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#lang racket/base
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(require "define/contract.rkt" "coerce.rkt")
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(define+provide/contract (starts-with? str starter)
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(coerce/string? coerce/string? . -> . coerce/boolean?)
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(and (<= (string-length starter) (string-length str))
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(equal? (substring str 0 (string-length starter)) starter)))
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(define+provide/contract (ends-with? str ender)
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(coerce/string? coerce/string? . -> . coerce/boolean?)
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(and (<= (string-length ender) (string-length str))
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(equal? (substring str (- (string-length str) (string-length ender)) (string-length str)) ender)))
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