nepc.y.bak

一个小计算器的实现(编译原理),用Lex和bison

%{
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include "nepc.h"


%}

%union{int iValue;double fValue;char *pStr;long *nPtr;
int type_int;
float type_float;
double type_double;
long type_long;
};
%token <type_int> TYPE_INT
%token <type_float> TYPE_FLOAT
%token <type_double> TYPE_DOUBLE
%token <type_long> TYPE_LONG
%token <pStr> TYPE_STRING
%token <iValue> TYPE_STRUCT


%token <iValue> INTEGER
%token <fValue> FLOAT
%token <pStr> VARIABLE  
%token <pStr> STRING
%token <iValue> ACOS ASIN ATAN CEIL COS COSH EXP FABS FLOOR 
%token <iValue> LOG LOG10 POW10 SIN SINH SQRT TAN TANH

%type <nPtr> stmt expr  /*function*/

%token EXIT ERASE CLEAR LIST HELP DEC HEX OCT
%token WHILE IF PRINT FOR

%nonassoc IFX
%nonassoc ELSE

%left OR
%left AND
%left GE LE EQ NE '>' '<'
%left '+' '-'
%left '*' '/' '%'
%left PP SS
%nonassoc UMINUS


%%
program:
    init parsed EXIT        {  }
  ;
init: /* NULL*/             {  printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>begin !");} 
  ;
parsed:
    parsed stmt             {
				sentenceArray[sentenceArrayLen]=$2;
                                sentenceArrayLen++;
				 
			    }
 /* | parsed error separator  { yyerrok; WAITINPUT;} comment by chenbp*/
  | /* NULL */
  ;

stmt:
    separator               { $$ = opr(';', 2, NULL, NULL);  }

  | PRINT expr separator    { $$ = opr(PRINT, 1, $2); }
  | VARIABLE '=' expr separator     {
				if(NULL==var($1,G_level,G_line))
					{
						YYABORT;
					}
				$$ = (($3 == NULL)?NULL:(opr('=', 2, var($1,G_level,G_line), $3)));
					    printf("level:%d\n",G_level);
				    }
  | type_define  VARIABLE '=' expr separator  
				{
					if($4 == NULL)
					{
						$$=NULL;
						printf("null  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n");
					}
					else
					{
						nodeType *p=opr('=', 2, var($2,G_level,G_line), $4);
						if(p==NULL)
						{
							printf("null 22  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n");
						}
						$$=p;

						printf("install the vaiable level:%d\t line:%d\n",G_level,G_line);
					}
			        }
type_define:
	TYPE_INT
	|TYPE_FLOAT
	|TYPE_DOUBLE
	|TYPE_LONG
	|TYPE_STRING
;

separator:
    ';'
  ;
expr:
    INTEGER                 { $$ = con_int($1); }
  | FLOAT                   { $$ = con_flt($1); }
  | STRING                  { $$ = con_str($1); }
  | VARIABLE                { $$ = var($1,G_level,G_line);if($$==NULL)YYABORT; }
  | '-' expr %prec UMINUS   { $$ = opr(UMINUS, 1, $2); }

  | expr '+' expr           { $$ = opr('+', 2, $1, $3); }
  | expr '-' expr           { $$ = opr('-', 2, $1, $3); }
  | expr '*' expr           { $$ = opr('*', 2, $1, $3); }
  | expr '/' expr           { $$ = opr('/', 2, $1, $3); }
  | expr '<' expr           { $$ = opr('<', 2, $1, $3); }
  | expr '>' expr           { $$ = opr('>', 2, $1, $3); }
  | expr '%' expr           { $$ = opr('%', 2, $1, $3); }
  | expr AND expr           { $$ = opr(AND, 2, $1, $3); }
  | expr OR expr            { $$ = opr(OR, 2, $1, $3); }
  | expr GE expr            { $$ = opr(GE, 2, $1, $3); }
  | expr LE expr            { $$ = opr(LE, 2, $1, $3); }
  | expr NE expr            { $$ = opr(NE, 2, $1, $3); }
  | expr EQ expr            { $$ = opr(EQ, 2, $1, $3); }
  | '(' expr ')'            { $$ = $2; }

%%