public Foreach(string name,Sentence sentence,Expression expr,CodeData data)
 {
     this.name = name;
     this.sentence = sentence;
     this.expr = expr;
     this.data = data;
 }
 public YieldReturn(Expression expr,CodeData data)
 {
     this.data = data;
     this.expr = expr;
 }
 public Expr(Expression expr,CodeData data)
 {
     this.data = data;
     this.expr = expr;
 }
 public Global(string name,Expression expr,CodeData data)
 {
     this.data = data;
     this.name = name;
     this.expr = expr;
 }
 public While(Expression cond,Sentence source,CodeData data)
 {
     this.data = data;
     this.cond = cond;
     this.source = source;
 }
 public For(Sentence source,string name,Expression first,Expression last,Expression step,CodeData data)
 {
     this.data = data;
     this.source = source;
     this.name = name;
     this.first = first;
     this.last = last;
     this.step = step;
 }