printer: improve object formatting.

There is an issue with the printer in that it produces
output whereby objects continue on the same line after
a multi-line object, e.g:

   (foo (foobly bar
         xyzzy quux) (oops same
                      line))

rather than:

   (foo (foobly bar
         xyzzy quux)
        (oops same line))

There is a simple fix for this: set a flag to force
a line break on the next width-check operation whenever
an object has been broken into multiple lines.

width-check can return a Boolean indication whether
it generated a line break, and so aggregate object
printing routines can tell whether their object
has been broken into lines, and set the flag.

* stream.h (struct strm_base): New member, force_break.
(force_break): Declared.

* stream.c (strm_base_init): Extent initializer to cover
force_break flag.
(put_string, put_char): Clear the force_break flag whenever
we hit column zero.
(width_check): If indent mode is on, and force_break is
true, generate a break. Clear force_break.
(force_break): New function.
(stream_init): Register force-break intrinsic.

* buf.c (buf_print): Set the force break flag if the buffer
was broken into multiple lines.

* hash.c (hash_print_op): Set the force break flag if the
hash was broken into multiple lines.

* lib.c (obj_print_impl): Same logic for lists.

* struct.c (struct_inst_print): Same logic for structs.

* tests/009/json.expected, tests/011/macros-2.expected,
tests/012/struct.tl, tests/017/glob-zarray.expected:
Update expected textual output to reflect new formatting.

10 files changed, 62 insertions, 17 deletions

diff --git a/buf.c b/buf.c
index 3e1ed76a..efd2e4a6 100644
--- a/buf.c
+++ b/buf.c
@@ -622,6 +622,7 @@ val buf_print(val buf, val stream_in)
   val save_mode = test_set_indent_mode(stream, num_fast(indent_off),
                                        num_fast(indent_data));
   val save_indent;
+  int fb = 0;
 
   put_string(lit("#b'"), stream);
 
@@ -630,12 +631,16 @@ val buf_print(val buf, val stream_in)
   while (len-- > 0) {
     format(stream, lit("~,02x"), num_fast(*data++), nao);
     if ((++count & 7) == 0 && len)
-      width_check(stream, chr(' '));
+      if (width_check(stream, chr(' ')))
+        fb = 1;
   }
 
   set_indent(stream, save_indent);
   set_indent_mode(stream, save_mode);
 
+  if (fb)
+    force_break(stream);
+
   return put_char(chr('\''), stream);
 }
 
diff --git a/hash.c b/hash.c
index cc4c36ca..cc1b161f 100644
--- a/hash.c
+++ b/hash.c
@@ -408,7 +408,7 @@ static cnum hash_hash_op(val obj, int *count)
 static void hash_print_op(val hash, val out, val pretty, struct strm_ctx *ctx)
 {
   struct hash *h = coerce(struct hash *, hash->co.handle);
-  int need_space = 0;
+  int need_space = 0, force_br = 0;
   val save_mode = test_set_indent_mode(out, num_fast(indent_off),
                                        num_fast(indent_data));
   val save_indent;
@@ -461,7 +461,8 @@ static void hash_print_op(val hash, val out, val pretty, struct strm_ctx *ctx)
     while ((cell = hash_next(iter))) {
       val key = car(cell);
       val value = cdr(cell);
-      width_check(out, chr(' '));
+      if (width_check(out, chr(' ')))
+        force_br = 1;
 
       put_string(lit("("), out);
       obj_print_impl(key, out, pretty, ctx);
@@ -476,6 +477,9 @@ static void hash_print_op(val hash, val out, val pretty, struct strm_ctx *ctx)
   }
   put_string(lit(")"), out);
 
+  if (force_br)
+    force_break(out);
+
   set_indent_mode(out, save_mode);
   set_indent(out, save_indent);
 }
diff --git a/lib.c b/lib.c
index cf800c52..f2a62d11 100644
--- a/lib.c
+++ b/lib.c
@@ -11109,6 +11109,7 @@ val obj_print_impl(val obj, val out, val pretty, struct strm_ctx *ctx)
         val iter;
         val closepar = chr(')');
         val indent = zero;
+        int force_br = 0;
 
         if (sym == dwim_s && consp(cdr(obj))) {
           put_char(chr('['), out);
@@ -11181,7 +11182,8 @@ finish:
             iter = nil;
             goto dot;
           } else if (consp(d)) {
-            width_check(out, chr(' '));
+            if (width_check(out, chr(' ')))
+              force_br = 1;
           } else {
 dot:
             put_string(lit(" . "), out);
@@ -11189,6 +11191,9 @@ dot:
             put_char(closepar, out);
           }
         }
+
+        if (force_br)
+          force_break(out);
       }
 
       if (save_indent)
@@ -11299,6 +11304,7 @@ dot:
       val save_mode = test_set_indent_mode(out, num_fast(indent_off),
                                            num_fast(indent_data));
       val save_indent;
+      int force_br = 0;
 
       put_string(lit("#("), out);
 
@@ -11308,11 +11314,15 @@ dot:
         val elem = obj->v.vec[i];
         obj_print_impl(elem, out, pretty, ctx);
         if (i < length - 1)
-          width_check(out, chr(' '));
+          if (width_check(out, chr(' ')))
+            force_br = 1;
       }
 
       put_char(chr(')'), out);
 
+      if (force_br)
+        force_break(out);
+
       set_indent(out, save_indent);
       set_indent_mode(out, save_mode);
     }
diff --git a/stream.c b/stream.c
index 56563c0c..3887e77f 100644
--- a/stream.c
+++ b/stream.c
@@ -103,7 +103,7 @@ val shell, shell_arg;
 
 void strm_base_init(struct strm_base *s)
 {
-  static struct strm_base init = { indent_off, 60, 10, 0, 0, 0 };
+  static struct strm_base init = { indent_off, 60, 10, 0, 0, 0, 0 };
   *s = init;
 }
 
@@ -3512,6 +3512,7 @@ val put_string(val string, val stream_in)
       switch (*p) {
       case '\n':
         col = 0;
+        s->force_break = 0;
         break;
       case '\t':
         col = (col + 1) | 7;
@@ -3540,6 +3541,7 @@ val put_char(val ch, val stream_in)
   case L'\n':
     ops->put_char(stream, ch);
     s->column = 0;
+    s->force_break = 0;
     break;
   case L'\t':
     if (s->column == 0 && s->indent_mode != indent_off) {
@@ -3697,14 +3699,25 @@ val width_check(val stream, val alt)
   if ((s->indent_mode == indent_code &&
        s->column >= s->indent_chars + s->code_width) ||
       (s->indent_mode == indent_data &&
-       s->column >= s->indent_chars + s->data_width))
+       s->column >= s->indent_chars + s->data_width) ||
+      (s->indent_mode != indent_off && s->force_break))
   {
     put_char(chr('\n'), stream);
+    s->force_break = 0;
+    return t;
   } else if (alt) {
     put_char(alt, stream);
   }
 
-  return t;
+  return nil;
+}
+
+val force_break(val stream)
+{
+  struct strm_base *s = coerce(struct strm_base *,
+                               cobj_handle(stream, stream_s));
+  s->force_break = 1;
+  return stream;
 }
 
 struct strm_ctx *get_set_ctx(val stream, struct strm_ctx *ctx)
@@ -4596,6 +4609,7 @@ void stream_init(void)
   reg_fun(intern(lit("set-indent"), user_package), func_n2(set_indent));
   reg_fun(intern(lit("inc-indent"), user_package), func_n2(inc_indent));
   reg_fun(intern(lit("width-check"), user_package), func_n2(width_check));
+  reg_fun(intern(lit("force-break"), user_package), func_n1(force_break));
   reg_varl(intern(lit("indent-off"), user_package), num_fast(indent_off));
   reg_varl(intern(lit("indent-data"), user_package), num_fast(indent_data));
   reg_varl(intern(lit("indent-code"), user_package), num_fast(indent_code));
diff --git a/stream.h b/stream.h
index bb581371..12750639 100644
--- a/stream.h
+++ b/stream.h
@@ -49,6 +49,7 @@ struct strm_base {
   cnum code_width;
   cnum indent_chars;
   cnum column;
+  unsigned force_break;
   struct strm_ctx *ctx;
 };
 
@@ -209,6 +210,7 @@ val get_indent(val stream);
 val set_indent(val stream, val indent);
 val inc_indent(val stream, val delta);
 val width_check(val stream, val alt);
+val force_break(val stream);
 struct strm_ctx *get_set_ctx(val stream, struct strm_ctx *);
 struct strm_ctx *get_ctx(val stream);
 val get_string(val stream, val nchars, val close_after_p);
diff --git a/struct.c b/struct.c
index 5f614af2..943cc393 100644
--- a/struct.c
+++ b/struct.c
@@ -1410,6 +1410,7 @@ static void struct_inst_print(val obj, val out, val pretty,
   val save_mode = test_set_indent_mode(out, num_fast(indent_off),
                                        num_fast(indent_data));
   val save_indent, iter, once;
+  int force_br = 0;
   int compat = opt_compat && opt_compat <= 154;
 
   if (!compat || pretty) {
@@ -1433,7 +1434,8 @@ static void struct_inst_print(val obj, val out, val pretty,
         put_char(chr(' '), out);
         once = nil;
       } else {
-        width_check(out, chr(' '));
+        if (width_check(out, chr(' ')))
+          force_br = 1;
       }
       obj_print_impl(sym, out, pretty, ctx);
       put_char(chr(' '), out);
@@ -1441,6 +1443,8 @@ static void struct_inst_print(val obj, val out, val pretty,
     }
   }
   put_char(chr(')'), out);
+  if (force_br)
+    force_break(out);
   set_indent_mode(out, save_mode);
   set_indent(out, save_indent);
 }
diff --git a/tests/009/json.expected b/tests/009/json.expected
index 8bc4ab9a..8c3fc4c6 100644
--- a/tests/009/json.expected
+++ b/tests/009/json.expected
@@ -19,8 +19,9 @@ AST: #H(() ("web-app" #H(() ("servlet-mapping" #H(() ("cofaxTools" "/tools/*") (
                                                                                                           ("dataStoreUrl" "jdbc:microsoft:sqlserver://LOCALHOST:1433;DatabaseName=goon")
                                                                                                           ("useDataStore" :true) ("cachePackageTagsTrack" 200.0) ("searchEngineFileTemplate" "forSearchEngines.htm")
                                                                                                           ("cachePackageTagsStore" 200.0) ("cachePagesRefresh" 10.0)))
-                                         ("servlet-name" "cofaxCDS")) #H(() ("servlet-class" "org.cofax.cds.EmailServlet") ("init-param" #H(() ("mailHost" "mail1") ("mailHostOverride" "mail2")))
-                                                                         ("servlet-name" "cofaxEmail"))
+                                         ("servlet-name" "cofaxCDS"))
+                                      #H(() ("servlet-class" "org.cofax.cds.EmailServlet") ("init-param" #H(() ("mailHost" "mail1") ("mailHostOverride" "mail2")))
+                                         ("servlet-name" "cofaxEmail"))
                                       #H(() ("servlet-class" "org.cofax.cds.AdminServlet") ("servlet-name" "cofaxAdmin"))
                                       #H(() ("servlet-class" "org.cofax.cds.FileServlet") ("servlet-name" "fileServlet"))
                                       #H(() ("servlet-class" "org.cofax.cms.CofaxToolsServlet") ("init-param" #H(() ("lookInContext" 1.0) ("removePageCache" "/content/admin/remove?cache=pages&id=")
@@ -29,7 +30,8 @@ AST: #H(() ("web-app" #H(() ("servlet-mapping" #H(() ("cofaxTools" "/tools/*") (
                                                                                                                  ("log" 1.0) ("adminGroupID" 4.0) ("templatePath" "toolstemplates/")
                                                                                                                  ("betaServer" :true) ("dataLogLocation" "/usr/local/tomcat/logs/dataLog.log")
                                                                                                                  ("fileTransferFolder" "/usr/local/tomcat/webapps/content/fileTransferFolder")))
-                                         ("servlet-name" "cofaxTools")))) ("taglib" #H(() ("taglib-uri" "cofax.tld") ("taglib-location" "/WEB-INF/tlds/cofax.tld"))))))
+                                         ("servlet-name" "cofaxTools"))))
+                         ("taglib" #H(() ("taglib-uri" "cofax.tld") ("taglib-location" "/WEB-INF/tlds/cofax.tld"))))))
 
 Unmatched junk: ""
 
diff --git a/tests/011/macros-2.expected b/tests/011/macros-2.expected
index 7dad1247..0e4cb622 100644
--- a/tests/011/macros-2.expected
+++ b/tests/011/macros-2.expected
@@ -14,8 +14,9 @@
                       ((< i 100) ())
                       () (block #:cnt-blk-0001
                            (if (< (sys:setq i (succ i))
-                                  20) (return-from
-                                        #:cnt-blk-0001))
+                                  20)
+                             (return-from
+                               #:cnt-blk-0001))
                            (if (> i 30)
                              (return-from
                                #:brk-blk-0002))
diff --git a/tests/012/struct.tl b/tests/012/struct.tl
index 7b0b7fd8..99b2a3eb 100644
--- a/tests/012/struct.tl
+++ b/tests/012/struct.tl
@@ -50,11 +50,13 @@
 (set *gensym-counter* 0)
 (stest (ignwarn (sys:expand 's.(a).d))
        "(slot (call (slot s 'a)\n               \
-       \            s) 'd)")
+       \            s)\n                        \
+       \      'd)")
 (set *gensym-counter* 0)
 (stest (ignwarn (sys:expand 's.(a b c).d))
        "(slot (call (slot s 'a)\n               \
-       \            s b c)\n      'd)")
+       \            s b c)\n                    \
+       \      'd)")
 
 (test s.a 100)
 
diff --git a/tests/017/glob-zarray.expected b/tests/017/glob-zarray.expected
index 4bfc0810..cd54b421 100644
--- a/tests/017/glob-zarray.expected
+++ b/tests/017/glob-zarray.expected
@@ -1,3 +1,4 @@
 0
 #S(glob-t pathc 4 pathv #("tests/001/query-1.txr" "tests/001/query-2.txr" "tests/001/query-3.txr"
-                          "tests/001/query-4.txr") reserve 0)
+                          "tests/001/query-4.txr")
+          reserve 0)