cparse.c
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/*
cparse.c -- Racc Runtime Core
Copyright (c) 1999-2006 Minero Aoki
This library is free software.
You can distribute/modify this program under the same terms of ruby.
$originalId: cparse.c,v 1.8 2006/07/06 11:39:46 aamine Exp $
*/
#include "ruby/ruby.h"
#ifndef FALSE
#define FALSE 0
#endif
#ifndef TRUE
#define TRUE 1
#endif
/* -----------------------------------------------------------------------
Important Constants
----------------------------------------------------------------------- */
#define RACC_VERSION "1.4.5"
#define DEFAULT_TOKEN -1
#define ERROR_TOKEN 1
#define FINAL_TOKEN 0
#define vDEFAULT_TOKEN INT2FIX(DEFAULT_TOKEN)
#define vERROR_TOKEN INT2FIX(ERROR_TOKEN)
#define vFINAL_TOKEN INT2FIX(FINAL_TOKEN)
/* -----------------------------------------------------------------------
File Local Variables
----------------------------------------------------------------------- */
static VALUE RaccBug;
static VALUE CparseParams;
static ID id_yydebug;
static ID id_nexttoken;
static ID id_onerror;
static ID id_noreduce;
static ID id_errstatus;
static ID id_d_shift;
static ID id_d_reduce;
static ID id_d_accept;
static ID id_d_read_token;
static ID id_d_next_state;
static ID id_d_e_pop;
/* -----------------------------------------------------------------------
Utils
----------------------------------------------------------------------- */
/* For backward compatibility */
#ifndef ID2SYM
# define ID2SYM(i) ULONG2NUM(i)
#endif
#ifndef SYM2ID
# define SYM2ID(v) ((ID)NUM2ULONG(v))
#endif
#ifndef SYMBOL_P
# define SYMBOL_P(v) FIXNUM_P(v)
#endif
#ifndef LONG2NUM
# define LONG2NUM(i) INT2NUM(i)
#endif
static ID value_to_id _((VALUE v));
static inline long num_to_long _((VALUE n));
static ID
value_to_id(VALUE v)
{
if (! SYMBOL_P(v)) {
rb_raise(rb_eTypeError, "not symbol");
}
return SYM2ID(v);
}
static inline long
num_to_long(VALUE n)
{
return NUM2LONG(n);
}
#define AREF(s, idx) \
((0 <= idx && idx < RARRAY_LEN(s)) ? RARRAY_PTR(s)[idx] : Qnil)
/* -----------------------------------------------------------------------
Parser Stack Interfaces
----------------------------------------------------------------------- */
static VALUE get_stack_tail _((VALUE stack, long len));
static void cut_stack_tail _((VALUE stack, long len));
static VALUE
get_stack_tail(VALUE stack, long len)
{
if (len < 0) return Qnil; /* system error */
if (len > RARRAY_LEN(stack)) len = RARRAY_LEN(stack);
return rb_ary_new4(len, RARRAY_PTR(stack) + RARRAY_LEN(stack) - len);
}
static void
cut_stack_tail(VALUE stack, long len)
{
while (len > 0) {
rb_ary_pop(stack);
len--;
}
}
#define STACK_INIT_LEN 64
#define NEW_STACK() rb_ary_new2(STACK_INIT_LEN)
#define PUSH(s, i) rb_ary_store(s, RARRAY_LEN(s), i)
#define POP(s) rb_ary_pop(s)
#define LAST_I(s) \
((RARRAY_LEN(s) > 0) ? RARRAY_PTR(s)[RARRAY_LEN(s) - 1] : Qnil)
#define GET_TAIL(s, len) get_stack_tail(s, len)
#define CUT_TAIL(s, len) cut_stack_tail(s, len)
/* -----------------------------------------------------------------------
struct cparse_params
----------------------------------------------------------------------- */
struct cparse_params {
VALUE value_v; /* VALUE version of this struct */
VALUE parser; /* parser object */
int lex_is_iterator;
VALUE lexer; /* scanner object */
ID lexmid; /* name of scanner method (must be an iterator) */
/* State transition tables (immutable)
Data structure is from Dragon Book 4.9 */
/* action table */
VALUE action_table;
VALUE action_check;
VALUE action_default;
VALUE action_pointer;
/* goto table */
VALUE goto_table;
VALUE goto_check;
VALUE goto_default;
VALUE goto_pointer;
long nt_base; /* NonTerminal BASE index */
VALUE reduce_table; /* reduce data table */
VALUE token_table; /* token conversion table */
/* parser stacks and parameters */
VALUE state;
long curstate;
VALUE vstack;
VALUE tstack;
VALUE t;
long shift_n;
long reduce_n;
long ruleno;
long errstatus; /* nonzero in error recovering mode */
long nerr; /* number of error */
int use_result_var;
VALUE retval; /* return value of parser routine */
long fin; /* parse result status */
#define CP_FIN_ACCEPT 1
#define CP_FIN_EOT 2
#define CP_FIN_CANTPOP 3
int debug; /* user level debug */
int sys_debug; /* system level debug */
long i; /* table index */
};
/* -----------------------------------------------------------------------
Parser Main Routines
----------------------------------------------------------------------- */
static VALUE racc_cparse _((VALUE parser, VALUE arg, VALUE sysdebug));
static VALUE racc_yyparse _((VALUE parser, VALUE lexer, VALUE lexmid,
VALUE arg, VALUE sysdebug));
static void call_lexer _((struct cparse_params *v));
static VALUE lexer_i _((VALUE block_args, VALUE data, VALUE self));
static VALUE assert_array _((VALUE a));
static long assert_integer _((VALUE n));
static VALUE assert_hash _((VALUE h));
static VALUE initialize_params _((VALUE vparams, VALUE parser, VALUE arg,
VALUE lexer, VALUE lexmid));
static void cparse_params_mark _((void *ptr));
static void parse_main _((struct cparse_params *v,
VALUE tok, VALUE val, int resume));
static void extract_user_token _((struct cparse_params *v,
VALUE block_args, VALUE *tok, VALUE *val));
static void shift _((struct cparse_params* v, long act, VALUE tok, VALUE val));
static int reduce _((struct cparse_params* v, long act));
static VALUE reduce0 _((VALUE block_args, VALUE data, VALUE self));
#ifdef DEBUG
# define D_puts(msg) if (v->sys_debug) puts(msg)
# define D_printf(fmt,arg) if (v->sys_debug) printf(fmt,arg)
#else
# define D_puts(msg)
# define D_printf(fmt,arg)
#endif
static VALUE
racc_cparse(VALUE parser, VALUE arg, VALUE sysdebug)
{
volatile VALUE vparams;
struct cparse_params *v;
vparams = Data_Make_Struct(CparseParams, struct cparse_params,
cparse_params_mark, -1, v);
D_puts("starting cparse");
v->sys_debug = RTEST(sysdebug);
vparams = initialize_params(vparams, parser, arg, Qnil, Qnil);
v->lex_is_iterator = FALSE;
parse_main(v, Qnil, Qnil, 0);
return v->retval;
}
static VALUE
racc_yyparse(VALUE parser, VALUE lexer, VALUE lexmid, VALUE arg, VALUE sysdebug)
{
volatile VALUE vparams;
struct cparse_params *v;
vparams = Data_Make_Struct(CparseParams, struct cparse_params,
cparse_params_mark, -1, v);
v->sys_debug = RTEST(sysdebug);
D_puts("start C yyparse");
vparams = initialize_params(vparams, parser, arg, lexer, lexmid);
v->lex_is_iterator = TRUE;
D_puts("params initialized");
parse_main(v, Qnil, Qnil, 0);
call_lexer(v);
if (!v->fin) {
rb_raise(rb_eArgError, "%s() is finished before EndOfToken",
rb_id2name(v->lexmid));
}
return v->retval;
}
#ifdef HAVE_RB_BLOCK_CALL
static void
call_lexer(struct cparse_params *v)
{
rb_block_call(v->lexer, v->lexmid, 0, NULL, lexer_i, v->value_v);
}
#else
static VALUE
lexer_iter(VALUE data)
{
struct cparse_params *v;
Data_Get_Struct(data, struct cparse_params, v);
rb_funcall(v->lexer, v->lexmid, 0);
return Qnil;
}
static void
call_lexer(struct cparse_params *v)
{
rb_iterate(lexer_iter, v->value_v, lexer_i, v->value_v);
}
#endif
static VALUE
lexer_i(VALUE block_args, VALUE data, VALUE self)
{
struct cparse_params *v;
VALUE tok, val;
Data_Get_Struct(data, struct cparse_params, v);
if (v->fin)
rb_raise(rb_eArgError, "extra token after EndOfToken");
extract_user_token(v, block_args, &tok, &val);
parse_main(v, tok, val, 1);
if (v->fin && v->fin != CP_FIN_ACCEPT)
rb_iter_break();
return Qnil;
}
static VALUE
assert_array(VALUE a)
{
Check_Type(a, T_ARRAY);
return a;
}
static VALUE
assert_hash(VALUE h)
{
Check_Type(h, T_HASH);
return h;
}
static long
assert_integer(VALUE n)
{
return NUM2LONG(n);
}
static VALUE
initialize_params(VALUE vparams, VALUE parser, VALUE arg, VALUE lexer, VALUE lexmid)
{
struct cparse_params *v;
Data_Get_Struct(vparams, struct cparse_params, v);
v->value_v = vparams;
v->parser = parser;
v->lexer = lexer;
if (! NIL_P(lexmid))
v->lexmid = value_to_id(lexmid);
v->debug = RTEST(rb_ivar_get(parser, id_yydebug));
Check_Type(arg, T_ARRAY);
if (!(13 <= RARRAY_LEN(arg) && RARRAY_LEN(arg) <= 14))
rb_raise(RaccBug, "[Racc Bug] wrong arg.size %ld", RARRAY_LEN(arg));
v->action_table = assert_array (RARRAY_PTR(arg)[ 0]);
v->action_check = assert_array (RARRAY_PTR(arg)[ 1]);
v->action_default = assert_array (RARRAY_PTR(arg)[ 2]);
v->action_pointer = assert_array (RARRAY_PTR(arg)[ 3]);
v->goto_table = assert_array (RARRAY_PTR(arg)[ 4]);
v->goto_check = assert_array (RARRAY_PTR(arg)[ 5]);
v->goto_default = assert_array (RARRAY_PTR(arg)[ 6]);
v->goto_pointer = assert_array (RARRAY_PTR(arg)[ 7]);
v->nt_base = assert_integer(RARRAY_PTR(arg)[ 8]);
v->reduce_table = assert_array (RARRAY_PTR(arg)[ 9]);
v->token_table = assert_hash (RARRAY_PTR(arg)[10]);
v->shift_n = assert_integer(RARRAY_PTR(arg)[11]);
v->reduce_n = assert_integer(RARRAY_PTR(arg)[12]);
if (RARRAY_LEN(arg) > 13) {
v->use_result_var = RTEST(RARRAY_PTR(arg)[13]);
}
else {
v->use_result_var = TRUE;
}
v->tstack = v->debug ? NEW_STACK() : Qnil;
v->vstack = NEW_STACK();
v->state = NEW_STACK();
v->curstate = 0;
PUSH(v->state, INT2FIX(0));
v->t = INT2FIX(FINAL_TOKEN + 1); /* must not init to FINAL_TOKEN */
v->nerr = 0;
v->errstatus = 0;
rb_ivar_set(parser, id_errstatus, LONG2NUM(v->errstatus));
v->retval = Qnil;
v->fin = 0;
v->lex_is_iterator = FALSE;
rb_iv_set(parser, "@vstack", v->vstack);
if (v->debug) {
rb_iv_set(parser, "@tstack", v->tstack);
}
else {
rb_iv_set(parser, "@tstack", Qnil);
}
return vparams;
}
static void
cparse_params_mark(void *ptr)
{
struct cparse_params *v = (struct cparse_params*)ptr;
rb_gc_mark(v->value_v);
rb_gc_mark(v->parser);
rb_gc_mark(v->lexer);
rb_gc_mark(v->action_table);
rb_gc_mark(v->action_check);
rb_gc_mark(v->action_default);
rb_gc_mark(v->action_pointer);
rb_gc_mark(v->goto_table);
rb_gc_mark(v->goto_check);
rb_gc_mark(v->goto_default);
rb_gc_mark(v->goto_pointer);
rb_gc_mark(v->reduce_table);
rb_gc_mark(v->token_table);
rb_gc_mark(v->state);
rb_gc_mark(v->vstack);
rb_gc_mark(v->tstack);
rb_gc_mark(v->t);
rb_gc_mark(v->retval);
}
static void
extract_user_token(struct cparse_params *v, VALUE block_args,
VALUE *tok, VALUE *val)
{
if (NIL_P(block_args)) {
/* EOF */
*tok = Qfalse;
*val = rb_str_new("$", 1);
return;
}
if (TYPE(block_args) != T_ARRAY) {
rb_raise(rb_eTypeError,
"%s() %s %s (must be Array[2])",
v->lex_is_iterator ? rb_id2name(v->lexmid) : "next_token",
v->lex_is_iterator ? "yielded" : "returned",
rb_class2name(CLASS_OF(block_args)));
}
if (RARRAY_LEN(block_args) != 2) {
rb_raise(rb_eArgError,
"%s() %s wrong size of array (%ld for 2)",
v->lex_is_iterator ? rb_id2name(v->lexmid) : "next_token",
v->lex_is_iterator ? "yielded" : "returned",
RARRAY_LEN(block_args));
}
*tok = AREF(block_args, 0);
*val = AREF(block_args, 1);
}
#define SHIFT(v,act,tok,val) shift(v,act,tok,val)
#define REDUCE(v,act) do {\
switch (reduce(v,act)) { \
case 0: /* normal */ \
break; \
case 1: /* yyerror */ \
goto user_yyerror; \
case 2: /* yyaccept */ \
D_puts("u accept"); \
goto accept; \
default: \
break; \
} \
} while (0)
static void
parse_main(struct cparse_params *v, VALUE tok, VALUE val, int resume)
{
long i; /* table index */
long act; /* action type */
VALUE act_value; /* action type, VALUE version */
int read_next = 1; /* true if we need to read next token */
VALUE tmp;
if (resume)
goto resume;
while (1) {
D_puts("");
D_puts("---- enter new loop ----");
D_puts("");
D_printf("(act) k1=%ld\n", v->curstate);
tmp = AREF(v->action_pointer, v->curstate);
if (NIL_P(tmp)) goto notfound;
D_puts("(act) pointer[k1] ok");
i = NUM2LONG(tmp);
D_printf("read_next=%d\n", read_next);
if (read_next && (v->t != vFINAL_TOKEN)) {
if (v->lex_is_iterator) {
D_puts("resuming...");
if (v->fin) rb_raise(rb_eArgError, "token given after EOF");
v->i = i; /* save i */
return;
resume:
D_puts("resumed");
i = v->i; /* load i */
}
else {
D_puts("next_token");
tmp = rb_funcall(v->parser, id_nexttoken, 0);
extract_user_token(v, tmp, &tok, &val);
}
/* convert token */
v->t = rb_hash_aref(v->token_table, tok);
if (NIL_P(v->t)) {
v->t = vERROR_TOKEN;
}
D_printf("(act) t(k2)=%ld\n", NUM2LONG(v->t));
if (v->debug) {
rb_funcall(v->parser, id_d_read_token,
3, v->t, tok, val);
}
}
read_next = 0;
i += NUM2LONG(v->t);
D_printf("(act) i=%ld\n", i);
if (i < 0) goto notfound;
act_value = AREF(v->action_table, i);
if (NIL_P(act_value)) goto notfound;
act = NUM2LONG(act_value);
D_printf("(act) table[i]=%ld\n", act);
tmp = AREF(v->action_check, i);
if (NIL_P(tmp)) goto notfound;
if (NUM2LONG(tmp) != v->curstate) goto notfound;
D_printf("(act) check[i]=%ld\n", NUM2LONG(tmp));
D_puts("(act) found");
act_fixed:
D_printf("act=%ld\n", act);
goto handle_act;
notfound:
D_puts("(act) not found: use default");
act_value = AREF(v->action_default, v->curstate);
act = NUM2LONG(act_value);
goto act_fixed;
handle_act:
if (act > 0 && act < v->shift_n) {
D_puts("shift");
if (v->errstatus > 0) {
v->errstatus--;
rb_ivar_set(v->parser, id_errstatus, LONG2NUM(v->errstatus));
}
SHIFT(v, act, v->t, val);
read_next = 1;
}
else if (act < 0 && act > -(v->reduce_n)) {
D_puts("reduce");
REDUCE(v, act);
}
else if (act == -(v->reduce_n)) {
goto error;
error_recovered:
; /* goto label requires stmt */
}
else if (act == v->shift_n) {
D_puts("accept");
goto accept;
}
else {
rb_raise(RaccBug, "[Racc Bug] unknown act value %ld", act);
}
if (v->debug) {
rb_funcall(v->parser, id_d_next_state,
2, LONG2NUM(v->curstate), v->state);
}
}
/* not reach */
accept:
if (v->debug) rb_funcall(v->parser, id_d_accept, 0);
v->retval = RARRAY_PTR(v->vstack)[0];
v->fin = CP_FIN_ACCEPT;
return;
error:
D_printf("error detected, status=%ld\n", v->errstatus);
if (v->errstatus == 0) {
v->nerr++;
rb_funcall(v->parser, id_onerror,
3, v->t, val, v->vstack);
}
user_yyerror:
if (v->errstatus == 3) {
if (v->t == vFINAL_TOKEN) {
v->retval = Qfalse;
v->fin = CP_FIN_EOT;
return;
}
read_next = 1;
}
v->errstatus = 3;
rb_ivar_set(v->parser, id_errstatus, LONG2NUM(v->errstatus));
/* check if we can shift/reduce error token */
D_printf("(err) k1=%ld\n", v->curstate);
D_printf("(err) k2=%d (error)\n", ERROR_TOKEN);
while (1) {
tmp = AREF(v->action_pointer, v->curstate);
if (NIL_P(tmp)) goto error_pop;
D_puts("(err) pointer[k1] ok");
i = NUM2LONG(tmp) + ERROR_TOKEN;
D_printf("(err) i=%ld\n", i);
if (i < 0) goto error_pop;
act_value = AREF(v->action_table, i);
if (NIL_P(act_value)) {
D_puts("(err) table[i] == nil");
goto error_pop;
}
act = NUM2LONG(act_value);
D_printf("(err) table[i]=%ld\n", act);
tmp = AREF(v->action_check, i);
if (NIL_P(tmp)) {
D_puts("(err) check[i] == nil");
goto error_pop;
}
if (NUM2LONG(tmp) != v->curstate) {
D_puts("(err) check[i] != k1");
goto error_pop;
}
D_puts("(err) found: can handle error token");
break;
error_pop:
D_puts("(err) act not found: can't handle error token; pop");
if (RARRAY_LEN(v->state) <= 1) {
v->retval = Qnil;
v->fin = CP_FIN_CANTPOP;
return;
}
POP(v->state);
POP(v->vstack);
v->curstate = num_to_long(LAST_I(v->state));
if (v->debug) {
POP(v->tstack);
rb_funcall(v->parser, id_d_e_pop,
3, v->state, v->tstack, v->vstack);
}
}
/* shift/reduce error token */
if (act > 0 && act < v->shift_n) {
D_puts("e shift");
SHIFT(v, act, ERROR_TOKEN, val);
}
else if (act < 0 && act > -(v->reduce_n)) {
D_puts("e reduce");
REDUCE(v, act);
}
else if (act == v->shift_n) {
D_puts("e accept");
goto accept;
}
else {
rb_raise(RaccBug, "[Racc Bug] unknown act value %ld", act);
}
goto error_recovered;
}
static void
shift(struct cparse_params *v, long act, VALUE tok, VALUE val)
{
PUSH(v->vstack, val);
if (v->debug) {
PUSH(v->tstack, tok);
rb_funcall(v->parser, id_d_shift,
3, tok, v->tstack, v->vstack);
}
v->curstate = act;
PUSH(v->state, LONG2NUM(v->curstate));
}
static int
reduce(struct cparse_params *v, long act)
{
VALUE code;
v->ruleno = -act * 3;
code = rb_catch("racc_jump", reduce0, v->value_v);
v->errstatus = num_to_long(rb_ivar_get(v->parser, id_errstatus));
return NUM2INT(code);
}
static VALUE
reduce0(VALUE val, VALUE data, VALUE self)
{
struct cparse_params *v;
VALUE reduce_to, reduce_len, method_id;
long len;
ID mid;
VALUE tmp, tmp_t = Qundef, tmp_v = Qundef;
long i, k1, k2;
VALUE goto_state;
Data_Get_Struct(data, struct cparse_params, v);
reduce_len = RARRAY_PTR(v->reduce_table)[v->ruleno];
reduce_to = RARRAY_PTR(v->reduce_table)[v->ruleno+1];
method_id = RARRAY_PTR(v->reduce_table)[v->ruleno+2];
len = NUM2LONG(reduce_len);
mid = value_to_id(method_id);
/* call action */
if (len == 0) {
tmp = Qnil;
if (mid != id_noreduce)
tmp_v = rb_ary_new();
if (v->debug)
tmp_t = rb_ary_new();
}
else {
if (mid != id_noreduce) {
tmp_v = GET_TAIL(v->vstack, len);
tmp = RARRAY_PTR(tmp_v)[0];
}
else {
tmp = RARRAY_PTR(v->vstack)[ RARRAY_LEN(v->vstack) - len ];
}
CUT_TAIL(v->vstack, len);
if (v->debug) {
tmp_t = GET_TAIL(v->tstack, len);
CUT_TAIL(v->tstack, len);
}
CUT_TAIL(v->state, len);
}
if (mid != id_noreduce) {
if (v->use_result_var) {
tmp = rb_funcall(v->parser, mid,
3, tmp_v, v->vstack, tmp);
}
else {
tmp = rb_funcall(v->parser, mid,
2, tmp_v, v->vstack);
}
}
/* then push result */
PUSH(v->vstack, tmp);
if (v->debug) {
PUSH(v->tstack, reduce_to);
rb_funcall(v->parser, id_d_reduce,
4, tmp_t, reduce_to, v->tstack, v->vstack);
}
/* calculate transition state */
if (RARRAY_LEN(v->state) == 0)
rb_raise(RaccBug, "state stack unexpectedly empty");
k2 = num_to_long(LAST_I(v->state));
k1 = num_to_long(reduce_to) - v->nt_base;
D_printf("(goto) k1=%ld\n", k1);
D_printf("(goto) k2=%ld\n", k2);
tmp = AREF(v->goto_pointer, k1);
if (NIL_P(tmp)) goto notfound;
i = NUM2LONG(tmp) + k2;
D_printf("(goto) i=%ld\n", i);
if (i < 0) goto notfound;
goto_state = AREF(v->goto_table, i);
if (NIL_P(goto_state)) {
D_puts("(goto) table[i] == nil");
goto notfound;
}
D_printf("(goto) table[i]=%ld (goto_state)\n", NUM2LONG(goto_state));
tmp = AREF(v->goto_check, i);
if (NIL_P(tmp)) {
D_puts("(goto) check[i] == nil");
goto notfound;
}
if (tmp != LONG2NUM(k1)) {
D_puts("(goto) check[i] != table[i]");
goto notfound;
}
D_printf("(goto) check[i]=%ld\n", NUM2LONG(tmp));
D_puts("(goto) found");
transit:
PUSH(v->state, goto_state);
v->curstate = NUM2LONG(goto_state);
return INT2FIX(0);
notfound:
D_puts("(goto) not found: use default");
/* overwrite `goto-state' by default value */
goto_state = AREF(v->goto_default, k1);
goto transit;
}
/* -----------------------------------------------------------------------
Ruby Interface
----------------------------------------------------------------------- */
void
Init_cparse(void)
{
VALUE Racc, Parser;
ID id_racc = rb_intern("Racc");
if (rb_const_defined(rb_cObject, id_racc)) {
Racc = rb_const_get(rb_cObject, id_racc);
Parser = rb_const_get_at(Racc, rb_intern("Parser"));
}
else {
Racc = rb_define_module("Racc");
Parser = rb_define_class_under(Racc, "Parser", rb_cObject);
}
rb_define_private_method(Parser, "_racc_do_parse_c", racc_cparse, 2);
rb_define_private_method(Parser, "_racc_yyparse_c", racc_yyparse, 4);
rb_define_const(Parser, "Racc_Runtime_Core_Version_C",
rb_str_new2(RACC_VERSION));
rb_define_const(Parser, "Racc_Runtime_Core_Id_C",
rb_str_new2("$originalId: cparse.c,v 1.8 2006/07/06 11:39:46 aamine Exp $"));
CparseParams = rb_define_class_under(Racc, "CparseParams", rb_cObject);
RaccBug = rb_eRuntimeError;
id_yydebug = rb_intern("@yydebug");
id_nexttoken = rb_intern("next_token");
id_onerror = rb_intern("on_error");
id_noreduce = rb_intern("_reduce_none");
id_errstatus = rb_intern("@racc_error_status");
id_d_shift = rb_intern("racc_shift");
id_d_reduce = rb_intern("racc_reduce");
id_d_accept = rb_intern("racc_accept");
id_d_read_token = rb_intern("racc_read_token");
id_d_next_state = rb_intern("racc_next_state");
id_d_e_pop = rb_intern("racc_e_pop");
}