X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?p=subdirmk.git;a=blobdiff_plain;f=README;h=7ab1f2d4a3f0c94a38624c7e36f599de53d92a99;hp=d15a9f42d9239b9c8271d7a2729f2b34d6bacaad;hb=c1240cf57ddf3e5a78152bf4092db164f5255726;hpb=ad2d261d58a7718898ef7146d37b9c4b8e9083ca

diff --git a/README b/README
index d15a9f4..7ab1f2d 100644
--- 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.