/* 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;
 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;
 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;
 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_initial; /* Initial state */
 int d_nstates;
 state *d_state; /* Array of states */
 bitset d_first;
} dfa;

/* A grammar */

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

/* FUNCTIONS */

grammar *newgrammar(int start);
void freegrammar(grammar *g);
dfa *adddfa(grammar *g, int type, const char *name);
int addstate(dfa *d);
void addarc(dfa *d, int from, int to, int lbl);
dfa *PyGrammar_FindDFA(grammar *g, int type);

int addlabel(labellist *ll, int type, const char *str);
int findlabel(labellist *ll, int type, const char *str);
const char *PyGrammar_LabelRepr(label *lb);
void translatelabels(grammar *g);

void addfirstsets(grammar *g);

void PyGrammar_AddAccelerators(grammar *g);
void PyGrammar_RemoveAccelerators(grammar *);

void printgrammar(grammar *g, FILE *fp);
void printnonterminals(grammar *g, FILE *fp);

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