 @@ -1,54 +1,64 @@
 path=':/bin:/tmp::/:.:/no/such/dir:.'
 path='/bin:/tmp:/:/no/such/dir'
 path='/bin:/tmp:/:/no/such/dir'
 path='/bin':'/tmp':'/':'/no/such/dir'
 path='/bin':'/tmp':'/':'/no/such/dir'
 path_/usr/xbin=/opt/xbin/
 paths=/bin /tmp / /no/such/dir /opt/xbin
 PATHS=/BIN /TMP / /NO/SUCH/DIR /OPT/XBIN
 The answer is 42
 dirname of 'a/b/c def a.b.c a.b/c a a.a .gitignore a a.a' is 'a/b . . a.b . . . . .'
 basename of 'a/b/c def a.b.c a.b/c a a.a .gitignore a a.a' is 'c def a.b.c c a a.a .gitignore a a.a'
 suffix of 'a/b/c def a.b.c a.b/c a a.a .gitignore a a.a' is 'c b/c a gitignore a'
 root of 'a/b/c def a.b.c a.b/c a a.a .gitignore a a.a' is 'a/b/c def a.b a a a  a a'
 S:
 C:
 @:
 S:empty
 C:empty
 @:
 :a b b c:
 :a b b c:
 : b c:
 :a c:
 :x__ 3 x__ 3:
 :a b b c:
 :a b b c:
 : b c:
 make: RE substitution error: (details omitted)
 make: Unclosed substitution for  (, missing)
 :C,word,____,:Q}:
 :a c:
 :x__ 3 x__ 3:
 :+one+ +two+ +three+:
 mod-at-resolve:w1d2d3w w2i3w w1i2d3 2i${RES3}w w1d2d3 2i${RES3} 1i${RES2}w:
 mod-at-dollar:(1) (2) (3).
 mod-at-dollar:(1) (2) (3).
 mod-at-dollar:() () ().
 mod-subst-dollar:$1:
 mod-subst-dollar:$2:
 mod-subst-dollar:$3:
 mod-subst-dollar:$4:
 mod-subst-dollar:$5:
 mod-subst-dollar:$6:
 mod-subst-dollar:$7:
 mod-subst-dollar:$8:
 mod-subst-dollar:U8:
 mod-subst-dollar:$$$$:
 mod-loop-dollar:1:
 mod-loop-dollar:${word}:
 mod-loop-dollar:$3$:
 mod-loop-dollar:$${word}$:
 mod-loop-dollar:$$5$$:
 mod-loop-dollar:$$${word}$$:
 mod-C-limits:00-ok:1 2323 45456
 mod-C-limits:11-missing:1 6
 mod-C-limits:11-ok:1 22 446
 make: No subexpression \2
 make: No subexpression \2
 make: No subexpression \2
 make: No subexpression \2
 mod-C-limits:22-missing:1 6
 mod-C-limits:22-missing:1 6
 mod-C-limits:22-ok:1 33 556
 exit status 0

 @@ -1,135 +1,144 @@
-# $Id: modmisc.mk,v 1.13 2020/07/19 15:16:22 rillig Exp $
+# $Id: modmisc.mk,v 1.14 2020/07/19 17:24:22 rillig Exp $
+#
 # miscellaneous modifier tests
 # do not put any dirs in this list which exist on some
 # but not all target systems - an exists() check is below.
 path=:/bin:/tmp::/:.:/no/such/dir:.
 # strip cwd from path.
 MOD_NODOT=S/:/ /g:N.:ts:
 # and decorate, note that $'s need to be doubled. Also note that
 # the modifier_variable can be used with other modifiers.
 MOD_NODOTX=S/:/ /g:N.:@d@'$$d'@
 # another mod - pretend it is more interesting
 MOD_HOMES=S,/home/,/homes/,
 MOD_OPT=@d@$${exists($$d):?$$d:$${d:S,/usr,/opt,}}@
 MOD_SEP=S,:, ,g
 all:	modvar modvarloop modsysv mod-HTE emptyvar undefvar
 all:	mod-S mod-C mod-at-varname mod-at-resolve mod-at-dollar
 all:	mod-subst-dollar mod-loop-dollar
 all:	mod-C-limits
 modsysv:
 	@echo "The answer is ${libfoo.a:L:libfoo.a=42}"
 modvar:
 	@echo "path='${path}'"
 	@echo "path='${path:${MOD_NODOT}}'"
 	@echo "path='${path:S,home,homes,:${MOD_NODOT}}'"
 	@echo "path=${path:${MOD_NODOTX}:ts:}"
 	@echo "path=${path:${MOD_HOMES}:${MOD_NODOTX}:ts:}"
 .for d in ${path:${MOD_SEP}:N.} /usr/xbin
 path_$d?= ${d:${MOD_OPT}:${MOD_HOMES}}/
 paths+= ${d:${MOD_OPT}:${MOD_HOMES}}
 .endfor
 modvarloop:
 	@echo "path_/usr/xbin=${path_/usr/xbin}"
 	@echo "paths=${paths}"
 	@echo "PATHS=${paths:tu}"
 PATHNAMES=	a/b/c def a.b.c a.b/c a a.a .gitignore a a.a
 mod-HTE:
 	@echo "dirname of '"${PATHNAMES:Q}"' is '"${PATHNAMES:H:Q}"'"
 	@echo "basename of '"${PATHNAMES:Q}"' is '"${PATHNAMES:T:Q}"'"
 	@echo "suffix of '"${PATHNAMES:Q}"' is '"${PATHNAMES:E:Q}"'"
 	@echo "root of '"${PATHNAMES:Q}"' is '"${PATHNAMES:R:Q}"'"
 # When a modifier is applied to the "" variable, the result is discarded.
 emptyvar:
 	@echo S:${:S,^$,empty,}
 	@echo C:${:C,^$,empty,}
 	@echo @:${:@var@${var}@}
 # The :U modifier turns even the "" variable into something that has a value.
 # The resulting variable is empty, but is still considered to contain a
 # single empty word. This word can be accessed by the :S and :C modifiers,
 # but not by the :@ modifier since it explicitly skips empty words.
 undefvar:
 	@echo S:${:U:S,^$,empty,}
 	@echo C:${:U:C,^$,empty,}
 	@echo @:${:U:@var@empty@}
 mod-S:
 	@echo :${:Ua b b c:S,a b,,:Q}:
 	@echo :${:Ua b b c:S,a b,,1:Q}:
 	@echo :${:Ua b b c:S,a b,,W:Q}:
 	@echo :${:Ua b b c:S,b,,g:Q}:
 	@echo :${:U1 2 3 1 2 3:S,1 2,___,Wg:S,_,x,:Q}:
 mod-C:
 	@echo :${:Ua b b c:C,a b,,:Q}:
 	@echo :${:Ua b b c:C,a b,,1:Q}:
 	@echo :${:Ua b b c:C,a b,,W:Q}:
 	@echo :${:Uword1 word2:C,****,____,g:C,word,____,:Q}:
 	@echo :${:Ua b b c:C,b,,g:Q}:
 	@echo :${:U1 2 3 1 2 3:C,1 2,___,Wg:C,_,x,:Q}:
 # In the :@ modifier, the name of the loop variable can even be generated
 # dynamically.  There's no practical use-case for this, and hopefully nobody
 # will ever depend on this, but technically it's possible.
 mod-at-varname:
 	@echo :${:Uone two three:@${:Ubar:S,b,v,}@+${var}+@:Q}:
 # The :@ modifier resolves the variables a little more often than expected.
 # In particular, it resolves _all_ variables from the context, and not only
 # the loop variable (in this case v).
+#
 # The d means direct reference, the i means indirect reference.
 RESOLVE=	${RES1} $${RES1}
 RES1=		1d${RES2} 1i$${RES2}
 RES2=		2d${RES3} 2i$${RES3}
 RES3=		3
 mod-at-resolve:
 	@echo $@:${RESOLVE:@v@w${v}w@:Q}:
 # As of 2020-07-19, the variable name of the :@ modifier may end with one
 # or two dollar signs, which are silently ignored.  There's no point in
 # allowing a dollar sign in that position.
 mod-at-dollar:
 	@echo $@:${1 2 3:L:@v$@($v)@:Q}.
 	@echo $@:${1 2 3:L:@v$$@($v)@:Q}.
 	@echo $@:${1 2 3:L:@v$$$@($v)@:Q}.
 # No matter how many dollar characters there are, they all get merged
 # into a single dollar by the :S modifier.
 mod-subst-dollar:
 	@echo $@:${:U1:S,^,$,:Q}:
 	@echo $@:${:U2:S,^,$$,:Q}:
 	@echo $@:${:U3:S,^,$$$,:Q}:
 	@echo $@:${:U4:S,^,$$$$,:Q}:
 	@echo $@:${:U5:S,^,$$$$$,:Q}:
 	@echo $@:${:U6:S,^,$$$$$$,:Q}:
 	@echo $@:${:U7:S,^,$$$$$$$,:Q}:
 	@echo $@:${:U8:S,^,$$$$$$$$,:Q}:
 # This generates no dollar at all:
 	@echo $@:${:UU8:S,^,${:U$$$$$$$$},:Q}:
 # Here is an alternative way to generate dollar characters.
 # It's unexpectedly complicated though.
 	@echo $@:${:U:range=5:ts\x24:C,[0-9],,g:Q}:
 # Demonstrate that it is possible to generate dollar characters using the
 # :@ modifier.
+#
 # These are edge cases that could have resulted in a parse error as well
 # since the $@ at the end could have been interpreted as a variable, which
 # would mean a missing closing @ delimiter.
 mod-loop-dollar:
 	@echo $@:${:U1:@word@${word}$@:Q}:
 	@echo $@:${:U2:@word@$${word}$$@:Q}:
 	@echo $@:${:U3:@word@$$${word}$$$@:Q}:
 	@echo $@:${:U4:@word@$$$${word}$$$$@:Q}:
 	@echo $@:${:U5:@word@$$$$${word}$$$$$@:Q}:
 	@echo $@:${:U6:@word@$$$$$${word}$$$$$$@:Q}:
 mod-C-limits:
 	@echo $@:00-ok:${:U1 23 456:C,..,\0\0,:Q}
 	@echo $@:11-missing:${:U1 23 456:C,..,\1\1,:Q}
 	@echo $@:11-ok:${:U1 23 456:C,(.).,\1\1,:Q}
 	@echo $@:22-missing:${:U1 23 456:C,..,\2\2,:Q}
 	@echo $@:22-missing:${:U1 23 456:C,(.).,\2\2,:Q}
 	@echo $@:22-ok:${:U1 23 456:C,(.)(.),\2\2,:Q}