yabasic.bison

Linux下VB解释器

function_name: tSYMBOL {function_type=ftNUMBER;current_function=my_strdup(dotify($1,FALSE));$$=my_strdup(dotify($1,FALSE));}
  | tSTRSYM {function_type=ftSTRING;current_function=my_strdup(dotify($1,FALSE));$$=my_strdup(dotify($1,FALSE));}
  ;

export: /* empty */ {exported=FALSE;}
  | tEXPORT {exported=TRUE;}
  | tRUNTIME_CREATED_SUB {exported=FALSE;}
  | tRUNTIME_CREATED_SUB tEXPORT {exported=TRUE;}
  ;

local_list: local_item
  | local_list ',' local_item
  ;

local_item: tSYMBOL {create_makelocal(dotify($1,FALSE),syNUMBER);}
  | tSTRSYM {create_makelocal(dotify($1,FALSE),sySTRING);}
  | tSYMBOL '(' call_list ')' {create_makelocal(dotify($1,FALSE),syARRAY);create_dim(dotify($1,FALSE),'d');}
  | tSTRSYM '(' call_list ')' {create_makelocal(dotify($1,FALSE),syARRAY);create_dim(dotify($1,FALSE),'s');}
  ;
  
static_list: static_item
  | static_list ',' static_item
  ;

static_item: tSYMBOL {create_makestatic(dotify($1,TRUE),syNUMBER);}
  | tSTRSYM {create_makestatic(dotify($1,TRUE),sySTRING);}
  | tSYMBOL '(' call_list ')' {create_makestatic(dotify($1,TRUE),syARRAY);create_dim(dotify($1,TRUE),'D');}
  | tSTRSYM '(' call_list ')' {create_makestatic(dotify($1,TRUE),syARRAY);create_dim(dotify($1,TRUE),'S');}
  ;
  
paramlist: /* empty */
  | paramitem
  | paramlist ',' paramitem
  ;
  
paramitem: tSYMBOL {create_require(stNUMBER);create_makelocal(dotify($1,FALSE),syNUMBER);add_command(cPOPDBLSYM,dotify($1,FALSE));}
  | tSTRSYM {create_require(stSTRING);create_makelocal(dotify($1,FALSE),sySTRING);add_command(cPOPSTRSYM,dotify($1,FALSE));}
  | tSYMBOL '(' ')' {create_require(stNUMBERARRAYREF);create_arraylink(dotify($1,FALSE),stNUMBERARRAYREF);}
  | tSTRSYM '(' ')' {create_require(stSTRINGARRAYREF);create_arraylink(dotify($1,FALSE),stSTRINGARRAYREF);}
  ;

for_loop: tFOR {missing_next++;missing_next_line=yylineno;} tSYMBOL tEQU 
            {pushname(dotify($3,FALSE)); /* will be used by next_symbol to check equality */
	     add_command(cRESETSKIPONCE,NULL);
	     pushgoto();add_command(cCONTINUE_HERE,NULL);create_break_mark(0,1);}
	  expression tTO expression 
	  step_part { /* pushes another expression */
	     add_command(cSKIPONCE,NULL);
	     pushlabel();
	     add_command(cSTARTFOR,NULL);
	     add_command(cPOPDBLSYM,dotify($3,FALSE));
	     poplabel();
	     add_command(cPUSHDBLSYM,dotify($3,FALSE));
	     add_command(cFORINCREMENT,NULL);
	     add_command(cPOPDBLSYM,dotify($3,FALSE));
	     add_command(cPUSHDBLSYM,dotify($3,FALSE));
	     add_command(cFORCHECK,NULL);
	     add_command(cDECIDE,NULL);
             pushlabel();}
          statement_list {
             swap();popgoto();poplabel();}
          next next_symbol {create_break_mark(0,-1);add_command(cBREAK_HERE,NULL);}
  ;

next: tEOPROG {if (missing_next) {sprintf(string,"%d next(s) are missing (last at line %d)",missing_next,missing_next_line);error(ERROR,string);} YYABORT;}
  | tNEXT {missing_next--;}
  ;

step_part: {create_pushdbl(1);} /* can be omitted */
  | tSTEP expression
  ;

next_symbol:  {pop(stSTRING);}/* can be omitted */
  | tSYMBOL {if (strcmp(pop(stSTRING)->pointer,dotify($1,FALSE))) 
             {error(ERROR,"'for' and 'next' do not match"); YYABORT;}
           }
  ;

switch_number_or_string: tSWITCH {push_switch_id();add_command(cPUSH_SWITCH_MARK,NULL);create_break_mark(0,1);
	add_command(cCONTINUE_CORRECTION,NULL);} 
                number_or_string sep_list case_list default tSEND {create_break_mark(-1,0);add_command(cBREAK_HERE,NULL);create_break_mark(0,-1);add_command(cBREAK_HERE,NULL);create_clean_switch_mark(0,FALSE);pop_switch_id();}
  ;

sep_list: tSEP {if ($1>=0) yylineno+=$1;} 
  | sep_list tSEP {if ($2>=0) yylineno+=$2;} 
  ;

number_or_string: expression
  | string_expression
  ;


case_list: /* empty */
  | case_list tCASE {create_break_mark(-1,0);add_command(cBREAK_HERE,NULL);} number_or_string
      {add_command(cSWITCH_COMPARE,NULL);add_command(cDECIDE,NULL);add_command(cMINOR_BREAK,NULL);create_break_mark(1,0);} statement_list {add_command(cNEXT_CASE,NULL);}
  ;


default: /* empty */
  | tDEFAULT tSEP {if ($2>=0) yylineno+=$2; create_break_mark(-1,0);add_command(cBREAK_HERE,NULL);} statement_list
  ;


do_loop: tDO {add_command(cCONTINUE_HERE,NULL);create_break_mark(0,1);missing_loop++;missing_loop_line=yylineno;pushgoto();}
	      statement_list
            loop
  ;


loop: tEOPROG {if (missing_loop) {sprintf(string,"%d loop(s) are missing (last at line %d)",missing_loop,missing_loop_line);error(ERROR,string);} YYABORT;}
  | tLOOP {missing_loop--;popgoto();create_break_mark(0,-1);add_command(cBREAK_HERE,NULL);}
  ;


while_loop: tWHILE {add_command(cCONTINUE_HERE,NULL);create_break_mark(0,1);missing_wend++;missing_wend_line=yylineno;pushgoto()} '(' expression ')'
	      {add_command(cDECIDE,NULL);
	      pushlabel();}
	      statement_list
            wend
  ;	    

wend: tEOPROG {if (missing_wend) {sprintf(string,"%d wend(s) are missing (last at line %d)",missing_wend,missing_wend_line);error(ERROR,string);} YYABORT;}
  | tWEND {missing_wend--;swap();popgoto();poplabel();create_break_mark(0,-1);add_command(cBREAK_HERE,NULL);}
  ;


repeat_loop: tREPEAT {add_command(cCONTINUE_HERE,NULL);create_break_mark(0,1);missing_until++;missing_until_line=yylineno;pushgoto();} 
	       statement_list
	     until
  ;

until: tEOPROG {if (missing_until) {sprintf(string,"%d until(s) are missing (last at line %d)",missing_until,missing_until_line);error(ERROR,string);} YYABORT;}
  | tUNTIL '(' expression ')'
	       {missing_until--;add_command(cDECIDE,NULL);popgoto();create_break_mark(0,-1);add_command(cBREAK_HERE,NULL);}
  ;

if_clause: tIF expression {add_command(cDECIDE,NULL);storelabel();pushlabel();}
           tTHEN {missing_endif++;missing_endif_line=yylineno;} statement_list {swap();matchgoto();swap();poplabel();}
	   elsif_part
           else_part {poplabel();}
           endif
  ;

endif: tEOPROG {if (missing_endif) {sprintf(string,"%d endif(s) are missing (last at line %d)",missing_endif,missing_endif_line);error(ERROR,string);} YYABORT;}
  | tENDIF {missing_endif--;}
  ;

short_if:  tIF expression {fi_pending++;add_command(cDECIDE,NULL);pushlabel();}
	statement_list tENDIF {poplabel();}
  ;

else_part: /* can be omitted */
  | tELSE statement_list
  ;

elsif_part: /* can be omitted */
  | tELSIF expression maybe_then
    	{add_command(cDECIDE,NULL);pushlabel();} 
    statement_list 
	{swap();matchgoto();swap();poplabel();} 
    elsif_part
  ;

maybe_then: /* can be omitted */
  | tTHEN
  ;

inputlist: input
  | input ',' {add_command(cCHKPROMPT,NULL);} inputlist
  ;

input: tSYMBOL {create_myread('d',tileol);add_command(cPOPDBLSYM,dotify($1,FALSE));}
  | tSYMBOL '(' call_list ')' 
    	{create_myread('d',tileol);create_doarray(dotify($1,FALSE),ASSIGNARRAY);}
  | tSTRSYM {create_myread('s',tileol);add_command(cPOPSTRSYM,dotify($1,FALSE));}
  | tSTRSYM '(' call_list ')' 
    	{create_myread('s',tileol);create_doarray(dotify($1,FALSE),ASSIGNSTRINGARRAY);}
  ;

readlist: readitem
  | readlist ',' readitem
  ;

readitem: tSYMBOL {create_readdata('d');add_command(cPOPDBLSYM,dotify($1,FALSE));}
  | tSYMBOL '(' call_list ')' 
    {create_readdata('d');create_doarray(dotify($1,FALSE),ASSIGNARRAY);}
  | tSTRSYM {create_readdata('s');add_command(cPOPSTRSYM,dotify($1,FALSE));}
  | tSTRSYM '(' call_list ')' 
    {create_readdata('s');create_doarray(dotify($1,FALSE),ASSIGNSTRINGARRAY);}
  ;

datalist: tSTRING {create_strdata($1);}
  | const {create_dbldata($1);}
  | datalist ','  tSTRING {create_strdata($3);}
  | datalist ',' const {create_dbldata($3);}
  ;

printlist:  /* possible empty */
  | expression using
  | printlist ',' expression using
  | string_expression {create_print('s');} 
  | printlist ',' string_expression {create_print('s');}
  ;

using: {create_print('d');} /* possible empty */
  | tUSING string_expression {create_print('u');}
  | tUSING '(' string_expression ',' string_expression ')' {create_print('U');}
  ;

inputbody: '#' tSYMBOL {add_command(cPUSHDBLSYM,dotify($2,FALSE));create_pps(cPUSHSTREAM,1);} inputlist {create_pps(cPOPSTREAM,0);}
  | '#' tDIGITS {create_pushdbl(atoi($2));create_pps(cPUSHSTREAM,1);} inputlist {create_pps(cPOPSTREAM,0);}
  | '#' '(' expression ')' {create_pps(cPUSHSTREAM,1);} inputlist {create_pps(cPOPSTREAM,0);}
  | tAT '(' expression ',' expression ')' {add_command(cMOVE,NULL);create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,1);} prompt inputlist {create_pps(cPOPSTREAM,0);}
  | {create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,1);} prompt inputlist {create_pps(cPOPSTREAM,0);}
  ;

prompt: /* empty */ {create_pushstr("?");create_print('s');} 
  | tSTRING {create_pushstr($1);create_print('s');}
  ;

printintro: /* may be empty */ {create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,0);}
  | '#' tSYMBOL {add_command(cPUSHDBLSYM,dotify($2,FALSE));create_pps(cPUSHSTREAM,0);}
  | '#' tDIGITS {create_pushdbl(atoi($2));create_pps(cPUSHSTREAM,0);}
  | '#' '(' expression ')' {create_pps(cPUSHSTREAM,0);}
  | tREVERSE {create_colour(1);create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,0);}
  | tCOLOUR '(' string_expression ')' {create_colour(2);create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,0);}
  | tCOLOUR '(' string_expression ',' string_expression ')' {create_colour(3);create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,0);}
  | tAT '(' expression ',' expression ')' {add_command(cMOVE,NULL);create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,0);}
  | tREVERSE tAT '(' expression ',' expression ')' {add_command(cMOVE,NULL);create_colour(1);create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,0);}
  | tCOLOUR '(' string_expression ')' tAT '(' expression ',' expression ')' {add_command(cMOVE,NULL);create_colour(2);create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,0);}
  | tCOLOUR '(' string_expression ',' string_expression ')' tAT '(' expression ',' expression ')' {add_command(cMOVE,NULL);create_colour(3);create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,0);}
  | tAT '(' expression ',' expression ')' tREVERSE {create_colour(1);create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,0);add_command(cMOVE,NULL);}
  | tAT '(' expression ',' expression ')' tCOLOUR '(' string_expression ')' {create_colour(2);create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,0);add_command(cMOVE,NULL);}
  | tAT '(' expression ',' expression ')' tCOLOUR '(' string_expression ',' string_expression ')' {create_colour(3);create_pushdbl(STDIO_STREAM);create_pps(cPUSHSTREAM,0);add_command(cMOVE,NULL);}
  ;  

hashed_number: '#' expression
  | expression;

goto_list: symbol_or_lineno {create_goto((function_type!=ftNONE)?dotify($1,TRUE):$1);add_command(cFINDNOP,NULL);}
  | goto_list ',' symbol_or_lineno {create_goto((function_type!=ftNONE)?dotify($3,TRUE):$3);add_command(cFINDNOP,NULL);}
  ;

gosub_list: symbol_or_lineno {create_gosub((function_type!=ftNONE)?dotify($1,TRUE):$1);add_command(cFINDNOP,NULL);}
  | gosub_list ',' symbol_or_lineno {create_gosub((function_type!=ftNONE)?dotify($3,TRUE):$3);add_command(cFINDNOP,NULL);}
  ;