some regular expression usage examples

Ported from https://docs.racket-lang.org/reference/regexp.html

Thanks Kinnard Hockenhull for the questions and feedback about regular
expressions in Arc.

lib/re.arc.t

@@ -0,0 +1,116 @@
+(require 'lib/re.arc)
+
+(suite re-match
+       (suite simple-regex
+              (test ex1
+                    (assert-same '("a")
+                                 (re-match (re "a|b") "cat")))
+              (test ex2
+                    (assert-same '("a")
+                                 (re-match (re "[at]") "cat")))
+              (test ex3
+                    (assert-same '("caaat")
+                                 (re-match (re "ca*[at]") "caaat")))
+              (test ex4
+                    (assert-same '("caaat")
+                                 (re-match (re "ca+[at]") "caaat")))
+              (test ex5
+                    (assert-same '("ct")
+                                 (re-match (re "ca?t?") "ct")))
+              (test ex6
+                    (assert-same '("ca")
+                                 (re-match (re "ca*?[at]") "caaat")))
+              (test ex7
+                    (assert-same '("caa" "c" "aa")
+                                 (re-match (re "(c*)(a*)") "caat")))
+              (test ex8
+                    (assert-same '("t")
+                                 (re-match (re "[^ca]") "caat")))
+              (test ex9
+                    (assert-same '("cat" "a")
+                                 (re-match (re ".(.).") "cat")))
+              (test ex10
+                    (assert-same '("c")
+                                 (re-match (re "^a|^c") "cat")))
+              (test ex11
+                    (assert-same '("t")
+                                 (re-match (re "a$|t$") "cat")))
+              (test ex12
+                    (assert-same '("|")
+                                 (re-match (re "\\|") "c|t")))
+              (test ex13
+                    (assert-same '("ca")
+                                 (re-match (re "[a-f]*") "cat")))
+              (test ex14
+                    (assert-same '("]")
+                                 (re-match (re "[]]") "c]t")))
+              (test ex15
+                    (assert-same '("-")
+                                 (re-match (re "[-]") "c-t")))
+              (test ex16
+                    (assert-same '("[a]")
+                                 (re-match (re "[]a[]+") "c[a]t")))
+              (test ex17
+                    (assert-same '("a^")
+                                 (re-match (re "[a^]+") "ca^t")))
+              (test ex18
+                    (assert-same '("na")
+                                 (re-match (re ".a(?=p)") "cat nap")))
+              (test ex19
+                    (assert-same '("na")
+                                 (re-match (re ".a(?!t)") "cat nap")))
+              (test ex20
+                    (assert-same '("ap")
+                                 (re-match (re "(?<=n)a.") "cat nap")))
+              (test ex21
+                    (assert-same '("ap")
+                                 (re-match (re "(?<!c)a.") "cat nap")))
+              (test ex22
+                    (assert-same '("Ap")
+                                 (re-match (re "(?i:a)[tp]") "cAT nAp")))
+              (test ex23
+                    (assert-same '("ab")
+                                 (re-match (re "(?(?<=c)a|b)+") "cabal")))
+       )
+
+       (suite perl-regex
+              (test ex1
+                    (assert-same '("caa")
+                                 (re-match (pre "ca{2}") "caaat")))
+              (test ex2
+                    (assert-same '("caat")
+                                 (re-match (pre "ca{2,}t") "catcaat")))
+              (test ex3
+                    (assert-same '("cat")
+                                 (re-match (pre "ca{,2}t") "caaatcat")))
+              (test ex4
+                    (assert-same '("cat")
+                                 (re-match (pre "ca{1,2}t") "caaatcat")))
+              (test ex5
+                    (assert-same '("caat" "a")
+                                 (re-match (pre "c(.)\\1t") "caat")))
+              (test ex6
+                    (assert-same '("t ")
+                                 (re-match (pre ".\\b.") "cat in hat")))
+              (test ex7
+                    (assert-same '("ca")
+                                 (re-match (pre ".\\B.") "cat in hat")))
+              (test ex8
+                    (assert-same '("a")
+                                 (re-match (pre "\\p{Ll}") "Cat")))
+              (test ex9
+                    (assert-same '("!")
+                                 (re-match (pre "\\P{Ll}") "cat!")))
+              (test ex10
+                    (assert-same '("1ca")
+                                 (re-match (pre "[a-f\\d]*") "1cat")))
+              (test ex11
+                    (assert-same '(" h")
+                                 (re-match (pre " [\\w]") "cat hat")))
+              (test ex12
+                    (assert-same '("t\n")
+                                 (re-match (pre "t[\\s]") "cat\nhat")))
+              (test ex13
+                    (assert-same '("at")
+                                 (re-match (pre "[[:lower:]]+") "Cat")))
+       ))

tests.arc

@@ -17,6 +17,7 @@
     lib/html.arc.t
     lib/ns.arc.t
     lib/queue.arc.t
+    lib/re.arc.t
     lib/spliceable-list.arc.t
     lib/strings.arc.t
     lib/streams.arc.t