all: show the rules in user actions
Akim Demaille <[email protected]>
| Newsgroups | gmane.comp.parsers.bison.patches |
|---|---|
| Message-ID | <[email protected]> |
commit d64d7b9f2aa6196e92eaa2da4b6ce2e9c77e47ac Author: Akim Demaille <[email protected]> Date: Fri Jun 5 16:51:59 2020 +0200 all: show the rules in user actions For instance, in the case of Bison's own parser: - case 40: + case 40: /* grammar_declaration: "%code" "identifier" "{...}" */ { muscle_percent_code_grow ((yyvsp[-1].ID), (yylsp[-1]), translate_code_braceless ((yyvsp[0].BRACED_CODE), (yylsp[0])), (yylsp[0])); code_scanner_last_string_free (); } break; * data/skeletons/c.m4: Modified. * data/skeletons/d.m4: Modified. * data/skeletons/java.m4: Modified. * src/output.c (output_escaped): New. (quoted_output): Use it, and rename as... (output_quoted): this. Adjust dependencies. (rule_output): New. (user_actions_output): Use it. * data/skeletons/c.m4, data/skeletons/d.m4, data/skeletons/java.m4 (b4_case): Add support for $3, an optional comment. diff --git a/data/skeletons/c.m4 b/data/skeletons/c.m4 index 6bf1e660..2452ed2e 100644 --- a/data/skeletons/c.m4 +++ b/data/skeletons/c.m4 @@ -666,10 +666,10 @@ m4_define([b4_sync_start], [[#]line $1 $2]) ## User actions. ## ## -------------- ## -# b4_case(LABEL, STATEMENTS) -# -------------------------- +# b4_case(LABEL, STATEMENTS, [COMMENTS]) +# -------------------------------------- m4_define([b4_case], -[ case $1: +[ case $1:m4_ifval([$3], [ b4_comment([$3])]) $2 b4_syncline([@oline@], [@ofile@])dnl break;]) diff --git a/data/skeletons/d.m4 b/data/skeletons/d.m4 index c19f7d86..edb0c49e 100644 --- a/data/skeletons/d.m4 +++ b/data/skeletons/d.m4 @@ -213,9 +213,9 @@ m4_define([b4_declare_symbol_enum], -# b4-case(ID, CODE) -# ----------------- -m4_define([b4_case], [ case $1: +# b4-case(ID, CODE, [COMMENTS]) +# ----------------------------- +m4_define([b4_case], [ case $1:m4_ifval([$3], [ b4_comment([$3])]) $2 break;]) diff --git a/data/skeletons/java.m4 b/data/skeletons/java.m4 index af38ccc3..e4e2fad8 100644 --- a/data/skeletons/java.m4 +++ b/data/skeletons/java.m4 @@ -262,11 +262,11 @@ m4_define([b4_declare_symbol_enum], -# b4_case(ID, CODE) -# ----------------- +# b4_case(ID, CODE, [COMMENTS]) +# ----------------------------- # We need to fool Java's stupid unreachable code detection. m4_define([b4_case], -[ case $1: +[ case $1:m4_ifval([$3], [ b4_comment([$3])]) if (yyn == $1) $2; break; diff --git a/src/output.c b/src/output.c index 11f57f8d..509502dd 100644 --- a/src/output.c +++ b/src/output.c @@ -107,10 +107,8 @@ GENERATE_MUSCLE_INSERT_TABLE (muscle_insert_state_number_table, state_number) `----------------------------------------------------------------*/ static void -quoted_output (FILE *out, char const *cp) +output_escaped (FILE *out, const char *cp) { - fprintf (out, "[["); - for (; *cp; cp++) switch (*cp) { @@ -120,7 +118,13 @@ quoted_output (FILE *out, char const *cp) case ']': fputs ("@}", out); break; default: fputc (*cp, out); break; } +} +static void +output_quoted (FILE *out, char const *cp) +{ + fprintf (out, "[["); + output_escaped (out, cp); fprintf (out, "]]"); } @@ -132,7 +136,7 @@ quoted_output (FILE *out, char const *cp) static void string_output (FILE *out, char const *string) { - quoted_output (out, quotearg_style (c_quoting_style, string)); + output_quoted (out, quotearg_style (c_quoting_style, string)); } @@ -474,6 +478,21 @@ symbol_numbers_output (FILE *out) | Output the user reduction actions to OUT. | `-------------------------------------------*/ +static void +rule_output (const rule *r, FILE *out) +{ + output_escaped (out, r->lhs->symbol->tag); + fputc (':', out); + if (0 <= *r->rhs) + for (item_number *rhsp = r->rhs; 0 <= *rhsp; ++rhsp) + { + fputc (' ', out); + output_escaped (out, symbols[*rhsp]->tag); + } + else + fputs (" %empty", out); +} + static void user_actions_output (FILE *out) { @@ -492,9 +511,11 @@ user_actions_output (FILE *out) string_output (out, rules[r].action_loc.start.file); fprintf (out, ")dnl\n"); } - fprintf (out, "[%*s%s]])\n\n", + fprintf (out, "[%*s%s]],\n[[", rules[r].action_loc.start.column - 1, "", rules[r].action); + rule_output (&rules[r], out); + fprintf (out, "]])\n\n"); } fputs ("])\n\n", out); } diff --git a/src/parse-gram.c b/src/parse-gram.c index ad6045eb..be3cbe81 100644 --- a/src/parse-gram.c +++ b/src/parse-gram.c @@ -1,4 +1,4 @@ -/* A Bison parser, made by GNU Bison 3.6.2.71-273f. */ +/* A Bison parser, made by GNU Bison 3.6.3.74-5ca2. */ /* Bison implementation for Yacc-like parsers in C @@ -49,7 +49,7 @@ #define YYBISON 1 /* Bison version. */ -#define YYBISON_VERSION "3.6.2.71-273f" +#define YYBISON_VERSION "3.6.3.74-5ca2" /* Skeleton name. */ #define YYSKELETON_NAME "yacc.c" @@ -2055,7 +2055,7 @@ yyreduce: int yychar_backup = yychar; switch (yyn) { - case 6: + case 6: /* prologue_declaration: "%{...%}" */ { muscle_code_grow (union_seen ? "post_prologue" : "pre_prologue", translate_code ((yyvsp[0].PROLOGUE), (yylsp[0]), true), (yylsp[0])); @@ -2063,131 +2063,131 @@ yyreduce: } break; - case 7: + case 7: /* prologue_declaration: "%<flag>" */ { muscle_percent_define_ensure ((yyvsp[0].PERCENT_FLAG), (yylsp[0]), true); } break; - case 8: + case 8: /* prologue_declaration: "%define" variable value */ { muscle_percent_define_insert ((yyvsp[-1].variable), (yyloc), (yyvsp[0].value).kind, (yyvsp[0].value).chars, MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE); } break; - case 9: + case 9: /* prologue_declaration: "%defines" */ { defines_flag = true; } break; - case 10: + case 10: /* prologue_declaration: "%defines" "string" */ { defines_flag = true; spec_header_file = xstrdup ((yyvsp[0].STRING)); } break; - case 11: + case 11: /* prologue_declaration: "%error-verbose" */ { handle_error_verbose (&(yyloc), (yyvsp[0].PERCENT_ERROR_VERBOSE)); } break; - case 12: + case 12: /* prologue_declaration: "%expect" "integer literal" */ { expected_sr_conflicts = (yyvsp[0].INT); } break; - case 13: + case 13: /* prologue_declaration: "%expect-rr" "integer literal" */ { expected_rr_conflicts = (yyvsp[0].INT); } break; - case 14: + case 14: /* prologue_declaration: "%file-prefix" "string" */ { handle_file_prefix (&(yyloc), &(yylsp[-1]), (yyvsp[-1].PERCENT_FILE_PREFIX), (yyvsp[0].STRING)); } break; - case 15: + case 15: /* prologue_declaration: "%glr-parser" */ { nondeterministic_parser = true; glr_parser = true; } break; - case 16: + case 16: /* prologue_declaration: "%initial-action" "{...}" */ { muscle_code_grow ("initial_action", translate_code ((yyvsp[0].BRACED_CODE), (yylsp[0]), false), (yylsp[0])); code_scanner_last_string_free (); } break; - case 17: + case 17: /* prologue_declaration: "%language" "string" */ { language_argmatch ((yyvsp[0].STRING), grammar_prio, (yylsp[-1])); } break; - case 18: + case 18: /* prologue_declaration: "%name-prefix" "string" */ { handle_name_prefix (&(yyloc), (yyvsp[-1].PERCENT_NAME_PREFIX), (yyvsp[0].STRING)); } break; - case 19: + case 19: /* prologue_declaration: "%no-lines" */ { no_lines_flag = true; } break; - case 20: + case 20: /* prologue_declaration: "%nondeterministic-parser" */ { nondeterministic_parser = true; } break; - case 21: + case 21: /* prologue_declaration: "%output" "string" */ { spec_outfile = (yyvsp[0].STRING); } break; - case 22: + case 22: /* $@1: %empty */ { current_param = (yyvsp[0].PERCENT_PARAM); } break; - case 23: + case 23: /* prologue_declaration: "%param" $@1 params */ { current_param = param_none; } break; - case 24: + case 24: /* prologue_declaration: "%pure-parser" */ { handle_pure_parser (&(yyloc), (yyvsp[0].PERCENT_PURE_PARSER)); } break; - case 25: + case 25: /* prologue_declaration: "%require" "string" */ { handle_require (&(yylsp[0]), (yyvsp[0].STRING)); } break; - case 26: + case 26: /* prologue_declaration: "%skeleton" "string" */ { handle_skeleton (&(yylsp[0]), (yyvsp[0].STRING)); } break; - case 27: + case 27: /* prologue_declaration: "%token-table" */ { token_table_flag = true; } break; - case 28: + case 28: /* prologue_declaration: "%verbose" */ { report_flag |= report_states; } break; - case 29: + case 29: /* prologue_declaration: "%yacc" */ { handle_yacc (&(yyloc)); } break; - case 30: + case 30: /* prologue_declaration: error ";" */ { current_class = unknown_sym; yyerrok; } break; - case 32: + case 32: /* params: params "{...}" */ { add_param (current_param, (yyvsp[0].BRACED_CODE), (yylsp[0])); } break; - case 33: + case 33: /* params: "{...}" */ { add_param (current_param, (yyvsp[0].BRACED_CODE), (yylsp[0])); } break; - case 35: + case 35: /* grammar_declaration: "%start" symbol */ { grammar_start_symbol_set ((yyvsp[0].symbol), (yylsp[0])); } break; - case 36: + case 36: /* grammar_declaration: code_props_type "{...}" generic_symlist */ { code_props code; code_props_symbol_action_init (&code, (yyvsp[-1].BRACED_CODE), (yylsp[-1])); @@ -2200,19 +2200,19 @@ yyreduce: } break; - case 37: + case 37: /* grammar_declaration: "%default-prec" */ { default_prec = true; } break; - case 38: + case 38: /* grammar_declaration: "%no-default-prec" */ { default_prec = false; } break; - case 39: + case 39: /* grammar_declaration: "%code" "{...}" */ { /* Do not invoke muscle_percent_code_grow here since it invokes muscle_user_name_list_grow. */ @@ -2222,32 +2222,32 @@ yyreduce: } break; - case 40: + case 40: /* grammar_declaration: "%code" "identifier" "{...}" */ { muscle_percent_code_grow ((yyvsp[-1].ID), (yylsp[-1]), translate_code_braceless ((yyvsp[0].BRACED_CODE), (yylsp[0])), (yylsp[0])); code_scanner_last_string_free (); } break; - case 41: + case 41: /* code_props_type: "%destructor" */ { (yyval.code_props_type) = destructor; } break; - case 42: + case 42: /* code_props_type: "%printer" */ { (yyval.code_props_type) = printer; } break; - case 43: + case 43: /* union_name: %empty */ {} break; - case 44: + case 44: /* union_name: "identifier" */ { muscle_percent_define_insert ("api.value.union.name", (yylsp[0]), muscle_keyword, (yyvsp[0].ID), MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE); } break; - case 45: + case 45: /* grammar_declaration: "%union" union_name "{...}" */ { union_seen = true; muscle_code_grow ("union_members", translate_code_braceless ((yyvsp[0].BRACED_CODE), (yylsp[0])), (yylsp[0])); @@ -2255,35 +2255,35 @@ yyreduce: } break; - case 46: + case 46: /* $@2: %empty */ { current_class = nterm_sym; } break; - case 47: + case 47: /* symbol_declaration: "%nterm" $@2 nterm_decls */ { current_class = unknown_sym; symbol_list_free ((yyvsp[0].nterm_decls)); } break; - case 48: + case 48: /* $@3: %empty */ { current_class = token_sym; } break; - case 49: + case 49: /* symbol_declaration: "%token" $@3 token_decls */ { current_class = unknown_sym; symbol_list_free ((yyvsp[0].token_decls)); } break; - case 50: + case 50: /* symbol_declaration: "%type" symbol_decls */ { symbol_list_free ((yyvsp[0].symbol_decls)); } break; - case 51: + case 51: /* symbol_declaration: precedence_declarator token_decls_for_prec */ { ++current_prec; for (symbol_list *list = (yyvsp[0].token_decls_for_prec); list; list = list->next) @@ -2292,77 +2292,77 @@ yyreduce: } break; - case 52: + case 52: /* precedence_declarator: "%left" */ { (yyval.precedence_declarator) = left_assoc; } break; - case 53: + case 53: /* precedence_declarator: "%right" */ { (yyval.precedence_declarator) = right_assoc; } break; - case 54: + case 54: /* precedence_declarator: "%nonassoc" */ { (yyval.precedence_declarator) = non_assoc; } break; - case 55: + case 55: /* precedence_declarator: "%precedence" */ { (yyval.precedence_declarator) = precedence_assoc; } break; - case 56: + case 56: /* tag.opt: %empty */ { (yyval.yykind_74) = NULL; } break; - case 57: + case 57: /* tag.opt: "<tag>" */ { (yyval.yykind_74) = (yyvsp[0].TAG); } break; - case 59: + case 59: /* generic_symlist: generic_symlist generic_symlist_item */ { (yyval.generic_symlist) = symbol_list_append ((yyvsp[-1].generic_symlist), (yyvsp[0].generic_symlist_item)); } break; - case 60: + case 60: /* generic_symlist_item: symbol */ { (yyval.generic_symlist_item) = symbol_list_sym_new ((yyvsp[0].symbol), (yylsp[0])); } break; - case 61: + case 61: /* generic_symlist_item: tag */ { (yyval.generic_symlist_item) = symbol_list_type_new ((yyvsp[0].tag), (yylsp[0])); } break; - case 63: + case 63: /* tag: "<*>" */ { (yyval.tag) = uniqstr_new ("*"); } break; - case 64: + case 64: /* tag: "<>" */ { (yyval.tag) = uniqstr_new (""); } break; - case 66: + case 66: /* token_decls: token_decl.1 */ { (yyval.token_decls) = (yyvsp[0].yykind_80); } break; - case 67: + case 67: /* token_decls: "<tag>" token_decl.1 */ { (yyval.token_decls) = symbol_list_type_set ((yyvsp[0].yykind_80), (yyvsp[-1].TAG), (yylsp[-1])); } break; - case 68: + case 68: /* token_decls: token_decls "<tag>" token_decl.1 */ { (yyval.token_decls) = symbol_list_append ((yyvsp[-2].token_decls), symbol_list_type_set ((yyvsp[0].yykind_80), (yyvsp[-1].TAG), (yylsp[-1]))); } break; - case 69: + case 69: /* token_decl.1: token_decl */ { (yyval.yykind_80) = symbol_list_sym_new ((yyvsp[0].token_decl), (yylsp[0])); } break; - case 70: + case 70: /* token_decl.1: token_decl.1 token_decl */ { (yyval.yykind_80) = symbol_list_append ((yyvsp[-1].yykind_80), symbol_list_sym_new ((yyvsp[0].token_decl), (yylsp[0]))); } break; - case 71: + case 71: /* token_decl: id int.opt alias */ { (yyval.token_decl) = (yyvsp[-2].id); symbol_class_set ((yyvsp[-2].id), current_class, (yylsp[-2]), true); @@ -2373,19 +2373,19 @@ yyreduce: } break; - case 72: + case 72: /* int.opt: %empty */ { (yyval.yykind_82) = -1; } break; - case 74: + case 74: /* alias: %empty */ { (yyval.alias) = NULL; } break; - case 75: + case 75: /* alias: string_as_id */ { (yyval.alias) = (yyvsp[0].string_as_id); } break; - case 76: + case 76: /* alias: "translatable string" */ { (yyval.alias) = symbol_get (quotearg_style (c_quoting_style, (yyvsp[0].TSTRING)), (yylsp[0])); symbol_class_set ((yyval.alias), token_sym, (yylsp[0]), false); @@ -2393,33 +2393,33 @@ yyreduce: } break; - case 77: + case 77: /* token_decls_for_prec: token_decl_for_prec.1 */ { (yyval.token_decls_for_prec) = (yyvsp[0].yykind_85); } break; - case 78: + case 78: /* token_decls_for_prec: "<tag>" token_decl_for_prec.1 */ { (yyval.token_decls_for_prec) = symbol_list_type_set ((yyvsp[0].yykind_85), (yyvsp[-1].TAG), (yylsp[-1])); } break; - case 79: + case 79: /* token_decls_for_prec: token_decls_for_prec "<tag>" token_decl_for_prec.1 */ { (yyval.token_decls_for_prec) = symbol_list_append ((yyvsp[-2].token_decls_for_prec), symbol_list_type_set ((yyvsp[0].yykind_85), (yyvsp[-1].TAG), (yylsp[-1]))); } break; - case 80: + case 80: /* token_decl_for_prec.1: token_decl_for_prec */ { (yyval.yykind_85) = symbol_list_sym_new ((yyvsp[0].token_decl_for_prec), (yylsp[0])); } break; - case 81: + case 81: /* token_decl_for_prec.1: token_decl_for_prec.1 token_decl_for_prec */ { (yyval.yykind_85) = symbol_list_append ((yyvsp[-1].yykind_85), symbol_list_sym_new ((yyvsp[0].token_decl_for_prec), (yylsp[0]))); } break; - case 82: + case 82: /* token_decl_for_prec: id int.opt */ { (yyval.token_decl_for_prec) = (yyvsp[-1].id); symbol_class_set ((yyvsp[-1].id), token_sym, (yylsp[-1]), false); @@ -2428,133 +2428,133 @@ yyreduce: } break; - case 84: + case 84: /* symbol_decls: symbol_decl.1 */ { (yyval.symbol_decls) = (yyvsp[0].yykind_88); } break; - case 85: + case 85: /* symbol_decls: "<tag>" symbol_decl.1 */ { (yyval.symbol_decls) = symbol_list_type_set ((yyvsp[0].yykind_88), (yyvsp[-1].TAG), (yylsp[-1])); } break; - case 86: + case 86: /* symbol_decls: symbol_decls "<tag>" symbol_decl.1 */ { (yyval.symbol_decls) = symbol_list_append ((yyvsp[-2].symbol_decls), symbol_list_type_set ((yyvsp[0].yykind_88), (yyvsp[-1].TAG), (yylsp[-1]))); } break; - case 87: + case 87: /* symbol_decl.1: symbol */ { symbol_class_set ((yyvsp[0].symbol), pct_type_sym, (yylsp[0]), false); (yyval.yykind_88) = symbol_list_sym_new ((yyvsp[0].symbol), (yylsp[0])); } break; - case 88: + case 88: /* symbol_decl.1: symbol_decl.1 symbol */ { symbol_class_set ((yyvsp[0].symbol), pct_type_sym, (yylsp[0]), false); (yyval.yykind_88) = symbol_list_append ((yyvsp[-1].yykind_88), symbol_list_sym_new ((yyvsp[0].symbol), (yylsp[0]))); } break; - case 93: + case 93: /* rules_or_grammar_declaration: error ";" */ { yyerrok; } break; - case 94: + case 94: /* $@4: %empty */ { current_lhs ((yyvsp[-1].id_colon), (yylsp[-1]), (yyvsp[0].yykind_95)); } break; - case 95: + case 95: /* rules: id_colon named_ref.opt $@4 ":" rhses.1 */ { /* Free the current lhs. */ current_lhs (0, (yylsp[-4]), 0); } break; - case 96: + case 96: /* rhses.1: rhs */ { grammar_current_rule_end ((yylsp[0])); } break; - case 97: + case 97: /* rhses.1: rhses.1 "|" rhs */ { grammar_current_rule_end ((yylsp[0])); } break; - case 99: + case 99: /* rhs: %empty */ { grammar_current_rule_begin (current_lhs_symbol, current_lhs_loc, current_lhs_named_ref); } break; - case 100: + case 100: /* rhs: rhs symbol named_ref.opt */ { grammar_current_rule_symbol_append ((yyvsp[-1].symbol), (yylsp[-1]), (yyvsp[0].yykind_95)); } break; - case 101: + case 101: /* rhs: rhs tag.opt "{...}" named_ref.opt */ { grammar_current_rule_action_append ((yyvsp[-1].BRACED_CODE), (yylsp[-1]), (yyvsp[0].yykind_95), (yyvsp[-2].yykind_74)); } break; - case 102: + case 102: /* rhs: rhs "%?{...}" */ { grammar_current_rule_predicate_append ((yyvsp[0].BRACED_PREDICATE), (yylsp[0])); } break; - case 103: + case 103: /* rhs: rhs "%empty" */ { grammar_current_rule_empty_set ((yylsp[0])); } break; - case 104: + case 104: /* rhs: rhs "%prec" symbol */ { grammar_current_rule_prec_set ((yyvsp[0].symbol), (yylsp[0])); } break; - case 105: + case 105: /* rhs: rhs "%dprec" "integer literal" */ { grammar_current_rule_dprec_set ((yyvsp[0].INT), (yylsp[0])); } break; - case 106: + case 106: /* rhs: rhs "%merge" "<tag>" */ { grammar_current_rule_merge_set ((yyvsp[0].TAG), (yylsp[0])); } break; - case 107: + case 107: /* rhs: rhs "%expect" "integer literal" */ { grammar_current_rule_expect_sr ((yyvsp[0].INT), (yylsp[0])); } break; - case 108: + case 108: /* rhs: rhs "%expect-rr" "integer literal" */ { grammar_current_rule_expect_rr ((yyvsp[0].INT), (yylsp[0])); } break; - case 109: + case 109: /* named_ref.opt: %empty */ { (yyval.yykind_95) = NULL; } break; - case 110: + case 110: /* named_ref.opt: "[identifier]" */ { (yyval.yykind_95) = named_ref_new ((yyvsp[0].BRACKETED_ID), (yylsp[0])); } break; - case 112: + case 112: /* value: %empty */ { (yyval.value).kind = muscle_keyword; (yyval.value).chars = ""; } break; - case 113: + case 113: /* value: "identifier" */ { (yyval.value).kind = muscle_keyword; (yyval.value).chars = (yyvsp[0].ID); } break; - case 114: + case 114: /* value: "string" */ { (yyval.value).kind = muscle_string; (yyval.value).chars = (yyvsp[0].STRING); } break; - case 115: + case 115: /* value: "{...}" */ { (yyval.value).kind = muscle_code; (yyval.value).chars = strip_braces ((yyvsp[0].BRACED_CODE)); } break; - case 116: + case 116: /* id: "identifier" */ { (yyval.id) = symbol_from_uniqstr ((yyvsp[0].ID), (yylsp[0])); } break; - case 117: + case 117: /* id: "character literal" */ { const char *var = "api.token.raw"; if (current_class == nterm_sym) @@ -2577,18 +2577,18 @@ yyreduce: } break; - case 118: + case 118: /* id_colon: "identifier:" */ { (yyval.id_colon) = symbol_from_uniqstr ((yyvsp[0].ID_COLON), (yylsp[0])); } break; - case 121: + case 121: /* string_as_id: "string" */ { (yyval.string_as_id) = symbol_get (quotearg_style (c_quoting_style, (yyvsp[0].STRING)), (yylsp[0])); symbol_class_set ((yyval.string_as_id), token_sym, (yylsp[0]), false); } break; - case 123: + case 123: /* epilogue.opt: "%%" "epilogue" */ { muscle_code_grow ("epilogue", translate_code ((yyvsp[0].EPILOGUE), (yylsp[0]), true), (yylsp[0])); code_scanner_last_string_free (); diff --git a/src/parse-gram.h b/src/parse-gram.h index f66ffbcf..2ce793f5 100644 --- a/src/parse-gram.h +++ b/src/parse-gram.h @@ -1,4 +1,4 @@ -/* A Bison parser, made by GNU Bison 3.6.2.71-273f. */ +/* A Bison parser, made by GNU Bison 3.6.3.74-5ca2. */ /* Bison interface for Yacc-like parsers in C