title: Chisel Programming Error
body: <p>I am having a problem in my Chisel code, I tried the following approach </p>
  
  <pre><code>deqReg         := Cat((0 until ports).map(ownReg === Cat(io.configVal(portBits*(_) + 2),io.configVal(portBits*(_)+ 1), io.configVal(portBits*(_)))))
  </code></pre>
  
  <p>but I am getting the following error when running the above code</p>
  
  <pre><code>[error] /home/jayant/Dropbox/FIFO/fifo.scala:24: missing parameter type for expanded function ((x$1) =&gt; portBits.$times(x$1).$plus(2))
  [error]     deqReg         := Cat((0 until ports).map(ownReg === Cat(io.configVal(portBits*(_) + 2),io.configVal(portBits*(_)+ 1), io.configVal(portBits*(_)))))
  [error]                                                                                     ^
  [error] one error found
  [error] (compile:compileIncremental) Compilation failed
  [error] Total time: 2 s, completed 4 Sep, 2015 12:31:40 PM
  </code></pre>
  
  <p>can any one tell what is this error and how to correct it. </p>