anchor.diff:    Most list commands eat keys:
       sort, reverse, etc
     
  -
  -DECISIONS TO BE MADE
  -  In order of importance... write about these when you make them.
  +  The {logic is} command doesn't coerce internally
  +    {"2" | is in (2) | then :true else :false}
  +      true
  +  
  +  Two problems here with peek/poke
  +  1. you shouldn't have to preload with x:1 (BUG)
  +  2. setting a subitem returns the full spacevar, not just the subitem value (BUG)
  +    {* (:x 1) | $>hash}
  +      {"x":1}
  +
  +    {:ash | $>hash.{"two"}} {$hash}
  +      ash {"x":1,"two":"ash"}
  +
  +    {:ash | $>hash.{"two"}.monkey.flu} {$hash}
  +      ash {"x":1,"two":{"monkey":{"flu":"ash"}}}
  +
  +    {:ash | $>hash.{"two"}.monkey.{(:x :y :z)}.flu} {$hash}
  +      ash {"x":1,"two":{"monkey":{"x":{"flu":"ash"},"y":{"flu":"ash"},"z":{"flu":"ash"}}}}
  +
  +  Double pipe leaks values if next segment is an error
  +    {123 | >_foo || __foo}
  +  
  +  Tail position pipeline vars flake out [probably requires placeholder segtype]
  +    {2 | >two | "" | _two}
  +      2
  +
  +
  +<h2>DECISIONS TO BE MADE</h2>
  +  In approximate order of importance... write about these when you make them.
   
     Blocks aren't strings. How do we distinguish them? How do they work? When are they executed? What's their syntax? Can we make string manipulation easier? Can we keep string generation just as easy? List all cases.
   
  
positive.code: 
    (Blocks with the same name can't be nested. That would just be weird.)
  
  Quick 3: Commands in lists
  
      A list can have commands in it
        {({string split value "shantung weft repp slub" on " "} 1 2 4 8)}
          [["shantung","weft","repp","slub"],1,2,4,8]
  
  Quick 4: Quotes in braces
  
      If the nested quotes are in braces, you don't need to use a block:
        {string split on " " value {("inside" "here") | string join on " "}}
  
negative.code:       {"{("Much" "nesting") | string join on " "} is divinest sense" | run | split on " " | join on " "}
          Much nesting is divinest sense
  
  
  <h2>In Depth: Scope</h2>
  
    so.... blocks don't have a private scope. there's currently pipeline vars and space vars. pipeline vars are single-assignment and can bleed through blocks (but not into called subblocks). 
    
  