%w(
true false nil int float str dstr str
sym dsym xstr regopt regexp array splat
array pair kwsplat hash irange erange self
lvar ivar cvar gvar const defined? lvasgn
ivasgn cvasgn gvasgn casgn mlhs masgn op_asgn
op_asgn and_asgn ensure rescue arg_expr
or_asgn and_asgn or_asgn back_ref nth_ref
match_with_lvasgn match_current_line
module class sclass def defs undef alias args
cbase arg optarg restarg blockarg block_pass args def kwarg kwoptarg
kwrestarg send super zsuper yield block send
and not or if when case while until while_post
until_post for break next redo return resbody
kwbegin begin retry preexe postexe iflipflop eflipflop
shadowarg
).map(&:to_sym).to_set.freeze