(system-include "carp_char.h")

(doc Char "is the single character data type.")
(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 to-byte (Fn [Char] Byte))
  (register from-byte (Fn [Byte] Char))
  (register copy (Fn [&Char] Char))

  (implements < Char.<)
  (implements > Char.>)
  (implements = Char.=)
  (implements copy Char.copy)
  (implements to-int Char.to-int)
  (implements from-int Char.from-int)

  (doc meaning "converts a numerical char into the appropriate number (e.g. from `\1` to `1`).")
  (defn meaning [char-ref]
    (let [c @char-ref]
      (case c
        \0 0
        \1 1
        \2 2
        \3 3
        \4 4
        \5 5
        \6 6
        \7 7
        \8 8
        \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 [] (the Char (from-int 0)))
  (implements zero Char.zero)
)

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

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