module Quox.Unicode

import Generics.Derive


%default total
%language ElabReflection


namespace Letter
  public export
  data Letter = Uppercase | Lowercase | Titlecase | Modifier | Other
  %runElab derive "Letter" [Generic, Meta, Eq, Ord, DecEq, Show]

namespace Mark
  public export
  data Mark = NonSpacing | SpacingCombining | Enclosing
  %runElab derive "Mark" [Generic, Meta, Eq, Ord, DecEq, Show]

namespace Number
  public export
  data Number = Decimal | Letter | Other
  %runElab derive "Number" [Generic, Meta, Eq, Ord, DecEq, Show]

namespace Punctuation
  public export
  data Punctuation = Connector | Dash | Open | Close
                   | InitialQuote | FinalQuote | Other
  %runElab derive "Punctuation" [Generic, Meta, Eq, Ord, DecEq, Show]

namespace Symbol
  public export
  data Symbol = Math | Currency | Modifier | Other
  %runElab derive "Symbol" [Generic, Meta, Eq, Ord, DecEq, Show]

namespace Separator
  public export
  data Separator = Space | Line | Paragraph
  %runElab derive "Separator" [Generic, Meta, Eq, Ord, DecEq, Show]

namespace Other
  public export
  data Other = Control | Format | Surrogate | PrivateUse | NotAssigned
  %runElab derive "Other" [Generic, Meta, Eq, Ord, DecEq, Show]


public export
data GeneralCategory
= Letter      Letter
| Mark        Mark
| Number      Number
| Punctuation Punctuation
| Symbol      Symbol
| Separator   Separator
| Other       Other
%runElab derive "GeneralCategory" [Generic, Meta, Eq, Ord, DecEq, Show]


private
%foreign "scheme:(lambda (c) (symbol->string (char-general-category c)))"
prim__genCat : Char -> String

export
genCat : Char -> GeneralCategory
genCat ch = assert_total $
  case prim__genCat ch of
       "Lu" => Letter      Uppercase
       "Ll" => Letter      Lowercase
       "Lt" => Letter      Titlecase
       "Lm" => Letter      Modifier
       "Lo" => Letter      Other
       "Mn" => Mark        NonSpacing
       "Mc" => Mark        SpacingCombining
       "Me" => Mark        Enclosing
       "Nd" => Number      Decimal
       "Nl" => Number      Letter
       "No" => Number      Other
       "Pc" => Punctuation Connector
       "Pd" => Punctuation Dash
       "Ps" => Punctuation Open
       "Pe" => Punctuation Close
       "Pi" => Punctuation InitialQuote
       "Pf" => Punctuation FinalQuote
       "Po" => Punctuation Other
       "Sm" => Symbol      Math
       "Sc" => Symbol      Currency
       "Sk" => Symbol      Modifier
       "So" => Symbol      Other
       "Zs" => Separator   Space
       "Zl" => Separator   Line
       "Zp" => Separator   Paragraph
       "Cc" => Other       Control
       "Cf" => Other       Format
       "Cs" => Other       Surrogate
       "Co" => Other       PrivateUse
       "Cn" => Other       NotAssigned


export
isIdStart : Char -> Bool
isIdStart ch =
  case genCat ch of
       Letter _ => True
       Number _ => not ('0' <= ch && ch <= '9')
       _        => False

export
isIdCont : Char -> Bool
isIdCont ch =
  isIdStart ch || ch == '\'' ||
  case genCat ch of
       Mark   _ => True
       Number _ => True
       _        => False

export
isIdConnector : Char -> Bool
isIdConnector ch =
  case genCat ch of Punctuation Connector => True; _ => False


export
isSymChar : Char -> Bool
isSymChar ch =
  case genCat ch of
       Symbol      _     => True
       Punctuation Dash  => True
       Punctuation Other => True
       _                 => False

export
isWhitespace : Char -> Bool
isWhitespace ch =
  ch == '\t' || ch == '\r' || ch == '\n' ||
  case genCat ch of Separator _ => True; _ => False


export
%foreign "scheme:string-normalize-nfc"
normalizeNfc : String -> String