Re: [racket-users] Reason why char=? accepts only one argument?

2019-11-24 Thread George Neuner
On 11/24/2019 5:30 PM, Jonathan Simpson wrote: The documentation for char=? leaves the impression that it takes a minimum of two arguments: https://docs.racket-lang.org/reference/characters.html?q=expand#%28def._%28%28quote._~23~25kernel%29._char~3d~3f%29%29 If a single character is

[racket-users] Reason why char=? accepts only one argument?

2019-11-24 Thread Vityou
Not sure if this is the main reason, but say you are applying char=? to a list of unknown length to see if all elements are equal. It makes sense that a list with 1 element is a list with all elements equal. -- You received this message because you are subscribed to the Google Groups "Racket

Re: [racket-users] Newb question....About "How to Design Programs" book

2019-11-24 Thread Sam Tobin-Hochstadt
First, I strongly recommend the second edition, which is what you get at htdp.org. In that case, you'll do many things differently with respect to teachpacks, but the ideas will be very similar. Second, when you choose "Add Teachpack" from the "Language" menu in DrRacket, you should see three

Re: [racket-users] Newb question....About "How to Design Programs" book

2019-11-24 Thread Michael Burke
Thank you, Sam- I'm apparently reading a pdf version published in 2002 (Copyright 2001 Third Printing). Of course, it still refers to DrScheme and Scheme. Is there a newer one? I'm at Exercise 2.2.1, converting Fahrenheit to Celsius. The exercise calls for installing the teachpack

Re: [racket-users] Newb question....About "How to Design Programs" book

2019-11-24 Thread Sam Tobin-Hochstadt
Which edition of the book are you using? And can you point to where in the book you ran into trouble, and what happened? The full book is online, so a link to the section would be very helpful. Sam On Sun, Nov 24, 2019 at 9:28 PM Michael Burke wrote: > > I'm sure this has been asked and

[racket-users] Newb question....About "How to Design Programs" book

2019-11-24 Thread Michael Burke
I'm sure this has been asked and answered, but are their any current descriptions of how people are adjusting to the book, "How to Design Programs"? I ran into a problem on the first little exercise that required me to use a teachpack. Surely someone has a lit of work-around for this? Thanks,

[racket-users] Reason why char=? accepts only one argument?

2019-11-24 Thread Jonathan Simpson
The documentation for char=? leaves the impression that it takes a minimum of two arguments: https://docs.racket-lang.org/reference/characters.html?q=expand#%28def._%28%28quote._~23~25kernel%29._char~3d~3f%29%29 If a single character is passed as argument 1, char=? returns true. To me, '='

Re: [racket-users] question re downloading a PDF file

2019-11-24 Thread Tim Hanson
Thanks, Dominik, that appears to do the trick! (pdfgrep is immediately happy...). Much appreciated, Tim -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to

Re: [racket-users] question re downloading a PDF file

2019-11-24 Thread Dominik Pantůček
Hi, On 24. 11. 19 13:01, Tim Hanson wrote: > hi, > > I need to fetch a number of PDF documents and wrote a bit of racket to make > it easier. The part that "downloads" is this: > > (let ([content >((compose port->string get-pure-port string->url) (url-for-doc > year

[racket-users] question re downloading a PDF file

2019-11-24 Thread Tim Hanson
hi, I need to fetch a number of PDF documents and wrote a bit of racket to make it easier. The part that "downloads" is this: (let ([content ((compose port->string get-pure-port string->url) (url-for-doc year doc-name))]) (let ([out (open-output-file