Syntax: only some directives' RHS should be &-expanded

[subdirmk.git] / README

diff --git a/README b/README
index 67ce6cc17c8fd3755ecddf39a675a073850f11ff..63e41881b9674d440978d4f1076190f2df7fef3d 100644 (file)
--- a/README
+++ b/README
@@ -247,7 +247,12 @@ So pathname syntax is a subset of:
     '&' [ '^' | '~' ] [ lc | '/' | '.' | '=' ]
 
 &&             =>      &&              for convenience in shell runes
-\&             =>      &               general escaping mechanism
+
+&\&            =>      &               general escaping mechanism
+&\$            =>      $
+
+&$VARIABLE     =>      $(sub_dir_VARIABLE)     or $(TOP_VARIABLE)
+       VARIABLE is ASCII starting with a letter and matching \w+
 
 & thing thing... &
 &^ thing thing... &
@@ -263,30 +268,31 @@ So pathname syntax is a subset of:
        recognised at start of line only (possibly after lwsp)
        args are processed for &
 
-&:include filename             filename should usually be foo.sd.mk
+&:include filename             filename should usually be [&]foo.sd.mk
 &:-include filename            tolerate nonexistent file
        filenames are relative to $(top_srcdir)
+       RHS is &-expanded
 
 &!<lwsp>       disables & until EOL (and then disappears)
 
 &#     delete everything to end of line
        (useful if the RHS contains unrecognised & constructions)
 
-&:changequote STUFF
-       changes the escape sequence from & to literally STUFF
-       STUFF may be any series of of non-whitespace characters,
+&:changequote NEWQUOTE
+       changes the escape sequence from & to literally NEWQUOTE
+       NEWQUOTE may be any series of of non-whitespace characters,
        and is terminated by EOL or lwsp.  The whole line is
        discarded.
 
-       After this, write STUFF instead of &, everywhere.
+       After this, write NEWQUOTE instead of &, everywhere.
        The effect is global and lasts until the next setting.
        It takes effect on &:include'd files too, so maybe set
        it back before using &:include.
 
        Notably
-               STUFFSTUFF              => STUFFSTUFF
-               \STUFF                  => STUFF
-               STUFF:changequote &     => set escape back to &
+               NEWQUOTENEWQUOTE        => NEWQUOTENEWQUOTE
+               NEWQUOTE\NEWQUOTE       => NEWQUOTE
+               NEWQUOTE:changequote &  set escape back to &
 
 &TARGETS_things
        Handled specially.  If mentioned, declares that this