(ns Regex
  "Elixir Regex module — regular expression operations (wraps Erlang :re).

   In CljElixir: (Regex/match? ~r/pattern/ string), etc.
   Regex literals use ~r/pattern/flags syntax.")

(defn compile
  "Compiles a regex pattern string. Returns {:ok regex} or {:error reason}.
   (Regex/compile \"^hello\") ;=> {:ok ~r/^hello/}
   (Regex/compile \"hello\" \"i\") ;=> case-insensitive"
  ([source])
  ([source opts]))

(defn compile!
  "Compiles a regex. Raises on invalid pattern.
   (Regex/compile! \"^hello\") ;=> ~r/^hello/"
  ([source])
  ([source opts]))

(defn match?
  "Returns true if `string` matches `regex`.
   (Regex/match? ~r/\\d+/ \"hello123\") ;=> true"
  [regex string])

(defn run
  "Runs the regex against `string`. Returns list of matches or nil.
   (Regex/run ~r/(\\w+)@(\\w+)/ \"user@host\") ;=> [\"user@host\" \"user\" \"host\"]
   (Regex/run ~r/\\d+/ \"hello\") ;=> nil"
  ([regex string])
  ([regex string opts]))

(defn scan
  "Scans the string for all matches.
   (Regex/scan ~r/\\d+/ \"a1b2c3\") ;=> [[\"1\"] [\"2\"] [\"3\"]]"
  ([regex string])
  ([regex string opts]))

(defn named-captures
  "Returns a map of named captures.
   (Regex/named-captures ~r/(?P<year>\\d{4})-(?P<month>\\d{2})/ \"2024-03\")
   ;=> %{\"year\" => \"2024\", \"month\" => \"03\"}"
  ([regex string])
  ([regex string opts]))

(defn replace
  "Replaces regex matches in `string` with `replacement`.
   (Regex/replace ~r/\\d+/ \"a1b2\" \"X\") ;=> \"aXbX\"
   (Regex/replace ~r/(\\w+)/ \"hello\" (fn [match] (String/upcase match)))"
  ([regex string replacement])
  ([regex string replacement opts]))

(defn split
  "Splits `string` by `regex`.
   (Regex/split ~r/\\s+/ \"hello  world\") ;=> [\"hello\" \"world\"]
   (Regex/split ~r/,/ \"a,b,c\" :parts 2) ;=> [\"a\" \"b,c\"]"
  ([regex string])
  ([regex string opts]))

(defn source
  "Returns the source string of a compiled regex.
   (Regex/source ~r/hello/) ;=> \"hello\""
  [regex])

(defn opts
  "Returns the options string of a compiled regex.
   (Regex/opts ~r/hello/i) ;=> \"i\""
  [regex])

(defn re-pattern
  "Returns the underlying compiled pattern."
  [regex])

(defn names
  "Returns a list of named capture group names.
   (Regex/names ~r/(?P<name>\\w+)/) ;=> [\"name\"]"
  [regex])

(defn escape
  "Escapes a string for use in a regex.
   (Regex/escape \"hello.world\") ;=> \"hello\\\\.world\""
  [string])

(defn regex?
  "Returns true if `term` is a compiled regex."
  [term])