[erlang-questions] How to make this work

Roelof Wobben r.wobben@REDACTED
Wed Aug 12 19:49:17 CEST 2015

Op 12-8-2015 om 19:20 schreef Fred Hebert:
> On 08/12, Roelof Wobben wrote:
>> Hello,
>> Im trying this exercise from the programming erlang book.
>> Roelof
> Hi Roelof.
> Honest advice here is that you really, really need to sit down and 
> read more carefully through the documentation you have at hand, and to 
> try experimenting with your programs a bit.  We've been through this 
> months ago already.
> Here's a quick list:
> Feb 2015:
> - http://erlang.org/pipermail/erlang-questions/2015-February/083087.html
> Valid question from the exercise book, because too simple of a 
> solution was indeed too simple.
> - http://erlang.org/pipermail/erlang-questions/2015-February/083162.html
> correct implementations, but you confused strings and atoms. Those 
> were exercises from 'Erlang Programming' book. Atoms are introduced on 
> p.19, the exercises on p.44. - 
> http://erlang.org/pipermail/erlang-questions/2015-February/083197.html
> This is a function again from Erlang Programming. The precise 
> implementation you are looking for for sum_acc/3 is on page 68, and is 
> not actually an exercise as mentioned
> - http://erlang.org/pipermail/erlang-questions/2015-February/083217.html
> You found a compile error for mismatching heads. I'm not sure when in 
> the book it is, but I'd like to show you the link 
> http://learnyousomeerlang.com/errors-and-exceptions#a-compilation-of-errors 
> where I compiled the common compile errors, with their explanation and 
> how to fix them.
> - http://erlang.org/pipermail/erlang-questions/2015-February/083233.html
> Valid enough question about list building, I have little to say here
> - http://erlang.org/pipermail/erlang-questions/2015-February/083240.html
> Error on the syntax of atoms, again introduced on p.19. The error *is* 
> a bit cryptic though
> - http://erlang.org/pipermail/erlang-questions/2015-February/083301.html
> Exercise from the Erlang programming book. Trying the guards you had 
> set in the shell with numbers would have revealed the problem directly 
> (as pointed out in the first response)
> Fast forward to this month:
> - http://erlang.org/pipermail/erlang-questions/2015-August/085382.html
> I'll point you for some like this to the same learnyousomeerlang link 
> in the future, it's also there!
> - http://erlang.org/pipermail/erlang-questions/2015-August/085410.html
> The problem there was an unexported function. The error you saw was 
> probably something like 'undef'. In this case, and for other errors 
> happening at runtime, I'd like to redirect you to 
> http://learnyousomeerlang.com/errors-and-exceptions#run-time-errors 
> which includes descriptions for such errors and ways to fix them in 
> general. Note that the error is also described on page 70 of Erlang 
> Programming.
> - http://erlang.org/pipermail/erlang-questions/2015-August/085419.html
> Dialyzer errors are legitimately confusing for a newcomer!
> - http://erlang.org/pipermail/erlang-questions/2015-August/085438.html
> Valid question from 'make it work -> make it beautiful' as a progress
> - http://erlang.org/pipermail/erlang-questions/2015-August/085496.html
> This very thread. The content there is from Programming Erlang 
> (Armstrong). If it's the second edition, I don't have it, but in the 
> first edition, the syntax to functions is explained on page 42. In 
> Erlang programming (which you also have), it's on page 190, and in 
> Etudes for Erlang, which you have also looked at, they're explained in 
> chapter 7 (http://chimera.labs.oreilly.com/books/1234000000726/ch07.html)
> Don't get me wrong, I appreciate people posting to the mailing list. 
> The thing is, I feel that it would be helpful for *your* learning as a 
> whole to make use of the resources you have rather than coming to the 
> list as often as you do. For one, the feedback loop and your progress 
> will be much faster!
> Out of the 12 email threads I have linked here, at least 6 of them 
> could have been solved by re-reading the learning material you have in 
> your hands (because that's where you take exercises and examples 
> from), or by experimenting rapidly with the shell.
> The other half were good questions to ask, so by all means, don't stop 
> asking questions. Just make sure that you're not using us as your own 
> private debugger!
> Old timers from the industry will tell you stories of when they had to 
> take punched cards or hand-written programs, had to go to their 
> university department to make them run, wait hours or days before 
> finding if things were alright, and then repeating this over again for 
> every bug.
> When you ask us to solve such problems for you while you have all the 
> information required, you might just be throwing yourself back 30-40 
> years in the past in terms of feedback loops!
> You've got the material, the tools, and visibly the drive to do that 
> stuff. It's likely going to be simpler in the long run to make a few 
> experiments, run them, and see if you can figure it out (or go back 
> and re-read significant chapters in one of the many books you have on 
> the topic) than the time it takes for you to write an email and wait 
> for a response.
> Regards,
> Fred.

oke, point taken.


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