8 lines
189 B
Racket
8 lines
189 B
Racket
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#lang racket
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(define ns (make-base-namespace))
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(define (eval-with-x code a b)
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(define (with v)
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(namespace-set-variable-value! 'x v #f ns)
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(eval code ns))
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(- (with b) (with a)))
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