Ruby Fail
irb(main):001:0> :[]= => :[]= irb(main):002:0> [:[]=] => [:[]=] irb(main):003:0> [:]=] SyntaxError: compile error (irb):3: syntax error, unexpected ']', expecting tSTRING_CONTENT or tSTRING_DBEG or tSTRING_DVAR or tSTRING_END [:]=] ^ from (irb):3 from :0 irb(main):004:0> :] SyntaxError: compile error (irb):4: syntax error, unexpected ']', expecting tSTRING_CONTENT or tSTRING_DBEG or tSTRING_DVAR or tSTRING_END from (irb):4 from :0