[Lex&Yacc] C언어를 기반으로한 Lex_Yacc 공학계산기...

calc_lex.l

 /* DEFINITION SECTION */

 

%{

#include "calc_yacc.h"

#include <math.h>

extern double yylval;

%}

WHITE_SPACE [ \t]+

END_MARKER "$"

DOUBLE_VAL ([0-9]+|([0-9]*\.[0-9]+)([eE][-+]?[0-9]+)?) 

%%

 /* RULE SECTION */

 

{DOUBLE_VAL} { yylval = atof(yytext); return NUMBER; }

"+" { return PLUS; }

"-" { return MINUS; } 

"*" { return MULT; }

"/" { return DIV; }

"abs" { return ABS; }

"sqrt" { return SQRT; }

"log" { return LOG; }

"!" { return FAC; }

"^" { return POW; }

"sin" { return SIN; }

"cos" { return COS; }

"tan" { return TAN; }

"mod" { return MOD; }

"div" { return NAMO; }   

"(" { return OPEN; }

")" { return CLOSE; }

"round" { return ROUND; }

"ceil" { return CEIL; }

"fix" { return FIX; } 

"floor" { return FLOOR; }

{WHITE_SPACE} { ; }

{END_MARKER} { return 0;}

\n { return '\n';}

. { return(yytext[0]);}

%% 

------------------------------------------------------------------------------------------
calc_yacc.y

 /* Definition Section */

 

%{

#include <stdio.h>  

#include <math.h>

#define YYSTYPE double            

double absfunction(double i){

if ( i < 0 ) return -i;

else return i;

}

int round(double i){

double a = i;

double b = (int) i;        

if ( i >= 0 ){

if ( a - b >= 0.5 ){

return (int)i + 1;

}else{

return (int) i;

}

}else{

if ( a - b < -0.5 ){

return (int)i -1;

}else{

return (int)i;

}

}

}

int isinteger(double i){

double a = i;

double b = (int) i;

if ( a - b == 0 ) return 1;

else return 0;

}

 

int fac(double num){

int i;

int result = 1;

for ( i = 1 ; i <= num ; i++ ){

result *= i;

}

return result;

}

%}

%token NUMBER

%left PLUS, MINUS

%left MULT, DIV, MOD, NAMO

%left ABS, SQRT, LOG, SIN, COS, TAN

%right POW   

%left FAC

%left ROUND, CEIL, FIX, FLOOR

%left OPEN, CLOSE

%%

 /* Rule Section */

statement :statement expr '\n' { printf(" = %g\n", $2); }

|statement '\n' { printf("Insert Formula.\n"); }

|error '\n' { yyerror("Error! Review Formula!\n"); yyerrok(); }

|{}

;

expr : expr PLUS term { $$ = $1 + $3; }

| expr MINUS term { $$ = $1 - $3; }

     | term

;

term : term MULT oper { $$ = $1 * $3; }

| term DIV oper { 

if ( $3 == 0 ) yyerror("Divide by Zero(0)\n");

else $$ = $1 / $3; 

}

| term MOD oper { 

if ( $3 == 0 ) yyerror("Divide by Zero(0)\n");

else $$ = (int)$1 % (int)$3;

}     

| term NAMO oper {

if ( $3 == 0 ) yyerror("Divide by Zero(0)\n");

else $$ = (int)($1 / $3);

}

| oper

;

oper : ABS ants { $$ = absfunction($3); }

| SQRT ants { $$ = sqrt($3); }

| LOG ants{

if ( $3 <= 0 ) yyerror("Log(n), n is upper than Zero(0)\n");

else $$ = log($3);

}

| SIN ants { $$ = sin($3); }

| COS ants { $$ = cos($3); }

| TAN ants { $$ = tan($3); }

| ants

;

ants : ruds POW ants { $$ = pow($1,$3); }

| ruds FAC {

if ( $1 <= 0 ) yyerror("Factorial(n), n is upper than Zero(0)\n");  

else if ( isinteger($1) == 0 ) yyerror("Factorial(n), n must be inserted integer\n");  

else $$ = fac($1);

}

| ruds

;

ruds : ROUND upup { $$ = round($3); }

| CEIL upup { 

if ( $3 <= 0 ) yyerror("Ceil(n), n is upper than zero(0)\n");

else $$ = ceil($3);

}

| FIX upup { $$ = (int)$3; }

| FLOOR upup { 

if ( $3 >= 0 ) yyerror("Floor(n), n is downer than zero(0)\n");

else $$ = floor($3);

}   

| upup

;

upup : OPEN expr CLOSE { $$ = $2; }

| MINUS expr { $$ = -$2; }

     | NUMBER { $$ = $1; }

;

%% 
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