Is such HTML template possible?

[alexeypetrushin]

Would be better to write this
    
    
    proc toggle_all(e: ChangeEvent): void =
        self.items.each((item: TodoItem) => (item.completed = self.toggle_all))
    
    
    Run

as this
    
    
    proc toggle_all(e: ChangeEvent): void =
      self.items.each((item: TodoItem) => (item.completed = self.toggle_all))
    
    proc toggle_all(e: ChangeEvent): void =
      self.items.each((item) => item.completed = self.toggle_all)
    
    
    Run

Or even as this (I know about `it` macros, it can't do that, as it should work 
for every single argument proc)
    
    
    proc toggle_all(e: ChangeEvent): void =
      self.items.each &.completed = self.toggle_all
    
    
    Run