anchor.diff:  base_expr -> list_string : build_list_string('$1').
   base_expr -> bit_string : '$1'.
   base_expr -> '&' : { '&', [{line,?line('$1')}], ?exprs('$1') }.
  -base_expr -> '...' : { ?id('$1'), [{line,?line('$1')}], [] }.
   base_expr -> sigil : build_sigil('$1').
   
   %% Blocks
  
positive.code: 
  %% Dots
  
  build_dot_ref(Dot, { '__aliases__', _, Left }, { 'aliases', _, Right }) ->
    { '__aliases__', [{line,?line(Dot)}], Left ++ Right };
  
  build_dot_ref(Dot, Other, { 'aliases', _, Right }) ->
    { '__aliases__', [{line,?line(Dot)}], [Other|Right] }.
  
  build_dot(Dot, Left, Right) ->
  
negative.code:   comp_op at_op unary_op and_op or_op arrow_op match_op
    range_op in_op inc_op when_op than_op default_op tail_op
    dual_op add_op mult_op exp_op two_op type_op stab_op
    'true' 'false' 'nil' 'do' eol ',' '.' '&'
    '(' ')' '[' ']' '{' '}' '<<' '>>'
    .
  
  