postfix to infix by flagitious(sym)

@_=->__{_='+-*/'=~/[\\#{$_[/.$/]}]/;~/.$/;$_=$`
_ ?(___=$&+@_[_];@__=@_[_&=~-~(_-_)]+___;_<__ ?"(#@__)":@__):$&}
(__=->_,*___{$_=_;$><<@_[-$$]<<$/;__[*___]})[*$<]

Note that non-ascii characters in the above source code will be escaped (such as \x9f).

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