IRC channel logs

<mark_weaver>tupi`: you around?

<Madsy>Hey mark_weaver

<Madsy>I'll see if I can test the latest guile sources tomorrow

<Madsy>If I can remember the build process that is :)

<mark_weaver>it you could keep notes of how to build it, that would be helpful.

<mark_weaver>tupi`: the reason that number is not being printed as 0.3 is because it's not the float that's closest to 0.3.

<mark_weaver>ultimately, the bug is in whatever code parsed that "0.3" and turned it into a float. if you used guile to do that conversion, it would work properly and print as 0.3.

<mark_weaver>also, the sqlite3 terminal has imprecise numeric output. it would presumably print two different values the same way. at least I hope it would print the value closest to 0.3 as "0.3". it is printing a number that's different from the closest value as "0.3" also, so the output is lossy.

<mark_weaver>here is the closest IEEE 754 double to 3/10: 0.010011001100110011001100110011001100110011001100110011

<mark_weaver>that's written in binary, and that last '1' is the least significant bit in the IEEE double representation.

<mark_weaver>the number that's in your sqlite3 database is this: 0.010011001100110011001100110011001100110011001100110100

<mark_weaver>so it was incorrectly rounded by the numeric input routine.

<mark_weaver>on the other hand, maybe 0.3 wasn't converted from a string. maybe it was computed in some way. in that case, it can't be helped if the computations and/or intermediate values are represented in binary. 1/10 can't be represented precisely in binary, so it's like computing 1/3 in decimal and then multiplying by 3 and getting 0.999999999999. it can't be helped.

<mark_weaver>you could either use exact rationals, or round off the last few digits and hope that the error is confined to those last few digits.

<mark_weaver>or you could represent durations as milliseconds (or maybe hundredths or tenths).

<nalaginrut>is there tree shaker in current master?

<sdl>1

<wingo> http://sockpuppet.org/blog/2014/02/25/safely-generate-random-numbers/

<atheia>g'morning guilers

<wingo>moin

<atheia>neat b-day hack — the demo was very… peaceful :-)

<nalaginrut>nice, I should update the session id generator of Artanis ;-)

<nalaginrut>mozilla try to invent a new browser with Rust

<nalaginrut>reinvent

<wingo>tx :)

<ArneBab>I added the comments from mark_weaver about foof-loop and SRFI-42 into my path from python to guile: http://draketo.de/proj/py2guile/#sec-5-1-2-5

<add^_>Uh, if a struct I want to parse contains a char array, how do I go about that?

<add^_>The (system foreign) list of types doesn't show char..

<add^_>Maybe I can make it an 8bit int that I convert to char later?

<add^_>:-/

<add^_>The struct I want to parse contains a char tag[];....

<add^_>err.. char tag[32];

<add^_>w/e

<lloda>does Guile have a path library? something like os.path in Python...

<add^_>path library?

<lloda>like os.path.join(path, dir, dir, basename)

<lloda>takes care of / vs \\, dunno

<add^_>I think it's even part of guile per default, but that is if I'm thinking of the same thing..