RosettaCodeData/Task/Text-processing-1/Racket/text-processing-1.rkt

55 lines
3.0 KiB
Racket

#lang racket
;; Use SRFI 48 to make %n.nf formats convenient.
(require (prefix-in srfi/48: srfi/48)) ; SRFI 48: Intermediate Format Strings
;; Parameter allows us to used exact decimal strings
(read-decimal-as-inexact #f)
;; files to read is a sequence, so it could be either a list or vector of files
(define (text-processing/1 files-to-read)
(define (print-line-info d r a t)
(srfi/48:format #t "Line: ~11F Reject: ~2F Accept: ~2F Line_tot: ~10,3F Line_avg: ~10,3F~%"
d r a t (if (zero? a) +nan.0 (/ t a))))
;; returns something that can be used as args to an apply
(define (handle-and-tag-max consecutive-false tag max-consecutive-false max-false-tags)
(let ((consecutive-false+1 (add1 consecutive-false)))
(list consecutive-false+1
(max max-consecutive-false consecutive-false+1)
(cond ((= consecutive-false+1 max-consecutive-false) (cons tag max-false-tags))
((= consecutive-false max-consecutive-false) (list tag))
(else max-false-tags)))))
(define (sub-t-p/1 N sum consecutive-false max-consecutive-false max-false-tags)
(for/fold ((N N) (sum sum) (consecutive-false consecutive-false) (max-consecutive-false max-consecutive-false) (max-false-tags max-false-tags))
((l (in-lines)))
(match l
[(app string-split `(,tag ,(app string->number vs.ss) ...))
(let get-line-pairs
((vs.ss vs.ss) (line-N 0) (reject 0) (line-sum 0) (consecutive-false consecutive-false)
(max-consecutive-false max-consecutive-false) (max-false-tags max-false-tags))
(match vs.ss
['()
(print-line-info tag reject line-N line-sum)
(values (+ N line-N) (+ sum line-sum) consecutive-false max-consecutive-false max-false-tags)]
[(list-rest v (? positive?) tl)
(get-line-pairs tl (add1 line-N) reject (+ line-sum v) 0 max-consecutive-false max-false-tags)]
[(list-rest _ _ tl)
(apply get-line-pairs tl line-N (add1 reject) line-sum
(handle-and-tag-max consecutive-false tag max-consecutive-false max-false-tags))]))]
(x (fprintf (current-error-port) "mismatch ~s~%" x)
(values N sum consecutive-false max-consecutive-false max-false-tags)))))
(for/fold ((N 0) (sum 0) (consecutive-false 0) (max-consecutive-false 0) (max-false-tags null))
((f files-to-read))
(with-input-from-file f
(lambda () (sub-t-p/1 N sum consecutive-false max-consecutive-false max-false-tags)))))
(let ((files (vector->list (current-command-line-arguments))))
(let-values (([N sum consecutive-false max-consecutive-false max-false-tags] (text-processing/1 files)))
(srfi/48:format #t "~%File(s) = ~a~%Total = ~10,3F~%Readings = ~6F~%" (string-join files) sum N)
(unless (zero? N) (srfi/48:format #t "Average = ~10,3F~%" (/ sum N)))
(srfi/48:format #t "~%Maximum run(s) of ~a consecutive false readings ends at line starting with date(s): ~a~%"
max-consecutive-false (string-join max-false-tags))))