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/*$Id: iparam.h,v 1.2 2000/09/19 19:00:46 lpd Exp $ */
/* Definitions and interface for interpreter parameter list implementations */
/* Requires ialloc.h, istack.h */

#ifndef iparam_INCLUDED
#  define iparam_INCLUDED

#include "gsparam.h"

/*
 * This file defines the interface to iparam.c, which provides
 * several implementations of the parameter dictionary interface
 * defined in gsparam.h:
 *      - an implementation using dictionary objects;
 *      - an implementation using name/value pairs in an array;
 *      - an implementation using name/value pairs on a stack.
 *
 * When reading ('putting'), these implementations keep track of
 * which parameters have been referenced and which have caused errors.
 * The results array contains 0 for a parameter that has not been accessed,
 * 1 for a parameter accessed without error, or <0 for an error.
 */

typedef struct iparam_loc_s {
    ref *pvalue;		/* (actually const) */
    int *presult;
} iparam_loc;

#define iparam_list_common\
    gs_param_list_common;\
    gs_ref_memory_t *ref_memory; /* a properly typed copy of memory */\
    union {\
      struct {	/* reading */\
	int (*read)(P3(iparam_list *, const ref *, iparam_loc *));\
	ref policies;	/* policy dictionary or null */\
	bool require_all;	/* if true, require all params to be known */\
      } r;\
      struct {		/* writing */\
	int (*write)(P3(iparam_list *, const ref *, const ref *));\
	ref wanted;		/* desired keys or null */\
      } w;\
    } u;\
    int (*enumerate)(P4(iparam_list *, gs_param_enumerator_t *, gs_param_key_t *, ref_type *));\
    int *results;		/* (only used when reading, 0 when writing) */\
    uint count;		/* # of key/value pairs */\
    bool int_keys		/* if true, keys are integers */
typedef struct iparam_list_s iparam_list;
struct iparam_list_s {
    iparam_list_common;
};

typedef struct dict_param_list_s {
    iparam_list_common;
    ref dict;			/* dictionary or array */
} dict_param_list;
typedef struct array_param_list_s {
    iparam_list_common;
    ref *bot;
    ref *top;
} array_param_list;

/* For stack lists, the bottom of the list is just above a mark. */
typedef struct stack_param_list_s {
    iparam_list_common;
    ref_stack_t *pstack;
    uint skip;			/* # of top items to skip (reading only) */
} stack_param_list;

/* Procedural interface */
/*
 * For dict_param_list_read (only), the second parameter may be NULL,
 * equivalent to an empty dictionary.
 * The 3rd (const ref *) parameter is the policies dictionary when reading,
 * or the key selection dictionary when writing; it may be NULL in either case.
 * If the bool parameter is true, if there are any unqueried parameters,
 * the commit procedure will return an e_undefined error.
 */
int dict_param_list_read(P5(dict_param_list *, const ref * /*t_dictionary */ ,
			    const ref *, bool, gs_ref_memory_t *));
int dict_param_list_write(P4(dict_param_list *, ref * /*t_dictionary */ ,
			     const ref *, gs_ref_memory_t *));
int array_indexed_param_list_read(P5(dict_param_list *, const ref * /*t_*array */ ,
				     const ref *, bool, gs_ref_memory_t *));
int array_indexed_param_list_write(P4(dict_param_list *, ref * /*t_*array */ ,
				      const ref *, gs_ref_memory_t *));
int array_param_list_read(P6(array_param_list *, ref *, uint,
			     const ref *, bool, gs_ref_memory_t *));
int stack_param_list_read(P6(stack_param_list *, ref_stack_t *, uint,
			     const ref *, bool, gs_ref_memory_t *));
int stack_param_list_write(P4(stack_param_list *, ref_stack_t *,
			      const ref *, gs_ref_memory_t *));

#define iparam_list_release(plist)\
  gs_free_object((plist)->memory, (plist)->results, "iparam_list_release")

#endif /* iparam_INCLUDED */
