(system-include "carp_char.h")

(defmodule Char
  (register = (Fn [Char Char] Bool))
  (register < (Fn [Char Char] Bool))
  (register > (Fn [Char Char] Bool))
  (register to-int (Fn [Char] Int))
  (register from-int (Fn [Int] Char))
  (register copy (Fn [&Char] Char))

  (doc meaning "converts a numerical char into the appropriate number (e.g. from `\1` to `1`).")
  (defn meaning [char-ref]
    (cond
      (= @char-ref \0) 0
      (= @char-ref \1) 1
      (= @char-ref \2) 2
      (= @char-ref \3) 3
      (= @char-ref \4) 4
      (= @char-ref \5) 5
      (= @char-ref \6) 6
      (= @char-ref \7) 7
      (= @char-ref \8) 8
      (= @char-ref \9) 9
      -1))

  (doc lower-case? "tests whether a character is lower case.")
  (defn lower-case? [c]
    (and (<= \a c) (<= c \z)))

  (doc upper-case? "tests whether a character is upper case.")
  (defn upper-case? [c]
    (and (<= \A c) (<= c \Z)))

  (doc alpha? "tests whether a character is alphabetical.")
  (defn alpha? [c]
    (or (lower-case? c) (upper-case? c)))

  (doc num? "tests whether a character is numerical.")
  (defn num? [c]
    (and (<= \0 c) (<= c \9)))

  (doc alphanum? "tests whether a character is alphanumerical.")
  (defn alphanum? [c]
    (or (alpha? c) (num? c)))

  (defn zero []
    (from-int 0))
)

(defmodule CharRef
  (defn = [a b]
    (Char.= @a @b))
  (defn < [a b]
    (Char.< @a @b))
  (defn > [a b]
    (Char.> @a @b))
)

(defmodule PtrChar
  (register str (Fn [(Ptr Char)] String)))