set.java

23种设计模式JAVA实现,很好很有用的东西.

package inter;
import lexer.*; import symbols.*;

public class Set extends Stmt {

   public Id id; public Expr expr;

   public Set(Id i, Expr x) {
      id = i; expr = x;
      if ( check(id.type, expr.type) == null ) error("type error");
   }

   public Type check(Type p1, Type p2) {
      if ( Type.numeric(p1) && Type.numeric(p2) ) return p2;
      else if ( p1 == Type.Bool && p2 == Type.Bool ) return p2;
      else return null;
   }

   public void gen(int b, int a) {
      emit( id.toString() + " = " + expr.gen().toString() );
   }
}