance is handled by a pair of trivial routines called
+ |push_alignment| and |pop_alignment|.
+
+ (HH:) It makes not much sense to add support for an \.{attr} keyword to
+ \.{\\halign} and \.{\\valign} because then we need to decide if we tag rows
+ or cells or both or come up with \.{cellattr} and \.{rowattr} and such. But
+ then it even makes sense to have explicit commands (in addition to the
+ seperator) to tags individual cells. Too muss hassle for now and the
+ advantages are not that large.
+
+*/
+
+static void push_alignment(void)
+{
+ /*tex The new alignment stack node: */
+ pointer p;
+ p = new_node(align_stack_node, 0);
+ vinfo(p + 1) = align_ptr;
+ vlink(p + 1) = cur_align;
+ vinfo(p + 2) = preamble;
+ vlink(p + 2) = cur_span;
+ vinfo(p + 3) = cur_loop;
+ vlink(p + 3) = align_state;
+ vinfo(p + 4) = cur_head;
+ vlink(p + 4) = cur_tail;
+ vinfo(p + 5) = cur_pre_head;
+ vlink(p + 5) = cur_pre_tail;
+ align_ptr = p;
+ cur_head = new_node(temp_node, 0);
+ cur_pre_head = new_node(temp_node, 0);
+}
+
+static void pop_alignment(void)
+{
+ /*tex The top alignment stack node: */
+ pointer p;
+ flush_node(cur_head);
+ flush_node(cur_pre_head);
+ p = align_ptr;
+ cur_pre_tail = vlink(p + 5);
+ cur_pre_head = vinfo(p + 5);
+ cur_tail = vlink(p + 4);
+ cur_head = vinfo(p + 4);
+ align_state = vlink(p + 3);
+ cur_loop = vinfo(p + 3);
+ cur_span = vlink(p + 2);
+ preamble = vinfo(p + 2);
+ cur_align = vlink(p + 1);
+ align_ptr = vinfo(p + 1);
+ flush_node(p);
+}
+
+/*tex
+
+ \TeX\ has eight procedures that govern alignments: |init_align| and
+ |fin_align| are used at the very beginning and the very end; |init_row| and
+ |fin_row| are used at the beginning and end of individual rows; |init_span|
+ is used at the beginning of a sequence of spanned columns (possibly involving
+ only one column); |init_col| and |fin_col| are used at the beginning and end
+ of individual columns; and |align_peek| is used after \.{\\cr} to see whether
+ the next item is \.{\\noalign}.
+
+ We shall consider these routines in the order they are first used during the
+ course of a complete \.{\\halign}, namely |init_align|, |align_peek|,
+ |init_row|, |init_span|, |init_col|, |fin_col|, |fin_row|, |fin_align|.
+
+ The preamble is copied directly, except that \.{\\tabskip} causes a change to
+ the tabskip glue, thereby possibly expanding macros that immediately follow
+ it. An appearance of \.{\\span} also causes such an expansion.
+
+ Note that if the preamble contains `\.{\\global\\tabskip}', the
+ `\.{\\global}' token survives in the preamble and the `\.{\\tabskip}' defines
+ new tabskip glue (locally).
+
+*/
+
+static void get_preamble_token(void)
+{
+ RESTART:
+ get_token();
+ while ((cur_chr == span_code) && (cur_cmd == tab_mark_cmd)) {
+ /*tex This token will be expanded once. */
+ get_token();
+ if (cur_cmd > max_command_cmd) {
+ expand();
+ get_token();
+ }
+ }
+ if (cur_cmd == endv_cmd)
+ fatal_error("(interwoven alignment preambles are not allowed)");
+ if ((cur_cmd == assign_glue_cmd)
+ && (cur_chr == glue_base + tab_skip_code)) {
+ scan_optional_equals();
+ scan_glue(glue_val_level);
+ if (global_defs_par > 0)
+ geq_define(glue_base + tab_skip_code, glue_ref_cmd, cur_val);
+ else
+ eq_define(glue_base + tab_skip_code, glue_ref_cmd, cur_val);
+ goto RESTART;
+ }
+}
+
+/*tex
+
+ When \.{\\halign} or \.{\\valign} has been scanned in an appropriate mode,
+ \TeX\ calls |init_align|, whose task is to get everything off to a good
+ start. This mostly involves scanning the preamble and putting its information
+ into the preamble list.
+
+*/
+
+void init_align(void)
+{
+ /*tex |warning_index| value for error messages */
+ pointer save_cs_ptr;
+ /*tex for short-term temporary use */
+ pointer p, r;
+ /*tex \.{\\halign} or \.{\\valign}, usually */
+ save_cs_ptr = cur_cs;
+ push_alignment();
+ /*tex enter a new alignment level */
+ align_state = -1000000;
+ /*tex
+
+ When \.{\\halign} is used as a displayed formula, there should be no
+ other pieces of mlists present.
+
+ */
+ if ((cur_list.mode_field == mmode) && ((cur_list.tail_field != cur_list.head_field) || (incompleat_noad_par != null))) {
+ const char *hlp[] = {
+ "Displays can use special alignments (like \\eqalignno)",
+ "only if nothing but the alignment itself is between $$'s.",
+ "So I've deleted the formulas that preceded this alignment.",
+ NULL
+ };
+ tex_error("Improper \\halign inside $$'s", hlp);
+ flush_math();
+ }
+ /*tex Enter a new semantic level. */
+ push_nest();
+ /*tex
+
+ In vertical modes, |prev_depth| already has the correct value. But if we
+ are in |mmode| (displayed formula mode), we reach out to the enclosing
+ vertical mode for the |prev_depth| value that produces the correct
+ baseline calculations.
+ */
+ if (cur_list.mode_field == mmode) {
+ cur_list.mode_field = -vmode;
+ prev_depth_par = nest[nest_ptr - 2].prev_depth_field;
+ } else if (cur_list.mode_field > 0) {
+ cur_list.mode_field = -(cur_list.mode_field);
+ }
+ scan_spec(align_group);
+ /*tex Scan the preamble. */
+ preamble = null;
+ cur_align = align_head;
+ cur_loop = null;
+ scanner_status = aligning;
+ warning_index = save_cs_ptr;
+ align_state = -1000000;
+ /*tex At this point, |cur_cmd=left_brace|. */
+ while (true) {
+ /*tex Append the current tabskip glue to the preamble list. */
+ r = new_param_glue(tab_skip_code);
+ vlink(cur_align) = r;
+ cur_align = vlink(cur_align);
+ if (cur_cmd == car_ret_cmd) {
+ /*tex \.{\\cr} ends the preamble. */
+ break;
+ }
+ /*tex
+
+ Scan preamble text until |cur_cmd| is |tab_mark| or |car_ret| and
+ then scan the template \<u_j>, putting the resulting token list in
+ |hold_token_head|. Spaces are eliminated from the beginning of a
+ template.
+
+ */
+ p = hold_token_head;
+ token_link(p) = null;
+ while (1) {
+ get_preamble_token();
+ if (cur_cmd == mac_param_cmd)
+ break;
+ if ((cur_cmd <= car_ret_cmd) && (cur_cmd >= tab_mark_cmd)
+ && (align_state == -1000000)) {
+ if ((p == hold_token_head) && (cur_loop == null) && (cur_cmd == tab_mark_cmd)) {
+ cur_loop = cur_align;
+ } else {
+ const char *hlp[] = {
+ "There should be exactly one # between &'s, when an",
+ "\\halign or \\valign is being set up. In this case you had",
+ "none, so I've put one in; maybe that will work.",
+ NULL
+ };
+ back_input();
+ tex_error("Missing # inserted in alignment preamble", hlp);
+ break;
+ }
+ } else if ((cur_cmd != spacer_cmd) || (p != hold_token_head)) {
+ r = get_avail();
+ token_link(p) = r;
+ p = token_link(p);
+ token_info(p) = cur_tok;
+ }
+ }
+ r = new_node(align_record_node, 0);
+ vlink(cur_align) = r;
+ /*tex A new align record: */
+ cur_align = vlink(cur_align);
+ span_ptr(cur_align) = end_span;
+ width(cur_align) = null_flag;
+ u_part(cur_align) = token_link(hold_token_head);
+ /*tex
+
+ Scan the template \<v_j>, putting the resulting token list in
+ |hold_token_head|.
+
+ */
+ p = hold_token_head;
+ token_link(p) = null;
+ while (1) {
+ CONTINUE:
+ get_preamble_token();
+ if ((cur_cmd <= car_ret_cmd) && (cur_cmd >= tab_mark_cmd) && (align_state == -1000000))
+ break;
+ if (cur_cmd == mac_param_cmd) {
+ const char *hlp[] = {
+ "There should be exactly one # between &'s, when an",
+ "\\halign or \\valign is being set up. In this case you had",
+ "more than one, so I'm ignoring all but the first.",
+ NULL
+ };
+ tex_error("Only one # is allowed per tab", hlp);
+ goto CONTINUE;
+ }
+ r = get_avail();
+ token_link(p) = r;
+ p = token_link(p);
+ token_info(p) = cur_tok;
+ }
+ r = get_avail();
+ token_link(p) = r;
+ p = token_link(p);
+ /*tex Put \.{\\endtemplate} at the end: */
+ token_info(p) = end_template_token;
+ v_part(cur_align) = token_link(hold_token_head);
+ }
+ scanner_status = normal;
+ new_save_level(align_group);
+ if (every_cr_par != null)
+ begin_token_list(every_cr_par, every_cr_text);
+ /*tex Look for \.{\\noalign} or \.{\\omit}. */
+ align_peek();
+}
+
+/*tex
+
+ The tricky part about alignments is getting the templates into the scanner at
+ the right time, and recovering control when a row or column is finished.
+
+ We usually begin a row after each \.{\\cr} has been sensed, unless that
+ \.{\\cr} is followed by \.{\\noalign} or by the right brace that terminates
+ the alignment. The |align_peek| routine is used to look ahead and do the
+ right thing; it either gets a new row started, or gets a \.{\\noalign}
+ started, or finishes off the alignment.
+
+*/
+
+void align_peek(void)
+{
+ RESTART:
+ align_state = 1000000;
+ do {
+ get_x_or_protected();
+ } while (cur_cmd == spacer_cmd);
+ if (cur_cmd == no_align_cmd) {
+ scan_left_brace();
+ new_save_level(no_align_group);
+ if (cur_list.mode_field == -vmode)
+ normal_paragraph();
+ } else if (cur_cmd == right_brace_cmd) {
+ fin_align();
+ } else if ((cur_cmd == car_ret_cmd) && (cur_chr == cr_cr_code)) {
+ /*tex Ignore \.{\\crcr}. */
+ goto RESTART;
+ } else {
+ /*tex Start a new row. */
+ init_row();
+ /*tex Start a new column and replace what we peeked at. */
+ init_col();
+ }
+}
+
+
+/*tex
+
+ The parameter to |init_span| is a pointer to the alignrecord where the next
+ column or group of columns will begin. A new semantic level is entered, so
+ that the columns will generate a list for subsequent packaging.
+
+*/
+
+static void init_span(pointer p)
+{
+ push_nest();
+ if (cur_list.mode_field == -hmode) {
+ space_factor_par = 1000;
+ } else {
+ prev_depth_par = ignore_depth;
+ normal_paragraph();
+ }
+ cur_span = p;
+}
+
+/*tex
+
+ To start a row (i.e., a `row' that rhymes with `dough' but not with `bough'),
+ we enter a new semantic level, copy the first tabskip glue, and change from
+ internal vertical mode to restricted horizontal mode or vice versa. The
+ |space_factor| and |prev_depth| are not used on this semantic level, but we
+ clear them to zero just to be tidy.
+
+*/
+
+void init_row(void)
+{
+ push_nest();
+ cur_list.mode_field = (-hmode - vmode) - cur_list.mode_field;
+ if (cur_list.mode_field == -hmode)
+ space_factor_par = 0;
+ else
+ prev_depth_par = 0;
+ tail_append(new_glue(preamble));
+ subtype(cur_list.tail_field) = tab_skip_code + 1;
+ cur_align = vlink(preamble);
+ cur_tail = cur_head;
+ cur_pre_tail = cur_pre_head;
+ init_span(cur_align);
+}
+
+/*tex
+
+ When a column begins, we assume that |cur_cmd| is either |omit| or else the
+ current token should be put back into the input until the \<u_j> template has
+ been scanned. (Note that |cur_cmd| might be |tab_mark| or |car_ret|.) We also
+ assume that |align_state| is approximately 1000000 at this time. We remain in
+ the same mode, and start the template if it is called for.
+
+*/
+
+void init_col(void)
+{
+ extra_info(cur_align) = cur_cmd;
+ if (cur_cmd == omit_cmd)
+ align_state = 0;
+ else {
+ back_input();
+ begin_token_list(u_part(cur_align), u_template);
+ }
+ /*tex now |align_state=1000000| */
+}
+
+
+/*tex
+
+ The scanner sets |align_state| to zero when the \<u_j> template ends. When a
+ subsequent \.{\\cr} or \.{\\span} or tab mark occurs with |align_state=0|,
+ the scanner activates the following code, which fires up the \<v_j> template.
+ We need to remember the |cur_chr|, which is either |cr_cr_code|, |cr_code|,
+ |span_code|, or a character code, depending on how the column text has ended.
+
+ This part of the program had better not be activated when the preamble to
+ another alignment is being scanned, or when no alignment preamble is active.
+
+*/
+
+void insert_vj_template(void)
+{
+ if ((scanner_status == aligning) || (cur_align == null))
+ fatal_error("(interwoven alignment preambles are not allowed)");
+ cur_cmd = extra_info(cur_align);
+ extra_info(cur_align) = cur_chr;
+ if (cur_cmd == omit_cmd)
+ begin_token_list(omit_template, v_template);
+ else
+ begin_token_list(v_part(cur_align), v_template);
+ align_state = 1000000;
+}
+
+/*tex Determine the stretch order */
+
+#define determine_stretch_order() do { \
+ if (total_stretch[filll]!= 0) o = filll; \
+ else if (total_stretch[fill] != 0) o = fill; \
+ else if (total_stretch[fil] != 0) o = fil; \
+ else if (total_stretch[sfi] != 0) o = sfi; \
+ else o=normal; \
+} while (0)
+
+/*tex Determine the shrink order */
+
+#define determine_shrink_order() do { \
+ if (total_shrink[filll] != 0) o = filll; \
+ else if (total_shrink[fill] != 0) o = fill; \
+ else if (total_shrink[fil] != 0) o = fil; \
+ else if (total_shrink[sfi] != 0) o = sfi; \
+ else o=normal; \
+} while (0)
+
+/*tex
+
+ When the |endv| command at the end of a \<v_j> template comes through the
+ scanner, things really start to happen; and it is the |fin_col| routine that
+ makes them happen. This routine returns |true| if a row as well as a column
+ has been finished.
+
+*/
+
+boolean fin_col(void)
+{
+ /*tex the alignrecord after the current one */
+ pointer p;
+ /*tex temporary pointers for list manipulation */
+ pointer q, r;
+ /*tex a new span node */
+ pointer s;
+ /*tex a new unset box */
+ pointer u;
+ /*tex natural width */
+ scaled w;
+ /*tex order of infinity */
+ unsigned char o;
+ /*tex span counter */
+ halfword n;
+ if (cur_align == null)
+ confusion("endv");
+ q = vlink(cur_align);
+ if (q == null)
+ confusion("endv");
+ if (align_state < 500000)
+ fatal_error("(interwoven alignment preambles are not allowed)");
+ p = vlink(q);
+ /*tex If the preamble list has been traversed, check that the row has ended. */
+ if ((p == null) && (extra_info(cur_align) < cr_code)) {
+ if (cur_loop != null) {
+ /*tex Lengthen the preamble periodically: */
+ r = new_node(align_record_node, 0);
+ vlink(q) = r;
+ /*tex A new align record: */
+ p = vlink(q);
+ span_ptr(p) = end_span;
+ width(p) = null_flag;
+ cur_loop = vlink(cur_loop);
+ /*tex Copy the templates from node |cur_loop| into node |p|. */
+ q = hold_token_head;
+ r = u_part(cur_loop);
+ while (r != null) {
+ s = get_avail();
+ token_link(q) = s;
+ q = token_link(q);
+ token_info(q) = token_info(r);
+ r = token_link(r);
+ }
+ token_link(q) = null;
+ u_part(p) = token_link(hold_token_head);
+ q = hold_token_head;
+ r = v_part(cur_loop);
+ while (r != null) {
+ s = get_avail();
+ token_link(q) = s;
+ q = token_link(q);
+ token_info(q) = token_info(r);
+ r = token_link(r);
+ }
+ token_link(q) = null;
+ v_part(p) = token_link(hold_token_head);
+ cur_loop = vlink(cur_loop);
+ r = new_glue(cur_loop);
+ vlink(p) = r;
+ } else {
+ const char *hlp[] = {
+ "You have given more \\span or & marks than there were",
+ "in the preamble to the \\halign or \\valign now in progress.",
+ "So I'll assume that you meant to type \\cr instead.",
+ NULL
+ };
+ extra_info(cur_align) = cr_code;
+ tex_error("Extra alignment tab has been changed to \\cr", hlp);
+ }
+ }
+ if (extra_info(cur_align) != span_code) {
+ unsave();
+ new_save_level(align_group);
+ /*tex Package an unset box for the current column and record its width. */
+ if (cur_list.mode_field == -hmode) {
+ adjust_tail = cur_tail;
+ pre_adjust_tail = cur_pre_tail;
+ u = filtered_hpack(cur_list.head_field, cur_list.tail_field, 0, additional, align_set_group, -1, 0, 0);
+ w = width(u);
+ cur_tail = adjust_tail;
+ adjust_tail = null;
+ cur_pre_tail = pre_adjust_tail;
+ pre_adjust_tail = null;
+ } else {
+ u = filtered_vpackage(vlink(cur_list.head_field), 0, additional, 0, align_set_group, -1, 0, 0);
+ w = height(u);
+ }
+ /*tex This represents a span count of 1: */
+ n = min_quarterword;
+ if (cur_span != cur_align) {
+ /*tex Update width entry for spanned columns. */
+ q = cur_span;
+ do {
+ incr(n);
+ q = vlink(vlink(q));
+ } while (q != cur_align);
+ if (n > max_quarterword) {
+ /*tex This can happen, but won't. */
+ confusion("too many spans");
+ }
+ q = cur_span;
+ while (span_span(span_ptr(q)) < n) {
+ q = span_ptr(q);
+ }
+ if (span_span(span_ptr(q)) > n) {
+ s = new_span_node(span_ptr(q), n, w);
+ span_ptr(q) = s;
+ } else if (width(span_ptr(q)) < w) {
+ width(span_ptr(q)) = w;
+ }
+ } else if (w > width(cur_align)) {
+ width(cur_align) = w;
+ }
+ type(u) = unset_node;
+ span_count(u) = (quarterword) n;
+ determine_stretch_order();
+ glue_order(u) = o;
+ glue_stretch(u) = total_stretch[o];
+ determine_shrink_order();
+ glue_sign(u) = o;
+ glue_shrink(u) = total_shrink[o];
+ pop_nest();
+ vlink(cur_list.tail_field) = u;
+ cur_list.tail_field = u;
+ /*tex Copy the tabskip glue between columns. */
+ tail_append(new_glue(vlink(cur_align)));
+ subtype(cur_list.tail_field) = tab_skip_code + 1;
+ if (extra_info(cur_align) >= cr_code) {
+ return true;
+ }
+ init_span(p);
+ }
+ align_state = 1000000;
+ do {
+ get_x_or_protected();
+ } while (cur_cmd == spacer_cmd);
+ cur_align = p;
+ init_col();
+ return false;
+}
+
+/*tex
+
+ A span node is a 3-word record containing |width|, |span_span|, and
+ |span_ptr| fields. The |span_span| field indicates the number of spanned
+ columns; the |span_ptr| field points to a span node for the same starting
+ column, having a greater extent of spanning, or to |end_span|, which has the
+ largest possible |span_span| field; the |width| field holds the largest
+ natural width corresponding to a particular set of spanned columns.
+
+ A list of the maximum widths so far, for spanned columns starting at a given
+ column, begins with the |span_ptr| field of the alignrecord for that column.
+ The code has to make sure that there is room for |span_ptr| in both the
+ alignrecord and the span nodes, which is why |span_ptr| replaces |node_attr|.
+
+ The |new_span_node| function is defined in |texnodes.c|.
+
+*/
+
+/*tex This is normally |alink|: */
+
+#ifndef span_span
+# define span_span(A) vlink((A)+1)
+#endif
+
+/*tex
+
+ At the end of a row, we append an unset box to the current vlist (for
+ \.{\\halign}) or the current hlist (for \.{\\valign}). This unset box
+ contains the unset boxes for the columns, separated by the tabskip glue.
+ Everything will be set later.
+
+*/
+
+void fin_row(void)
+{
+ /*tex The new unset box: */
+ pointer p;
+ if (cur_list.mode_field == -hmode) {
+ p = filtered_hpack(cur_list.head_field, cur_list.tail_field, 0,
+ additional, fin_row_group, -1, 0, 0);
+ pop_nest();
+ if (cur_pre_head != cur_pre_tail)
+ append_list(cur_pre_head, cur_pre_tail);
+ append_to_vlist(p,lua_key_index(alignment));
+ if (cur_head != cur_tail)
+ append_list(cur_head, cur_tail);
+ } else {
+ p = filtered_vpackage(vlink(cur_list.head_field),
+ 0, additional, max_depth_par, fin_row_group, -1, 0, 0);
+ pop_nest();
+ vlink(cur_list.tail_field) = p;
+ cur_list.tail_field = p;
+ space_factor_par = 1000;
+ }
+ type(p) = unset_node;
+ glue_stretch(p) = 0;
+ if (every_cr_par != null)
+ begin_token_list(every_cr_par, every_cr_text);
+ align_peek();
+ /*tex Note that |glue_shrink(p)=0| since |glue_shrink==shift_amount|. */
+}
+
+/*tex
+
+ Finally, we will reach the end of the alignment, and we can breathe a sigh of
+ relief that memory hasn't overflowed. All the unset boxes will now be set so
+ that the columns line up, taking due account of spanned columns.
+
+*/
+
+void fin_align(void)
+{
+ /*tex registers for the list operations */
+ pointer p, q, r, s, u, rr;
+ /*tex width of column */
+ scaled t, w;
+ /*tex shift offset for unset boxes */
+ scaled o;
+ /*tex matching span amount */
+ halfword n;
+ /*tex temporary storage for |overfull_rule| */
+ scaled rule_save;
+ /*tex temporary storage for |prev_depth| */
+ halfword pd;
+ /*tex temporary storage for |new_glue| */
+ halfword ng;
+ /*tex The |align_group| was for individual entries: */
+ if (cur_group != align_group)
+ confusion("align1");
+ unsave();
+ /*tex The |align_group| was for the whole alignment: */
+ if (cur_group != align_group)
+ confusion("align0");
+ unsave();
+ if (nest[nest_ptr - 1].mode_field == mmode) {
+ o = display_indent_par;
+ } else {
+ o = 0;
+ }
+ /*tex
+
+ Go through the preamble list, determining the column widths and
+ changing the alignrecords to dummy unset boxes.
+
+ It's time now to dismantle the preamble list and to compute the
+ column widths. Let $w_{ij}$ be the maximum of the natural widths of
+ all entries that span columns $i$ through $j$, inclusive. The
+ alignrecord for column~$i$ contains $w_{ii}$ in its |width| field,
+ and there is also a linked list of the nonzero $w_{ij}$ for
+ increasing $j$, accessible via the |info| field; these span nodes
+ contain the value $j-i+|min_quarterword|$ in their |link| fields. The
+ values of $w_{ii}$ were initialized to |null_flag|, which we regard
+ as $-\infty$.
+
+ The final column widths are defined by the formula $$w_j=\max_{1\L
+ i\L j}\biggl( w_{ij}-\sum_{i\L k<j}(t_k+w_k)\biggr),$$ where $t_k$ is
+ the natural width of the tabskip glue between columns $k$ and~$k+1$.
+ However, if $w_{ij}=-\infty$ for all |i| in the range |1<=i<=j|
+ (i.e., if every entry that involved column~|j| also involved
+ column~|j+1|), we let $w_j=0$, and we zero out the tabskip glue after
+ column~|j|.
+
+ \TeX\ computes these values by using the following scheme: First
+ $w_1=w_{11}$. Then replace $w_{2j}$ by $\max(w_{2j},w_{1j}-t_1-w_1)$,
+ for all $j>1$. Then $w_2=w_{22}$. Then replace $w_{3j}$ by
+ $\max(w_{3j},w_{2j}-t_2-w_2)$ for all $j>2$; and so on. If any $w_j$
+ turns out to be $-\infty$, its value is changed to zero and so is the
+ next tabskip.
+
+ */
+ q = vlink(preamble);
+ do {
+ flush_list(u_part(q));
+ flush_list(v_part(q));
+ p = vlink(vlink(q));
+ if (width(q) == null_flag) {
+ /*tex Nullify |width(q)| and the tabskip glue following this column. */
+ width(q) = 0;
+ r = vlink(q);
+ reset_glue_to_zero(r);
+ }
+ if (span_ptr(q) != end_span) {
+ /*tex
+
+ Merge the widths in the span nodes of |q| with those of |p|,
+ destroying the span nodes of |q|.
+
+ Merging of two span-node lists is a typical exercise in the
+ manipulation of linearly linked data structures. The essential
+ invariant in the following |repeat| loop is that we want to
+ dispense with node |r|, in |q|'s list, and |u| is its successor;
+ all nodes of |p|'s list up to and including |s| have been
+ processed, and the successor of |s| matches |r| or precedes |r|
+ or follows |r|, according as |link(r)=n| or |link(r)>n| or
+ |link(r)<n|.
+
+ */
+ t = width(q) + width(vlink(q));
+ r = span_ptr(q);
+ s = end_span;
+ span_ptr(s) = p;
+ n = min_quarterword + 1;
+ do {
+ width(r) = width(r) - t;
+ u = span_ptr(r);
+ while (span_span(r) > n) {
+ s = span_ptr(s);
+ n = span_span(span_ptr(s)) + 1;
+ }
+ if (span_span(r) < n) {
+ span_ptr(r) = span_ptr(s);
+ span_ptr(s) = r;
+ decr(span_span(r));
+ s = r;
+ } else {
+ if (width(r) > width(span_ptr(s)))
+ width(span_ptr(s)) = width(r);
+ flush_node(r);
+ }
+ r = u;
+ } while (r != end_span);
+ }
+ type(q) = unset_node;
+ span_count(q) = min_quarterword;
+ height(q) = 0;
+ depth(q) = 0;
+ glue_order(q) = normal;
+ glue_sign(q) = normal;
+ glue_stretch(q) = 0;
+ glue_shrink(q) = 0;
+ q = p;
+ } while (q != null);
+ /*tex
+
+ Package the preamble list, to determine the actual tabskip glue amounts,
+ and let |p| point to this prototype box.
+
+ Now the preamble list has been converted to a list of alternating unset
+ boxes and tabskip glue, where the box widths are equal to the final
+ column sizes. In case of \.{\\valign}, we change the widths to heights,
+ so that a correct error message will be produced if the alignment is
+ overfull or underfull.
+
+ */
+ decr(save_ptr);
+ pack_begin_line = -cur_list.ml_field;
+ if (cur_list.mode_field == -vmode) {
+ rule_save = overfull_rule_par;
+ /*tex Prevent the rule from being packaged. */
+ overfull_rule_par = 0;
+ p = hpack(preamble, saved_value(0), saved_level(0), -1);
+ overfull_rule_par = rule_save;
+ } else {
+ q = vlink(preamble);
+ do {
+ height(q) = width(q);
+ width(q) = 0;
+ q = vlink(vlink(q));
+ } while (q != null);
+ p = filtered_vpackage(preamble,
+ saved_value(0), saved_level(0), max_depth_par, preamble_group, -1, 0, 0);
+ q = vlink(preamble);
+ do {
+ width(q) = height(q);
+ height(q) = 0;
+ q = vlink(vlink(q));
+ } while (q != null);
+ }
+ pack_begin_line = 0;
+ /*tex Set the glue in all the unset boxes of the current list. */
+ q = vlink(cur_list.head_field);
+ s = cur_list.head_field;
+ while (q != null) {
+ if (!is_char_node(q)) {
+ if (type(q) == unset_node) {
+ /*tex
+
+ We set the unset box |q| and the unset boxes in it. The unset
+ box |q| represents a row that contains one or more unset
+ boxes, depending on how soon \.{\\cr} occurred in that row.
+
+ */
+ if (cur_list.mode_field == -vmode) {
+ type(q) = hlist_node;
+ subtype(q) = align_row_list;
+ width(q) = width(p);
+ } else {
+ type(q) = vlist_node;
+ subtype(q) = align_row_list;
+ height(q) = height(p);
+ }
+ glue_order(q) = glue_order(p);
+ glue_sign(q) = glue_sign(p);
+ glue_set(q) = glue_set(p);
+ shift_amount(q) = o;
+ r = vlink(list_ptr(q));
+ assert (type(r) == unset_node);
+ s = vlink(list_ptr(p));
+ do {
+ /*tex
+
+ We set the glue in node |r| and change it from an unset
+ node. A box made from spanned columns will be followed by
+ tabskip glue nodes and by empty boxes as if there were no
+ spanning. This permits perfect alignment of subsequent
+ entries, and it prevents values that depend on floating
+ point arithmetic from entering into the dimensions of any
+ boxes.
+
+ */
+ n = span_count(r);
+ t = width(s);
+ w = t;
+ u = hold_head;
+ while (n > min_quarterword) {
+ decr(n);
+ /*tex
+
+ Append tabskip glue and an empty box to list |u|, and
+ update |s| and |t| as the prototype nodes are passed.
+
+ */
+ s = vlink(s);
+ ng = new_glue(s);
+ vlink(u) = ng;
+ u = vlink(u);
+ subtype(u) = tab_skip_code + 1;
+ t = t + width(s);
+ if (glue_sign(p) == stretching) {
+ if (stretch_order(s) == glue_order(p))
+ t = t + round(float_cast(glue_set(p)) * float_cast(stretch(s)));
+ } else if (glue_sign(p) == shrinking) {
+ if (shrink_order(s) == glue_order(p))
+ t = t - round(float_cast(glue_set(p)) * float_cast(shrink(s)));
+ }
+ s = vlink(s);
+ rr = new_null_box();
+ vlink(u) = rr;
+ u = vlink(u);
+ t = t + width(s);
+ subtype(u) = align_cell_list;
+ if (cur_list.mode_field == -vmode) {
+ width(u) = width(s);
+ } else {
+ type(u) = vlist_node;
+ height(u) = width(s);
+ }
+ }
+ if (cur_list.mode_field == -vmode) {
+ /*tex
+
+ Make the unset node |r| into an |hlist_node| of width
+ |w|, setting the glue as if the width were |t|.
+
+ */
+ height(r) = height(q);
+ depth(r) = depth(q);
+ if (t == width(r)) {
+ glue_sign(r) = normal;
+ glue_order(r) = normal;
+ set_glue_ratio_zero(glue_set(r));
+ } else if (t > width(r)) {
+ glue_sign(r) = stretching;
+ if (glue_stretch(r) == 0)
+ set_glue_ratio_zero(glue_set(r));
+ else
+ glue_set(r) = unfloat((double) (t - width(r)) / glue_stretch(r));
+ } else {
+ glue_order(r) = glue_sign(r);
+ glue_sign(r) = shrinking;
+ if (glue_shrink(r) == 0)
+ set_glue_ratio_zero(glue_set(r));
+ else if ((glue_order(r) == normal) && (width(r) - t > glue_shrink(r)))
+ set_glue_ratio_one(glue_set(r));
+ else
+ glue_set(r) = unfloat((double) (width(r) - t) / glue_shrink(r));
+ }
+ width(r) = w;
+ type(r) = hlist_node;
+ subtype(r) = align_cell_list;
+
+ } else {
+ /*tex
+
+ Make the unset node |r| into a |vlist_node| of height
+ |w|, setting the glue as if the height were |t|.
+
+ */
+ width(r) = width(q);
+ if (t == height(r)) {
+ glue_sign(r) = normal;
+ glue_order(r) = normal;
+ set_glue_ratio_zero(glue_set(r));
+ } else if (t > height(r)) {
+ glue_sign(r) = stretching;
+ if (glue_stretch(r) == 0)
+ set_glue_ratio_zero(glue_set(r));
+ else
+ glue_set(r) = unfloat((t - height(r)) / glue_stretch(r));
+ } else {
+ glue_order(r) = glue_sign(r);
+ glue_sign(r) = shrinking;
+ if (glue_shrink(r) == 0)
+ set_glue_ratio_zero(glue_set(r));
+ else if ((glue_order(r) == normal) && (height(r) - t > glue_shrink(r)))
+ set_glue_ratio_one(glue_set(r));
+ else
+ glue_set(r) = unfloat((height(r) - t) / glue_shrink(r));
+ }
+ height(r) = w;
+ type(r) = vlist_node;
+ subtype(r) = align_cell_list;
+ }
+ shift_amount(r) = 0;
+ if (u != hold_head) {
+ /*tex Append blank boxes to account for spanned nodes. */
+ vlink(u) = vlink(r);
+ vlink(r) = vlink(hold_head);
+ r = u;
+ }
+
+ r = vlink(vlink(r));
+ s = vlink(vlink(s));
+ } while (r != null);
+
+ } else if (type(q) == rule_node) {
+ /*tex
+
+ Make the running dimensions in rule |q| extend to the
+ boundaries of the alignment.
+
+ */
+ if (is_running(width(q)))
+ width(q) = width(p);
+ if (is_running(height(q)))
+ height(q) = height(p);
+ if (is_running(depth(q)))
+ depth(q) = depth(p);
+ if (o != 0) {
+ r = vlink(q);
+ vlink(q) = null;
+ q = hpack(q, 0, additional, -1);
+ shift_amount(q) = o;
+ subtype(q) = align_cell_list;
+ vlink(q) = r;
+ vlink(s) = q;
+ }
+ }
+ }
+ s = q;
+ q = vlink(q);
+ }
+ flush_node_list(p);
+ pop_alignment();
+ /*tex
+
+ We now have a completed alignment, in the list that starts at
+ |cur_list.head_field| and ends at |cur_list.tail_field|. This list will
+ be merged with the one that encloses it. (In case the enclosing mode is
+ |mmode|, for displayed formulas, we will need to insert glue before and
+ after the display; that part of the program will be deferred until we're
+ more familiar with such operations.)
+
+ */
+ pd = prev_depth_par;
+ p = vlink(cur_list.head_field);
+ q = cur_list.tail_field;
+ pop_nest();
+ if (cur_list.mode_field == mmode) {
+ finish_display_alignment(p, q, pd);
+ } else {
+ prev_depth_par = pd;
+ vlink(cur_list.tail_field) = p;
+ if (p != null)
+ cur_list.tail_field = q;
+ if (cur_list.mode_field == vmode) {
+ if (!output_active)
+ lua_node_filter_s(buildpage_filter_callback,lua_key_index(alignment));
+ build_page();
+ }
+ }
+}
+
+/*tex
+
+ The token list |omit_template| just referred to is a constant token list that
+ contains the special control sequence \.{\\endtemplate} only.
+
+*/
+
+void initialize_alignments(void)
+{
+ token_info(omit_template) = end_template_token;
+ span_span(end_span) = max_quarterword + 1;
+ span_ptr(end_span) = null;
+}