11 lines
293 B
Racket
11 lines
293 B
Racket
#lang racket/base
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(provide verbose vprintf)
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(define verbose (make-parameter #f))
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;; like printf but only in verbose mode
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(define o (current-output-port))
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(define (vprintf #:printer [printer printf] . a)
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(when (verbose)
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(parameterize ([current-output-port o])
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(apply printer a))))
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