AoC day 18 (yacc file)

%{
#include <stdio.h>
#include <stdlib.h>

#define YYSTYPE long long

long long Result = 0;
%}

%token INT EOL

%left '+' '*'

%start File

%%

File: | File Line

Line: Expression EOL                { Result += $1; }

Expression:
    INT                             { $$ = $1;      }
    | '(' Expression ')'            { $$ = $2;      }
    | Expression '+' Expression     { $$ = $1 + $3; }
    | Expression '*' Expression     { $$ = $1 * $3; }
;

%%

int yyerror( char *s ) {
    printf( "Error: %s\n", s );
}

int main() {
    yyparse();
    printf( "%lld\n", Result );
}