module type Fn = sig
  val sentence_segment: string -> 'a -> 'a
  val sentence_s: 'a -> 'a
  val sentence_e: 'a -> 'a
end

open Text_parse.Parser
open Text_parse.Syntax
open Text_parse.Cursor

module Sentence_segment (F : Fn) = struct
  let s _cursor = printable
  let e cursor = function
    | '.' -> char_at cursor 1 = ' ' || newline (char_at cursor 1) (* todo punctuations *)
    | '\n' -> char_at cursor 1 = '\n'
    | _ when cursor.pos + 1 = cursor.right_boundary -> true
    | _ when char_at cursor 1 = '[' -> true
    | _ when char_at cursor 1 = '*' -> true
    | _ when char_at cursor 1 = '_' -> true
    | _ when char_at cursor 1 = '/' -> true
    | _ when char_at cursor 1 = '`' -> true
    | _ when char_at cursor 1 = '<' -> true
    | _ -> false
  let at = at s e
  let parse cur acc = F.sentence_segment (segment_string cur) acc
end

module Sentence (F : Fn) = struct
  let s _cursor = printable
  let e cursor = function
    | '.' -> char_at cursor 1 = ' ' (* todo punctuations *)
    | '\n' -> char_at cursor 1 = '\n'
    | _ -> false
  let at = at s e
  let subsyntaxes = [| |]
  let parse cur acc = F.sentence_s acc |> parse subsyntaxes cur |> F.sentence_e
end