hello-lexer: hello.yy.c hello.tab.h
	gcc -o hello-lexer hello.yy.c -ll

	./hello-parser < input/newline

	./hello-parser < input/2

#define YY_USER_ACTION \
    yylloc->first_line = yylloc->last_line; \
    yylloc->first_column = yylloc->last_column; \
    for(int i = 0; yytext[i] != '\0'; i++) { \
        if(yytext[i] == '\n') { \
            yylloc->last_line++; \
            yylloc->last_column = 0; \
        } \
        else { \
            yylloc->last_column++; \
        } \
    }

int open_round_count = 0;
int open_curly_count = 0;
int open_square_count = 0;
int close_round_count = 0;
int close_curly_count = 0;
int close_square_count = 0;

SPACE [ ]

DIGIT [0-9]

%option noyywrap
%option yylineno
%option bison-locations

\[     {
          printf("open square\n");
          open_square_count++;
        }
\]     {
          printf("close square\n");
          close_square_count++;
        }

\( {
  return round_open;
}
\) {
  return round_close;
}
\* {
  return multiply;
}
[0-9] {
  yylval->integer = atoi(yytext);
  return single_digit_integer;
}
[1-9][0-9]+ {
  yylval->integer = atoi(yytext);
  return multi_digit_integer;
}
{SPACE} {
  return space;
}
[^()[:space:]]+ {
  printf("%d:%d - %d:%d invalid: '%s'\n",
         yylloc->first_line,
         yylloc->first_column,
         yylloc->last_line,
         yylloc->last_column,
         yytext);
  return invalid;
}

\{      {
          printf("open curly\n");
          open_curly_count++;
        }
\}      {
          printf("close curly\n");
          close_curly_count++;
        }
\(      {
          printf("open round\n");
          open_round_count++;
        }
\)      {
          printf("close round\n");
          close_round_count++;
        }
[A-Za-z_0-9]+ {       
          printf("token: '%s'\n", yytext);
        }
\n      {
          return EOL;
        }
.       {
          printf("invalid: '%s'\n", yytext); 
        }

int yywrap(){
    printf("yywrap is called!\n");
}

  /* definitions */
  #include <stdio.h>
  int yylex();
  int yyerror(char *);

/* definitions */
#include <stdio.h>
int yylex();
int yyerror(char *);

%token EOL

%locations
%define api.pure
%token eol round_open round_close multiply space
%token single_digit_integer multi_digit_integer invalid

 /* rules */

%type <integer>number
%type <integer>single_digit_integer
%type <integer>multi_digit_integer
%union{
  int integer;
}
 /* rules section below */

input: s;

input: EOL;

s: round_open multiply round_close {
              printf("0\n");
   }
   | round_open multiply space number round_close {
              printf("%d\n", $4);
   }
   | round_open multiply space number space number round_close {
              printf("%d\n", $4 * $6);
   }
;

number:
  single_digit_integer
  | multi_digit_integer
;

  printf("error: %s\n", s);

  printf("%s\n", s);