pkg adf7b760f2 12/76: More symbol reading

[Gerd Moellmann]

branch: pkg
commit adf7b760f2830f2adb77a28a6e912b7b47efae72
Author: Gerd Möllmann <gerd@gnu.org>
Commit: Gerd Möllmann <gerd@gnu.org>

    More symbol reading
---
 src/lread.c | 59 +++++++++++++++++++++++++++++++++++------------------------
 1 file changed, 35 insertions(+), 24 deletions(-)

diff --git a/src/lread.c b/src/lread.c
index edd50efd16..b812474a2c 100644
--- a/src/lread.c
+++ b/src/lread.c
@@ -4133,18 +4133,7 @@ read0 (Lisp_Object readcharfun, bool locate_syms)
        char *end = read_buffer + read_buffer_size;
        EMACS_INT start_position = readchar_offset - 1;
 
-       /* PKG-FIXME check.  And this code is much too long.  */
-
-       /* If of the form ||, everything except '|' is considered quoted.
-          the bars doesn't belong to the symbol name.  */
-       bool in_vertical_bar = false;
-       if (!read_emacs_syntax && c == '|')
-         {
-           in_vertical_bar = true;
-           c = READCHAR;
-           if (c < 0)
-             end_of_file_error ();
-         }
+       /* PKG-FIXME: This is too complicated.  */
 
        /* Remember where package prefixes end in COLON, which
           will be set to the first colon we find.  NCOLONS is the
@@ -4154,11 +4143,14 @@ read0 (Lisp_Object readcharfun, bool locate_syms)
 
        /* True means last character read was a backslash.  */
        bool last_was_backslash = false;
+       bool in_vertical_bar = false;
        bool any_quoted = false;
 
        for (;;)
          {
-           if (c == ':' && !last_was_backslash && !in_vertical_bar)
+           if (c == ':'
+               // This is actually \: or |...:
+               && !last_was_backslash && !in_vertical_bar)
              {
                /* Remember where the first : is.  */
                if (colon == NULL)
@@ -4167,7 +4159,8 @@ read0 (Lisp_Object readcharfun, bool locate_syms)
 
                if (!read_emacs_syntax)
                  {
-                   /* #:xyz should not contain a colon.  */
+                   /* #:xyz should not contain a colon unless in Emacs
+                      original syntax.  */
                    if (uninterned_symbol)
                      invalid_syntax ("colon in uninterned symbol", 
readcharfun);
 
@@ -4178,18 +4171,36 @@ read0 (Lisp_Object readcharfun, bool locate_syms)
                  }
              }
 
-           /* Handle backslash.  The first backslash is not part of
-              the symbol name.  \\ gives a single \ in the
-              symbol.  */
-           if (c == '\\' && !last_was_backslash)
+           /* Handle unquote backslash and bar .    */
+           if (!last_was_backslash)
              {
-               c = READCHAR;
-               if (c < 0)
-                 end_of_file_error ();
-               last_was_backslash = true;
-               any_quoted = true;
-               continue;
+               /* Unquoted backslash: The first backslash is not part
+                  of the symbol name.  \\ gives a single \ in the
+                  symbol.  */
+               if (c == '\\')
+                 {
+                   c = READCHAR;
+                   if (c < 0)
+                     end_of_file_error ();
+                   last_was_backslash = true;
+                   any_quoted = true;
+                   continue;
+                 }
+
+               /* Unquoted vertical bar.  Begin or end multi-escape,
+                  unless in Emacs syntax.  In either case, proceed
+                  with next char, the bar is not part of the
+                  name.  */
+               if (c == '|' && !read_emacs_syntax)
+                 {
+                   c = READCHAR;
+                   if (c < 0)
+                     end_of_file_error ();
+                   in_vertical_bar = !in_vertical_bar;
+                   continue;
+                 }
              }
+
            last_was_backslash = false;
 
            /* Store the character read, and advance the write pointer