This is not this kind of problem.
On Jun 25, 2012, at 10:06 AM, Richard Cleis wrote: > That is-near a better solution ;o) > > I think HtDP has problems that require assembling sentences from different > parts of speech. That is a very challenging software field. > > rac > > > > On Jun 25, 2012, at 12:41 AM, Roelof Wobben wrote: > >> You mean something like this : >> >> (check-expect (calculate 0 3) 3) >> (define (calculate getal1 getal2) >> (cond >> [ (equal? getal1 0) getal2] >> [ (equal? getal2 0) getal1] >> [else (sqrt (+ (* getal1 getal1) (* getal2 getal2)))] >> )) >> >> ; String -> String >> ; This function produces a string depending on the input "niet " or "" >> (check-expect (afdrukken "") "Het ingegeven punt is dichtbij het 0 punt") >> (check-expect (afdrukken "niet ") "Het ingegeven punt is niet dichtbij het 0 >> punt") >> (define (afdrukken s) >> (string-append first_tekst s middle_tekst) >> ) >> >> >> ; Struct -> String >> ; Function who outputs "niet" or a empty string depending on the calculated >> distance compared with R. >> (check-expect (is-near (make-posn 1 0) 5) "Het ingegeven punt is dichtbij >> het 0 punt") >> (check-expect (is-near (make-posn 3 4) 5) "Het ingegeven punt is niet >> dichtbij het 0 punt") >> (define (is-near s r) >> ( if (< (calculate (posn-x s) (posn-y s)) r) (afdrukken "") (afdrukken "niet >> ") >> )) >> >> >> Roelof >> >> >> >> Op 25-6-2012 6:18, Richard Cleis schreef: >>> Check-expect is used to test your function. >>> Make that work first. >>> >>> Then you can use the design recipe to make a new function. >>> >>> The new function will accept the output of your first function and return >>> the message that you want… without any repeated words in the function. >>> >>> rac >>> >>> On Jun 24, 2012, at 1:43 PM, Roelof Wobben wrote: >>> >>>> Hello, >>>> >>>> This soluation is not what I was looking for. >>>> And it uses list which I don't have learned so far. >>>> >>>> So far I have this : >>>> >>>> ; constanten >>>> >>>> (define R 5) >>>> (define first_tekst "Het ingegeven punt") >>>> (define is_tekst "is") >>>> (define middle_tekst "dichtbij het 0 nulpunt") >>>> (define niet "niet") >>>> >>>> >>>> ;Number Number -> Number >>>> ;This function calculates the distance of a given point compared to the >>>> origin >>>> (check-expect (calculate 1 0) 1) >>>> (check-expect (calculate 3 4) 5) >>>> (check-expect (calculate 0 3) 3) >>>> (define (calculate getal1 getal2) >>>> (cond >>>> [ (equal? getal1 0) getal2] >>>> [ (equal? getal2 0) getal1] >>>> [else (sqrt (+ (* getal1 getal1) (* getal2 getal2)))] >>>> )) >>>> >>>> ; Struct -> String >>>> ; Function who outputs a string dependinh on the outcome of the >>>> calculation of the distance to the origin >>>> (check-expect (is-near (make-s 1 0) "Het ingegeven punt is dichtbij het >>>> nulpunt")) >>>> (check-expect (is-near (make-s 3 4) "Het ingeven punt is niet dichtbij het >>>> nulpunt")) >>>> (define (is-near s r) >>>> ( if (< (calculate (posn-x s) (posn-y s)) r) >>>> >>>> Now I can do (string append first_tekst is middle-tekst) and >>>> (string-append first-tekst is niet middle-tekst) but then I do almost >>>> two times the same with one difference the niet part. >>>> And Im looking for a better solution. >>>> >> >> > > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
