anchor.diff:  
       {1 | else "{fff fff}" | add 1}
         2
  -    {0 | else "{9}" | add 1}
  -      10
   
       {if :true then :awesome}
         awesome
  
positive.code:   {( 0 1 "" "1" "x" "[]" () (1) (() ()) ) | add 0}
      [0,1,0,1,0,0,0,0,0]
  
    {( 0 1 "" "1" "x" "[]" () (1) (() ()) ) | map block "{__ | then 1 else 0}"}
      [0,1,0,1,1,1,0,1,1]
    
    {( 0 1 "" "1" "x" "[]" () (1) (() ()) ) | map block "{__ | string lowercase}"}
  
negative.code:     Tail position pipeline vars flake out [probably requires placeholder segtype]
        {2 | >two | "" | _two}
          2
  
      Aliases with pipes in them bork as second segment in lambdas, because the pipevar segtype munger doesn't properly replace the prevkey with __in. 
      {( 0 1 "" "1" "x" "[]" () (1) (() ()) ) | map block "{__ | then 1 else 0}"}
        [0,1,0,1,1,1,0,1,1]