typedef struct Decl_Enum_Child Decl_Enum_Child;
typedef struct Decl_Function_Arg Decl_Function_Arg;
typedef struct Typespec Typespec;
typedef struct Decl Decl;
typedef struct Note Note;
typedef struct Stmt Stmt;

//-----------------------------------------------------------------------------
// Type specifier
//-----------------------------------------------------------------------------
typedef enum Typespec_Kind{
  TS_None,
  TS_Name,
  TS_Pointer,
  TS_Array,
  TS_Function,
}Typespec_Kind;

struct Typespec{
  Typespec_Kind kind;
  Typespec *next;
  Token *pos;
  union{
    Intern_String name;
    struct{
      Typespec *first;
      Typespec *last;
      Typespec *ret;
    }function_spec;
    struct{
      Typespec *base;
      Expr *size;
    }array_spec;
    Typespec *base;
  };
};

//-----------------------------------------------------------------------------
// Notes
//-----------------------------------------------------------------------------
struct Note{
  Token *pos;
  Intern_String name;
  Expr *expr;
  
  Note *next;
  Note *first;
  Note *last;
};

//-----------------------------------------------------------------------------
// Declarations
//-----------------------------------------------------------------------------
typedef enum Decl_Kind{
  DECL_None,
  DECL_Struct,
  DECL_Union,
  DECL_Enum,
  DECL_Variable,
  DECL_Typedef,
  DECL_Function,
  DECL_List,
}Decl_Kind;

typedef enum Decl_Struct_Kind{
  STRUCT_Base  ,
  STRUCT_Nested,
}Decl_Struct_Kind;

struct Decl_Function_Arg{
  Decl_Function_Arg *next;
  Intern_String name;
  Typespec *typespec;
  Token *pos;
};

struct Decl_Enum_Child{
  Decl_Enum_Child *next;
  Intern_String name;
  Token *pos;
  Expr *expr;
  
  Note *first_note;
  Note *last_note;
};

struct Decl{
  Decl_Kind kind;
  Decl *next;
  
  Intern_String name;
  Token *pos;
  
  Note *first_note;
  Note *last_note;
  
  union{
    struct{
      Decl_Enum_Child *first;
      Decl_Enum_Child *last;
      Typespec *typespec;
    }enum_decl;
    struct{
      Decl_Struct_Kind kind;
      Decl *first;
      Decl *last;
    } struct_decl;
    struct{
      Typespec *type;
      Expr *expr;
    }variable_decl;
    struct{
      Typespec *type;
    }typedef_decl;
    struct{
      Decl_Function_Arg *first;
      Decl_Function_Arg *last ;
      Typespec *ret;
    }function_decl;
    struct{
      Decl *first;
      Decl *last;
    }list;
  };
};

//-----------------------------------------------------------------------------
// Statements
//-----------------------------------------------------------------------------
typedef enum Stmt_Kind{
  STMT_None,
  STMT_Decl,
  STMT_Expr,
  STMT_Return,
  STMT_If,
  STMT_For,
}Stmt_Kind;

typedef struct Stmt_List Stmt_List;
struct Stmt_List{
  Stmt *first;
  Stmt *last;
};

typedef struct Stmt_If Stmt_If;
struct Stmt_If{
  Stmt_If *next;
  Expr *expr;
  union{ 
    struct{Stmt *first; Stmt *last;};
    Stmt_List *list;
  };
};

struct Stmt{
  Stmt_Kind kind;
  Stmt *next;
  union{
    Decl *decl;
    Expr *expr;
    Stmt_If *if_stmt;
    Stmt_List *list;
  };
};