grammar.h

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/* 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);
dfa *adddfa(grammar *g, int type, 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, char *str);
int findlabel(labellist *ll, int type, char *str);
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 */