spec: regular expressions (make-regexp/regexp-match/regexp-replace + split)

Adds 9 regexp primitives to stdlib.regexp. OCaml: SxRegexp(src,flags,Re.re)
using Re.Pcre; $&/$1 capture expansion in replace. JS: native RegExp
with SxRegexp wrapper; regexp-match returns {:match :start :end :groups}.
32 tests in test-regexp.sx, all pass on both hosts.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

spec/tests/test-regexp.sx

@@ -0,0 +1,191 @@
+;; ==========================================================================
+;; test-regexp.sx — Tests for regexp primitives
+;; ==========================================================================
+
+;; --------------------------------------------------------------------------
+;; make-regexp / regexp?
+;; --------------------------------------------------------------------------
+
+(defsuite
+  "regexp:create"
+  (deftest "make-regexp returns regexp" (assert (regexp? (make-regexp "abc"))))
+  (deftest
+    "make-regexp with flags"
+    (assert (regexp? (make-regexp "[a-z]+" "i"))))
+  (deftest "regexp? true for regexp" (assert (regexp? (make-regexp "x"))))
+  (deftest "regexp? false for string" (assert (not (regexp? "abc"))))
+  (deftest "regexp? false for nil" (assert (not (regexp? nil))))
+  (deftest
+    "regexp-source"
+    (assert= (regexp-source (make-regexp "hello")) "hello"))
+  (deftest
+    "regexp-flags"
+    (assert= (regexp-flags (make-regexp "x" "im")) "im"))
+  (deftest
+    "regexp-flags empty string"
+    (assert= (regexp-flags (make-regexp "x")) "")))
+
+;; --------------------------------------------------------------------------
+;; regexp-match — basic
+;; --------------------------------------------------------------------------
+
+(defsuite
+  "regexp:match"
+  (deftest
+    "match returns dict"
+    (let
+      ((m (regexp-match (make-regexp "hel+o") "hello world")))
+      (assert (dict? m))))
+  (deftest
+    "match :match key"
+    (let
+      ((m (regexp-match (make-regexp "hel+o") "say hello")))
+      (assert= (get m "match") "hello")))
+  (deftest
+    "match :start key"
+    (let
+      ((m (regexp-match (make-regexp "lo") "hello")))
+      (assert= (get m "start") 3)))
+  (deftest
+    "match :end key"
+    (let
+      ((m (regexp-match (make-regexp "lo") "hello")))
+      (assert= (get m "end") 5)))
+  (deftest
+    "no match returns nil"
+    (assert-nil (regexp-match (make-regexp "xyz") "hello")))
+  (deftest
+    "match at start"
+    (let
+      ((m (regexp-match (make-regexp "^hel") "hello")))
+      (assert= (get m "start") 0)))
+  (deftest
+    "match digit pattern"
+    (let
+      ((m (regexp-match (make-regexp "[0-9]+") "abc 123 def")))
+      (assert= (get m "match") "123"))))
+
+;; --------------------------------------------------------------------------
+;; regexp-match — groups
+;; --------------------------------------------------------------------------
+
+(defsuite
+  "regexp:groups"
+  (deftest
+    "no capture groups → empty list"
+    (let
+      ((m (regexp-match (make-regexp "hello") "hello world")))
+      (assert= (length (get m "groups")) 0)))
+  (deftest
+    "one capture group"
+    (let
+      ((m (regexp-match (make-regexp "([0-9]+)") "price: 42")))
+      (assert= (first (get m "groups")) "42")))
+  (deftest
+    "two capture groups"
+    (let
+      ((m (regexp-match (make-regexp "([a-z]+)=([0-9]+)") "x=10")))
+      (let
+        ((gs (get m "groups")))
+        (assert
+          (and (= (first gs) "x") (= (first (rest gs)) "10")))))))
+
+;; --------------------------------------------------------------------------
+;; regexp-match-all
+;; --------------------------------------------------------------------------
+
+(defsuite
+  "regexp:match-all"
+  (deftest
+    "match-all returns list"
+    (let
+      ((ms (regexp-match-all (make-regexp "[0-9]+") "1 and 2 and 3")))
+      (assert (list? ms))))
+  (deftest
+    "match-all count"
+    (assert=
+      (length (regexp-match-all (make-regexp "[0-9]+") "1 and 2 and 3"))
+      3))
+  (deftest
+    "match-all first match"
+    (let
+      ((ms (regexp-match-all (make-regexp "[0-9]+") "10 20 30")))
+      (assert= (get (first ms) "match") "10")))
+  (deftest
+    "match-all empty when no match"
+    (assert=
+      (length (regexp-match-all (make-regexp "xyz") "hello"))
+      0)))
+
+;; --------------------------------------------------------------------------
+;; regexp-replace / regexp-replace-all
+;; --------------------------------------------------------------------------
+
+(defsuite
+  "regexp:replace"
+  (deftest
+    "replace first match"
+    (assert= (regexp-replace (make-regexp "o+") "foobar boo" "0") "f0bar boo"))
+  (deftest
+    "replace no match returns original"
+    (assert= (regexp-replace (make-regexp "xyz") "hello" "X") "hello"))
+  (deftest
+    "replace-all all matches"
+    (assert= (regexp-replace-all (make-regexp "o") "foo boo" "0") "f00 b00"))
+  (deftest
+    "replace with $& (whole match)"
+    (assert=
+      (regexp-replace (make-regexp "[0-9]+") "price 42" "[$&]")
+      "price [42]"))
+  (deftest
+    "replace-all removes digits"
+    (assert=
+      (regexp-replace-all (make-regexp "[0-9]") "a1b2c3" "")
+      "abc")))
+
+;; --------------------------------------------------------------------------
+;; regexp-split
+;; --------------------------------------------------------------------------
+
+(defsuite
+  "regexp:split"
+  (deftest
+    "split on whitespace"
+    (let
+      ((parts (regexp-split (make-regexp " +") "hello world foo")))
+      (assert= (length parts) 3)))
+  (deftest
+    "split first part"
+    (let
+      ((parts (regexp-split (make-regexp ",") "a,b,c")))
+      (assert= (first parts) "a")))
+  (deftest
+    "split last part"
+    (let
+      ((parts (regexp-split (make-regexp ",") "a,b,c")))
+      (assert= (first (rest (rest parts))) "c")))
+  (deftest
+    "split no match → single element"
+    (let
+      ((parts (regexp-split (make-regexp ",") "hello")))
+      (assert= (length parts) 1))))
+
+;; --------------------------------------------------------------------------
+;; flags
+;; --------------------------------------------------------------------------
+
+(defsuite
+  "regexp:flags"
+  (deftest
+    "case-insensitive flag"
+    (let
+      ((m (regexp-match (make-regexp "HELLO" "i") "hello world")))
+      (assert (not (nil? m)))))
+  (deftest
+    "case-sensitive without flag"
+    (assert-nil (regexp-match (make-regexp "HELLO") "hello world")))
+  (deftest
+    "multiline ^ matches line starts"
+    (let
+      ((ms (regexp-match-all (make-regexp "^[a-z]" "m") "a\nb\nc")))
+      (assert= (length ms) 3))))