?(?-) (This example tests various aspects of the implementation.)

<> (ghost) ()

?(?-) (Whitespace)

(a b c ) = (a b c) test
( a b c) = (a b c) test
(  a  b  c  ) = (a b c) test
(a b c  ( a b c )  ) = (a b c (a b c)) test

(ab cd () ghost) = (ab cd ()) test
(ab cd ghost ()) = (ab cd ()) test
(ab ghost cd ()) = (ab cd ()) test
(ghost ab cd ()) = (ab cd ()) test

?(?-) (Inline rules)

<> ((?x -> ?y)) (<> ?x ?y)
(nap -> (tap =))

nap tap test

?(?-) (Empty replacements)

<> (?x rightless/pop)
<> (?x pop) ()
<> (prefix/pop ?x) (ok)
<> (?x suffix/pop) (ok)

(abc rightless/pop) = () test
(prefix/pop foo) = (ok) test
(foo suffix/pop) = (ok) test
(abc def pop) = (abc) test
(ghost) = () test

?(?-) (Basic replacements)

<> (replace-name (foo)) ((bar) =)

replace-name (foo) (bar) test

?(?-) (Basic register setups)

<> (dup (?x)) (?x ?x)
<> (swap (?x ?y)) (?y ?x)
<> (compare (?x ?x ?x)) (#t)
<> (rotate (?x (?y (?z)))) (?y (?z (?x)))

(dup (abc)) = (abc abc) test
(swap (abc def)) = (def abc) test
compare (abc abc abc) = #t test
(rotate (abc (def (ghi)))) = (def (ghi (abc))) test

?(?-) (Empty register replacement)

<> (replace-empty ?x) (?y)

replace-empty abc = ?y test

?(?-) (Substring registers)

<> (connect ?x ?y ?z) (?x-?y?z)
<> (prefix-?x) (?x-suffix)

connect foo bar baz = foo-barbaz test
prefix-anything = anything-suffix test

?(?-) (Guards setups)

<> (join (String ?x) (String ?y)) ((?x ?y) =)

join (String abc) (String def) (abc def) test

?(?-) (Lambdas)

?((?x) ((?x ?x) =)) abc (abc abc) test
abc ?(?x) def = abc test

?(?-) (Explode)

<> (explode ?*) ((?*) =)

explode cow (c (o (w ()))) test
explode (12 34 45) (12 (34 (45 ()))) test

?(?-) (Implode)

<> (implode ?^) (?^ =)

implode (b (a (t ()))) bat test
implode (12 (34 (56 ()))) 123456 test

?(?-) (Test Primitives)

<> (?: print) (?:)
<> (?x = ?x test) (#ok\n print)
<> (?x = ?y test) (#fail\n print)

?(?-) (List reversal)

<> (reverse List () ?^) (?^)
<> (reverse (?*)) (reverse List (?*) ())
<> (reverse List (?x ?y) ?z) (reverse List ?y (?x ?z))

reverse (modal) = ladom test