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  • Subin Velleringatt thinks this is interesting:

However, if a dynamic variable already exists with the same name, let will instead, temporarily, override the value of the dynamic variable to the new value. *standard-output* is such a dynamic variable. This means that we can temporarily override the value of *standard-output* to a new value by passing it into our with-open-file command .


Cover of Land of Lisp


Didnt quite understand.