anchor.diff:             :inject-implicit-uniform
              :input-variable-glsl
              :input-variables
  +           :input-variable
  +           :implicit-uniform-variable
              :join-glsl-chunks
              :join-glsl-of-compiled
              :line-loop
  
positive.code:    :*draw-modes*
     :*stage-names*
     :*stage-type-names*
     :*supported-draw-modes*
     :*supported-versions*
     :*valid-contents-symbols*
     ;;
  
negative.code:            :*return-var-name-base*
             :*stage-names*
             :*stage-type-names*
             :*supported-versions*
             :*valid-contents-symbols*
             :%uniform-name
  