/* Lists of symbols for Bison

   Copyright (C) 2002, 2005, 2006, 2007, 2009 Free Software Foundation,
   Inc.

   This file is part of Bison, the GNU Compiler Compiler.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef SYMLIST_H_
# define SYMLIST_H_

# include "location.h"
# include "scan-code.h"
# include "symtab.h"
# include "named-ref.h"

/* A list of symbols, used during the parsing to store the rules.  */
typedef struct symbol_list
{
  /**
   * Whether this node contains a symbol, a semantic type, a \c <*>, or a
   * \c <>.
   */
  enum {
    SYMLIST_SYMBOL, SYMLIST_TYPE,
    SYMLIST_DEFAULT_TAGGED, SYMLIST_DEFAULT_TAGLESS
  } content_type;
  union {
    /**
     * The symbol or \c NULL iff
     * <tt>symbol_list::content_type = SYMLIST_SYMBOL</tt>.
     */
    symbol *sym;
    /**
     * The semantic type iff <tt>symbol_list::content_type = SYMLIST_TYPE</tt>.
     */
    uniqstr type_name;
  } content;
  location location;

  /* Proper location of the symbol, not all the rule */
  location sym_loc;

  /* If this symbol is the generated lhs for a midrule but this is the rule in
     whose rhs it appears, MIDRULE = a pointer to that midrule.  */
  struct symbol_list *midrule;

  /* If this symbol is the generated lhs for a midrule and this is that
     midrule, MIDRULE_PARENT_RULE = a pointer to the rule in whose rhs it
     appears, and MIDRULE_PARENT_RHS_INDEX = its rhs index (1-origin) in the
     parent rule.  */
  struct symbol_list *midrule_parent_rule;
  int midrule_parent_rhs_index;

  /* The action is attached to the LHS of a rule, but action properties for
   * each RHS are also stored here.  */
  code_props action_props;

  /* Precedence/associativity.  */
  symbol *ruleprec;
  int dprec;
  int merger;
  location merger_declaration_location;

  /* Named reference. */
  named_ref *named_ref;

  /* The list.  */
  struct symbol_list *next;
} symbol_list;


/** Create a list containing \c sym at \c loc.  */
symbol_list *symbol_list_sym_new (symbol *sym, location loc);

/** Create a list containing \c type_name at \c loc.  */
symbol_list *symbol_list_type_new (uniqstr type_name, location loc);

/** Create a list containing a \c <*> at \c loc.  */
symbol_list *symbol_list_default_tagged_new (location loc);
/** Create a list containing a \c <> at \c loc.  */
symbol_list *symbol_list_default_tagless_new (location loc);

/** Print this list.

  \pre For every node \c n in the list, <tt>n->content_type =
  SYMLIST_SYMBOL</tt>.  */
void symbol_list_syms_print (const symbol_list *l, FILE *f);

/** Prepend \c node to \c list.  */
symbol_list *symbol_list_prepend (symbol_list *list, symbol_list *node);

/** Free \c list, but not the items it contains.  */
void symbol_list_free (symbol_list *list);

/** Return the length of \c l. */
int symbol_list_length (symbol_list const *l);

/** Get item \c n in symbol list \c l.  */
symbol_list *symbol_list_n_get (symbol_list *l, int n);

/* Get the data type (alternative in the union) of the value for
   symbol N in rule RULE.  */
uniqstr symbol_list_n_type_name_get (symbol_list *l, location loc, int n);

/* Check whether the node is a border element of a rule. */
bool symbol_list_null (symbol_list *node);

/** Set the \c \%destructor for \c node as \c code at \c loc.  */
void symbol_list_destructor_set (symbol_list *node, char const *code,
                                 location loc);

/** Set the \c \%printer for \c node as \c code at \c loc.  */
void symbol_list_printer_set (symbol_list *node, char const *code,
                              location loc);

#endif /* !SYMLIST_H_ */