README: Document NEWQUOTE\$ in changequote

[subdirmk.git] / README

diff --git a/README b/README
index d15a9f42d9239b9c8271d7a2729f2b34d6bacaad..7ab1f2d4a3f0c94a38624c7e36f599de53d92a99 100644 (file)
--- a/README
+++ b/README
@@ -250,6 +250,10 @@ So pathname syntax is a subset of:
 
 &\&            =>      &               general escaping mechanism
 &\$            =>      $
+&\NEWLINE                              eats the newline and vanishes
+
+&$VARIABLE     =>      $(sub_dir_VARIABLE)     or $(TOP_VARIABLE)
+       VARIABLE is ASCII starting with a letter and matching \w+
 
 & thing thing... &
 &^ thing thing... &
@@ -265,33 +269,36 @@ 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
-               STUFF:changequote &     => set escape back to &
+               NEWQUOTENEWQUOTE        => NEWQUOTENEWQUOTE
+               NEWQUOTE\NEWQUOTE       => NEWQUOTE
+               NEWQUOTE\$              => $
+               NEWQUOTE:changequote &  set escape back to &
 
 &TARGETS_things
-       Handled specially.  If mentioned, declares that this
+       Handled specially.  If mentioned at the start of a line
+       (possibly following whitespace), declares that this
        subdir ought to have a target `things'.  The rule will be
                &/things:: $(&TARGETS_things)
 
@@ -305,9 +312,9 @@ So pathname syntax is a subset of:
        which recursively implies this directory's `things'.
 
        Must be spelled exactly &TARGETS_things.  &_TARGETS_things,
-       for example, is not magic.  But mentioning &TARGETS_things in
-       a #-comment *does* work because the & filter does not care
-       about comments.
+       for example, is not magic.  To make the target exist
+       without providing any prerequisites for it, write a line
+       containing just `&TARGETS_things +='.
 
        `all' is extra special: every directory has an `all'
        target, which corresponds to &TARGETS.