Pic's `with' attribute now accepts positions.

* src/preproc/pic/pic.y: Make `.', BOX, CIRCLE, ELLIPSE, ARC, LINE,
ARROW, SPLINE, and `[' left-associative tokens to fix shift/reduce
conflicts.
(object_spec): Add rule for `WITH' and `position'.
(relative_path): Give `corner' the precedence of `CHOP'.
* src/preproc/pic/object.h (path): New members `pos' and
`is_position'.
* src/preproc/pic/object.cc: Updated initializers of `path'.
(path::follow): Handle `is_position'.

* doc/pic.ms: Completely updated grammar description.
Many typographical improvements.

4 files changed, 54 insertions, 21 deletions

diff --git a/src/preproc/pic/object.cc b/src/preproc/pic/object.cc
index 30d49067..3d32bf53 100644
--- a/src/preproc/pic/object.cc
+++ b/src/preproc/pic/object.cc
@@ -1782,18 +1782,28 @@ string_list::~string_list()
   a_delete str;
 }
   
-/* A path is used to hold the argument to the with attribute. For example,
-`.nw' or `.A.s' or `.A'. The major operation on a path is to take a 
-place and follow the path through the place to place within the place.
-Note that `.A.B.C.sw' will work. */
+/* A path is used to hold the argument to the `with' attribute.  For
+   example, `.nw' or `.A.s' or `.A'.  The major operation on a path is to
+   take a place and follow the path through the place to place within the
+   place.  Note that `.A.B.C.sw' will work.
+
+   For compatibility with DWB pic, `with' accepts positions also (this
+   is incorrectly documented in CSTR 116). */
 
 path::path(corner c)
-: crn(c), label_list(0), ypath(0)
+: crn(c), label_list(0), ypath(0), is_position(0)
 {
 }
 
+path::path(position p)
+: crn(0), label_list(0), ypath(0), is_position(1)
+{
+  pos.x = p.x;
+  pos.y = p.y;
+}
+
 path::path(char *l, corner c)
-: crn(c), ypath(0)
+: crn(c), ypath(0), is_position(0)
 {
   label_list = new string_list(l);
 }
@@ -1831,6 +1841,12 @@ void path::set_ypath(path *p)
 
 int path::follow(const place &pl, place *result) const
 {
+  if (is_position) {
+    result->x = pos.x;
+    result->y = pos.y;
+    result->obj = 0;
+    return 1;
+  }
   const place *p = &pl;
   for (string_list *lb = label_list; lb; lb = lb->next)
     if (p->obj == 0 || (p = p->obj->find_label(lb->str)) == 0) {
@@ -1840,9 +1856,9 @@ int path::follow(const place &pl, place *result) const
   if (crn == 0 || p->obj == 0)
     *result = *p;
   else {
-    position pos = ((p->obj)->*(crn))();
-    result->x = pos.x;
-    result->y = pos.y;
+    position ps = ((p->obj)->*(crn))();
+    result->x = ps.x;
+    result->y = ps.y;
     result->obj = 0;
   }
   if (ypath) {
diff --git a/src/preproc/pic/object.h b/src/preproc/pic/object.h
index dc6cf57f..98937f93 100644
--- a/src/preproc/pic/object.h
+++ b/src/preproc/pic/object.h
@@ -1,5 +1,5 @@
 // -*- C++ -*-
-/* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
+/* Copyright (C) 1989, 1990, 1991, 1992, 2002 Free Software Foundation, Inc.
      Written by James Clark (jjc@jclark.com)
 
 This file is part of groff.
@@ -76,11 +76,14 @@ struct place {
 struct string_list;
 
 class path {
+  position pos;
   corner crn;
   string_list *label_list;
   path *ypath;
+  int is_position;
 public:
   path(corner = 0);
+  path(position);
   path(char *, corner = 0);
   ~path();
   void append(corner);
diff --git a/src/preproc/pic/pic.man b/src/preproc/pic/pic.man
index 2add8cb5..6054f197 100644
--- a/src/preproc/pic/pic.man
+++ b/src/preproc/pic/pic.man
@@ -52,7 +52,7 @@ the original English.
 ]
 [
 .I filename
-\&.\|.\|.
+\&.\|.\|.\&
 ]
 .br
 .B @g@pic
@@ -62,7 +62,7 @@ the original English.
 ]
 [
 .I filename
-\&.\|.\|.
+\&.\|.\|.\&
 ]
 .
 .
diff --git a/src/preproc/pic/pic.y b/src/preproc/pic/pic.y
index b3a35133..4771e763 100644
--- a/src/preproc/pic/pic.y
+++ b/src/preproc/pic/pic.y
@@ -224,6 +224,8 @@ char *do_sprintf(const char *form, const double *v, int nv);
 %token DEFINE
 %token UNDEF
 
+%left '.'
+
 /* this ensures that plot 17 "%g" parses as (plot 17 "%g") */
 %left PLOT
 %left TEXT SPRINTF
@@ -244,6 +246,8 @@ parses properly. */
 %left VARIABLE NUMBER '(' SIN COS ATAN2 LOG EXP SQRT K_MAX K_MIN INT RAND SRAND LAST 
 %left ORDINAL HERE '`'
 
+%left BOX CIRCLE ELLIPSE ARC LINE ARROW SPLINE '['
+
 /* these need to be lower than '-' */
 %left HEIGHT RADIUS WIDTH DIAMETER FROM TO AT THICKNESS
 
@@ -478,7 +482,7 @@ print_args:
 	;
 
 print_arg:
-  	expr               %prec ','
+  	expr							%prec ','
 		{
 		  $$.str = new char[GDIGITS + 1];
 		  sprintf($$.str, "%g", $1);
@@ -487,7 +491,7 @@ print_arg:
 		}
 	| text
 		{ $$ = $1; }
-	| position          %prec ','
+	| position						%prec ','
 		{
 		  $$.str = new char[GDIGITS + 2 + GDIGITS + 1];
 		  sprintf($$.str, "%g, %g", $1.x, $1.y);
@@ -674,7 +678,7 @@ object_spec:
 		  lookup_variable("linewid", & $$->segment_width);
 		  $$->dir = current_direction;
 		}
-	| text   %prec TEXT
+	| text							%prec TEXT
 		{
 		  $$ = new object_spec(TEXT_OBJECT);
 		  $$->text = new text_item($1.str, $1.filename, $1.lineno);
@@ -742,7 +746,7 @@ object_spec:
 		  $$->radius = $3/2.0;
 		  $$->flags |= HAS_RADIUS;
 		}
-	| object_spec expr %prec HEIGHT
+	| object_spec expr					%prec HEIGHT
 		{
 		  $$ = $1;
 		  $$->flags |= HAS_SEGMENT;
@@ -857,6 +861,15 @@ object_spec:
 		  $$->flags |= HAS_WITH;
 		  $$->with = $3;
 		}
+	| object_spec WITH position				%prec ','
+		{
+		  $$ = $1;
+		  $$->flags |= HAS_WITH;
+		  position pos;
+		  pos.x = $3.x;
+		  pos.y = $3.y;
+		  $$->with = new path(pos);
+		}
 	| object_spec BY expr_pair
 		{
 		  $$ = $1;
@@ -1006,7 +1019,7 @@ object_spec:
 		  $$ = $1;
 		  $$->flags &= ~IS_CLOCKWISE;
 		}
-	| object_spec text   %prec TEXT
+	| object_spec text					%prec TEXT
 		{
 		  $$ = $1;
 		  text_item **p;
@@ -1165,7 +1178,8 @@ expr_pair:
 	;
 
 place:
-	label  %prec CHOP /* line at A left == line (at A) left */
+	/* line at A left == line (at A) left */
+	label							%prec CHOP
 		{ $$ = $1; }
 	| label corner
 		{
@@ -1296,11 +1310,11 @@ label_path:
 	;
 
 relative_path:
-	corner
+	corner							%prec CHOP
 		{ $$ = new path($1); }
 	/* give this a lower precedence than LEFT and RIGHT so that
 	   [A: box] with .A left == [A: box] with (.A left) */
-  	| label_path %prec TEXT
+  	| label_path						%prec TEXT
 		{ $$ = $1; }
 	| label_path corner
 		{
@@ -1491,7 +1505,7 @@ expr:
 		    YYABORT;
 		  }
 		}
-	| '-' expr    %prec '!'
+	| '-' expr						%prec '!'
 		{ $$ = -$2; }
 	| '(' any_expr ')'
 		{ $$ = $2; }