úÎ7lP(c) Harvard University 2009-2011 : (c) Geoffrey Mainland 2011-2014 BSD-style*Geoffrey Mainland <mainland@cs.drexel.edu>None+'Unique identifier and the string itselfIntern a string to produce a . Return the  associated with a .     P(c) Harvard University 2009-2011 : (c) Geoffrey Mainland 2011-2014 BSD-style*Geoffrey Mainland <mainland@cs.drexel.edu> Trustworthy       symbol-0.2.4Data.Symbol.Unsafe Data.SymbolSymbolinternuninternbaseGHC.BaseString SymbolEnvuniqsymbols symbolEnv$fIsStringSymbol $fReadSymbol $fShowSymbol $fOrdSymbol $fEqSymbol