Is there any way to peek a channel, but not consume it?

[fyquah]

Is there any way to peek a channel to see if there is data, but not consume it? In RTL, this would correspond to just reading the valid signal, but not assert the ready signal. The specific thing i am trying to do here is consider a fair-ish channel arbiter, where you don't always want to let the first one win.

I imagine this is in-theory simple for codegen, but wonder if this will interact negatively with other optimization passes. The component I have in mind looks like the following bit of pseudocode.

struct State {
  rng_state : u32;
}

proc arbiter {
  input_ch0: chan<u32> in; 
  input_ch1: chan<u32> in; 
  output_ch: chan<u32> out;

  init {
    State { rng_state = 0 } 
  }

  next (state : State) {
     let input_ch0_is_valid = peek_is_valid(input_ch0);
     let input_ch1_is_valid  = peek_is_valid(input_ch1);
     let at_least_one_valid = input_ch0_is_valid || input_ch1_is_valid;
     let chosen =  if input_ch0_is_valid && input_ch1_is_valid { 
         // is both valid, pick one at random
        state.rng_state[0]
      }  else if input_ch1_is_valid {
        1:u1
     }  else {
        0:u1
     };
     let (tok0, input_data_0) = recv_if_true(join(), input_ch0, at_least_one_valid & chosen ==0 , u32:0);    
     let (tok1, input_data_1) = recv_if_true(join(), input_ch1, at_least_one_valid & chosen ==1, u32:0);    
     send_if(join(tok0, tok1), output_ch, at_least_one_valid, if chosen == 1:u1 { input_data_0 } { input_data_1 });

     // update_rng_state is defined somewhere else, not too important how it works exactly.
     State { rng_state = update_rng_state (state) }
  }
}

[proppy]

related #1383