Hi Arthur, I need a list of lists because each line has more than one number. You first solution works for me. All I need to do is to add an extra string-split call, which returns a list.
Thanks a lot! Jinsong On Tue, Jul 12, 2016 at 11:52 PM, Arthur Maciel <arthurmac...@gmail.com> wrote: > Although I can't imagine why you'd need it, but in order to get list of > lists you could do: > > (define (read-all-lines filename) > (with-input-from-file filename > (lambda () > (map (lambda (x) > (list (string->number x))) > (read-lines))))) > > I'm not sure that's what you want. > > Cheers, > Arthur > > > On Wed, Jul 13, 2016 at 12:49 AM, Jinsong Liang <jinsongli...@gmail.com> > wrote: > >> Hi Arthur, >> >> This simplifies my code a lot! I will give it a try. >> >> Thank you! >> >> Jinsong >> >> On Tue, Jul 12, 2016 at 11:45 PM, Arthur Maciel <arthurmac...@gmail.com> >> wrote: >> >>> Jinsong, the closest solution I can think of is the read-lines >>> procedure, which returns a list of strings (each string a line read). >>> >>> http://api.call-cc.org/doc/extras/read-lines >>> >>> Supposing you have a number per line, you could use string->number to >>> get the result. >>> >>> An example would be: >>> >>> (define (read-all-lines filename) >>> (with-input-from-file filename >>> (lambda () >>> (map string->number (read-lines))))) >>> >>> Cheers, >>> Arthur >>> >>> >>> On Wed, Jul 13, 2016 at 12:07 AM, Jinsong Liang <jinsongli...@gmail.com> >>> wrote: >>> >>>> Hi, >>>> >>>> I need to read a file (lines of numbers) into a list of lists with each >>>> line a list. I wrote the following function to do it: >>>> >>>> (define (read-all-lines file-name) >>>> (let ([output '()]) >>>> (let ([p (open-input-file file-name)]) >>>> (let f ([x (read-line p)]) >>>> (if (eof-object? x) >>>> (close-input-port p) >>>> (begin >>>> (set! output (cons (string-split x) output)) >>>> (f (read-line p)))))) >>>> (reverse output))) >>>> >>>> I have a few questions regarding the above code: >>>> >>>> 1. Is there an existing API to do the same thing? >>>> 2. Using set! seems not a lispy coding style. Is it true? >>>> 3. Any improvements I can make ? I bet there are tons. >>>> >>>> Thank you! >>>> >>>> Jinsong >>>> >>>> _______________________________________________ >>>> Chicken-users mailing list >>>> Chicken-users@nongnu.org >>>> https://lists.nongnu.org/mailman/listinfo/chicken-users >>>> >>>> >>> >> >
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