source: python/vendor/Python-2.6.5/Parser/grammar1.c

/* Grammar subroutines needed by parser */

#include "Python.h"
#include "pgenheaders.h"
#include "grammar.h"
#include "token.h"

/* Return the DFA for the given type */

dfa *
PyGrammar_FindDFA(grammar *g, register int type)
{
        register dfa *d;
#if 1
        /* Massive speed-up */
        d = &g->g_dfa[type - NT_OFFSET];
        assert(d->d_type == type);
        return d;
#else
        /* Old, slow version */
        register int i;
        
        for (i = g->g_ndfas, d = g->g_dfa; --i >= 0; d++) {
                if (d->d_type == type)
                        return d;
        }
        assert(0);
        /* NOTREACHED */
#endif
}

char *
PyGrammar_LabelRepr(label *lb)
{
        static char buf[100];
        
        if (lb->lb_type == ENDMARKER)
                return "EMPTY";
        else if (ISNONTERMINAL(lb->lb_type)) {
                if (lb->lb_str == NULL) {
                        PyOS_snprintf(buf, sizeof(buf), "NT%d", lb->lb_type);
                        return buf;
                }
                else
                        return lb->lb_str;
        }
        else {
                if (lb->lb_str == NULL)
                        return _PyParser_TokenNames[lb->lb_type];
                else {
                        PyOS_snprintf(buf, sizeof(buf), "%.32s(%.32s)",
                                _PyParser_TokenNames[lb->lb_type], lb->lb_str);
                        return buf;
                }
        }
}