Syntax: Introduce &. and friends

Incompatible change.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/README b/README
index 006b57f62eaeacb6cb0927dcfe67b3968121e15b..67ce6cc17c8fd3755ecddf39a675a073850f11ff 100644 (file)
--- a/README
+++ b/README
@@ -218,27 +218,33 @@ empty string).
        The assumption is that filenames are usually lowercase and
        variables usually uppercase.  Otherwise, use another syntax:
 
+&/             =>      sub/dir/                        or nothing
 &_             =>      sub_dir_                        or TOP_
-&=_            =>      sub_dir                         or TOP
+&.             =>      sub/dir                         or .
+       (This implies that `&./' works roughly like `&/', although
+       it can produce a needless `./')
 
-&/             =>      sub/dir/                        or nothing
-&=/            =>      sub/dir                         or .
+&=             =>      sub_dir                         or TOP
 
 &^lc           =>      $(top_srcdir)/sub/dir/lc
 &^/            =>      $(top_srcdir)/sub/dir/
+&^.            =>      $(top_srcdir)/sub/dir
 
 &~lc           =>      $(top_srcdir)/lc
 &~/            =>      $(top_srcdir)/
+&~.            =>      $(top_srcdir)
 
 In general:
-    =  return subdir without delimiter (not allowed with `^' `~')
     ^   pathname of this subdirectory in source tree
     ~   pathname of top level of source tree
-    /  terminates the escape (needed if next is not lwsp or space)
+    /  terminates the path escape } needed if next is
+    _   terminates the var escape  } not lwsp or space)
+    .   terminates path escape giving dir name (excluding /)
+    =  terminates var escape giving only prefix part (rarely needed)
   lwsp  starts multi-word processing (see below)
 
 So pathname syntax is a subset of:
-    '&' [ '^' | '~' ] [ lc | '/' ]
+    '&' [ '^' | '~' ] [ lc | '/' | '.' | '=' ]
 
 &&             =>      &&              for convenience in shell runes
 \&             =>      &               general escaping mechanism

diff --git a/generate b/generate
index ca54f944d13cf5011df25c77e4ca86f3c5af5821..ba66f8677fba472bc90a7ddd44b42693ab1b632a 100755 (executable)
--- a/generate
+++ b/generate
@@ -137,11 +137,14 @@ sub process_input_mk ($$$$$$$$$) {
     }
     $input_files{$f}++;
 
+    my %srcdirmap = (
+                 '^' => "\$(top_srcdir)${dir_suffix}",
+                 '~' => "\$(top_srcdir)",
+                   );
     my %pfxmap = (
                  ''  => $dir_prefix,
-                 '^' => "\$(top_srcdir)${dir_suffix}/",
-                 '~' => "\$(top_srcdir)/",
                 );
+    $pfxmap{$_} = $srcdirmap{$_}.'/' foreach keys %srcdirmap;
 
     while (<$input>) {
        if (s#^\s*$esc\:##) {
@@ -161,9 +164,10 @@ sub process_input_mk ($$$$$$$$$) {
            elsif (m{^(?=$caps_re)}) { o $var_prefix }
            elsif (s{^([~^]?)(?=$lc_re)}{}) { o $pfxmap{$1} }
            elsif (s{^_}{}) { o $var_prefix }
-           elsif (s{^=_}{}) { o $var_prefix }
+           elsif (s{^=}{}) { o $var_prefix_name }
            elsif (s{^([~^]?)/}{}) { o $pfxmap{$1} }
-           elsif (s{^=/}{}) { o $dir_name }
+           elsif (s{^\.}{}) { o $dir_name }
+           elsif (s{^([~^])\.}{}) { o $srcdirmap{$1} }
            elsif (s{^([~^]?)(?=[ \t])}{}) {
                my $prefix = $pfxmap{$1} // die;
                my $after='';