Dart lex/yacc?

calc.dartl

%{
  import 'calc.darty.dart';
%}
%%
[ \t\n]   ;
[0-9]+    { yyval = int.parse(yytext); return T_NUMBER; }
\(        { return T_LPAREN; }
\)        { return T_RPAREN; }
\*        { return T_TIMES; }
\/        { return T_SLASH; }
\%        { return T_PERCENT; }
\+        { return T_PLUS; }
\-        { return T_MINUS; }
%%

calc.darty

%{
  import 'dart:io';
  import 'calc.dartl.dart';
%}

%token<int> T_NUMBER "number"
%token<int> T_TIMES "*"
%token<int> T_SLASH "/"
%token<int> T_PERCENT "%"
%token<int> T_PLUS "+"
%token<int> T_MINUS "-"

%type<int> expr

%%

expr
  "number"        { $$ = yylval; }
  | expr "*" expr { $$ = $1 * $2; }
  | expr "/" expr { $$ = $1 * $2; }  
  | expr "%" expr { $$ = $1 * $2; }  
  | expr "+" expr { $$ = $1 * $2; }  
  | expr "-" expr { $$ = $1 * $2; }  
  | "(" expr ")"  { $$ = $2; }
  
%%
void yyerror(String msg) {
  stderr.writeln(msg);
  exit(1);
}

void main() {
  while(true) {
    String line;
    stdout.write("calc) ");
    line = stdin.readLineSync();
    yyparse(line);
    stdout.writeln(yylval);
  }
}