/* Grammar interface */

#ifndef Py_GRAMMAR_H
#define Py_GRAMMAR_H
#ifdef __cplusplus
extern "C" {
#endif

#include "bitset.h" /* Sigh... */

/* A label of an arc */

typedef struct {
 int lb_type;
 const char *lb_str;
} label;

#define EMPTY 0 /* Label number 0 is by definition the empty label */

/* A list of labels */

typedef struct {
 int ll_nlabels;
 const label *ll_label;
} labellist;

/* An arc from one state to another */

typedef struct {
 short a_lbl; /* Label of this arc */
 short a_arrow; /* State where this arc goes to */
} arc;

/* A state in a DFA */

typedef struct {
 int s_narcs;
 const arc *s_arc; /* Array of arcs */

 /* Optional accelerators */
 int s_lower; /* Lowest label index */
 int s_upper; /* Highest label index */
 int *s_accel; /* Accelerator */
 int s_accept; /* Nonzero for accepting state */
} state;

/* A DFA */

typedef struct {
 int d_type; /* Non-terminal this represents */
 char *d_name; /* For printing */
 int d_nstates;
 state *d_state; /* Array of states */
 bitset d_first;
} dfa;

/* A grammar */

typedef struct {
 int g_ndfas;
 const dfa *g_dfa; /* Array of DFAs */
 const labellist g_ll;
 int g_start; /* Start symbol of the grammar */
 int g_accel; /* Set if accelerators present */
} grammar;

/* FUNCTIONS */
const dfa *PyGrammar_FindDFA(grammar *g, int type);
const char *PyGrammar_LabelRepr(label *lb);
void PyGrammar_AddAccelerators(grammar *g);
void PyGrammar_RemoveAccelerators(grammar *);

#ifdef __cplusplus
}
#endif
#endif /* !Py_GRAMMAR_H */