Re: Functional Programming in D
https://garden.dlang.io/
Re: Functional Programming in D
On Wed, Oct 09, 2019 at 05:41:02PM +, Jonathan Gerlach via Digitalmars-d-learn wrote: > On Wednesday, 9 October 2019 at 14:26:53 UTC, NonNull wrote: > > Hello, > > I want to become fluent in the use of functional programming > > techniques in D (as well as the use of ranges) using std.functional > > (and std.algorithm and whatever else is relevant). Is there anything > > out there that isn't just module documentation that covers the full > > scope of this? > > I had this same feeling about wanting to learn `std.functional` a bit > more, so I decided to do https://adventofcode.com/ with additional > constraints that the code would be functional D with as many unit > tests as I could manage. I learned a bunch and had a lot of fun with > it. Actually, std.functional is somewhat of a misnomer. It mostly deals with higher-order functions, i.e., functions that return functions, currying, that sort of thing. These are part of functional programming, but there's more to functional programming than that. I'd say std.range and std.algorithm are another major part of functional-style programming support in D, along with the purity system. Here are some resources that might help get you started: https://klickverbot.at/blog/2012/05/purity-in-d/ https://tour.dlang.org/tour/en/basics/ranges http://ddili.org/ders/d.en/ranges.html http://dconf.org/2015/talks/davis.html http://www.informit.com/articles/printerfriendly.aspx?p=1407357=1 http://wiki.dlang.org/Component_programming_with_ranges T -- What did the alien say to Schubert? "Take me to your lieder."
Re: Functional Programming in D
On Wednesday, 9 October 2019 at 14:26:53 UTC, NonNull wrote: Hello, I want to become fluent in the use of functional programming techniques in D (as well as the use of ranges) using std.functional (and std.algorithm and whatever else is relevant). Is there anything out there that isn't just module documentation that covers the full scope of this? I had this same feeling about wanting to learn `std.functional` a bit more, so I decided to do https://adventofcode.com/ with additional constraints that the code would be functional D with as many unit tests as I could manage. I learned a bunch and had a lot of fun with it.
Re: ld errors in osx Catalina
On Wednesday, 9 October 2019 at 16:08:41 UTC, rikki cattermole wrote: On 09/10/2019 11:33 PM, David Briant wrote: [...] D as a native language links against libc, so using the system c compiler as the linker is a viable method to prevent having to look things up. Perhaps try ldc? That uses LLVM so may be better on OSX. Related: https://issues.dlang.org/show_bug.cgi?id=20019 Also those versions on homebrew look to be at least one version out of date. If ldc on homebrew doesn't work, you should try the versions on the main site (which has dmg's) https://dlang.org/download.html I confirm that ldc-1.18.0-beta2 works fine on mine Catalina, downloaded and activated with the official install script. /Paolo
Re: ld errors in osx Catalina
On 09/10/2019 11:33 PM, David Briant wrote: I've accidentally upgraded to Catalina - a little earlier than planned as I had hoped not to be trail blazing! My problem is this, in a bash shell and a new directory when I run $ dub init ... answering the questions that dub asks $ dub dmd compiles the skeleton project but ld fails (full dump below). I've tried uninstalling dub, dmd (via homebrew) and reinstalling (had to use the latest beta) and upgrading xcode and also upgrading to Catalina. I'm a d newbie and this is my first escapade into compiling on the mac. Has anyone an idea how to fix this? D as a native language links against libc, so using the system c compiler as the linker is a viable method to prevent having to look things up. Perhaps try ldc? That uses LLVM so may be better on OSX. Related: https://issues.dlang.org/show_bug.cgi?id=20019 Also those versions on homebrew look to be at least one version out of date. If ldc on homebrew doesn't work, you should try the versions on the main site (which has dmg's) https://dlang.org/download.html
Re: ld errors in osx Catalina
On Wednesday, 9 October 2019 at 15:42:42 UTC, David Briant wrote: On Wednesday, 9 October 2019 at 10:33:21 UTC, David Briant wrote: [...] If I uninstall clang using conda I now get: (base) Davids-MacBook:fred david$ dub Performing "debug" build using /Library/D/dmd/bin/dmd for x86_64. fred ~master: building configuration "application"... Linking... x86_64-apple-darwin13.4.0-clang: No such file or directory core.thread.ThreadError@src/core/thread.d(3093): Unable to load thread state Error: linker exited with status 255 /Library/D/dmd/bin/dmd failed with exit code 1. It seems like dub has somehow gotten entwined with the anaconda compiler - any ideas how to fix? FYI Solution was to use anaconda-clean to remove anaconda completely, then uninstall dmd using homebrew then reinstall the beta version.
Re: ld errors in osx Catalina
On Wednesday, 9 October 2019 at 10:33:21 UTC, David Briant wrote: I've accidentally upgraded to Catalina - a little earlier than planned as I had hoped not to be trail blazing! My problem is this, in a bash shell and a new directory when I run $ dub init ... answering the questions that dub asks $ dub dmd compiles the skeleton project but ld fails (full dump below). I've tried uninstalling dub, dmd (via homebrew) and reinstalling (had to use the latest beta) and upgrading xcode and also upgrading to Catalina. I'm a d newbie and this is my first escapade into compiling on the mac. Has anyone an idea how to fix this? If I uninstall clang using conda I now get: (base) Davids-MacBook:fred david$ dub Performing "debug" build using /Library/D/dmd/bin/dmd for x86_64. fred ~master: building configuration "application"... Linking... x86_64-apple-darwin13.4.0-clang: No such file or directory core.thread.ThreadError@src/core/thread.d(3093): Unable to load thread state Error: linker exited with status 255 /Library/D/dmd/bin/dmd failed with exit code 1. It seems like dub has somehow gotten entwined with the anaconda compiler - any ideas how to fix?
Functional Programming in D
Hello, I want to become fluent in the use of functional programming techniques in D (as well as the use of ranges) using std.functional (and std.algorithm and whatever else is relevant). Is there anything out there that isn't just module documentation that covers the full scope of this?
Re: Blog Post #77: Notebook, Part I
On Wednesday, 9 October 2019 at 09:44:39 UTC, Ron Tarrant wrote: On Wednesday, 9 October 2019 at 03:13:48 UTC, GreatSam4sure wrote: Good works Thanks, GreatSam4sure. Is there any way to detect the size of my screen using gtkd? So that incan calculate the size of my screen and center my window on the screen using move(x, y). I had a quick look into this and there is no straightforward solution, so I can't give you an immediate answer. It would be easier to explain with a demo, so I'll need some time to work one up. I've put it on my to-do list. Besides can you convert all your posts to a pdf that is easily downloadable for those with little internet access? I've been thinking about an ebook based on the blog, something that would start with installing a development environment, go into how to organize and write each part of an application, and end with how to distribute the finished product. It's in very early stages ATM, but I'm open to any suggestions you (or anyone else) may have for how to make it as useful as possible. Thanks, it will be better to use coded. It is very easy to stand a gtkd project in coded and vs code. All dependency taking care of. Dub will download the dependency for if you are connected to the internet
Have DUB sub packages inherit settings
I want to split my package into sub packages for faster
compilation, but I have some custom settings that I don't want to
copy-paste 10 times since that makes editing them really
annoying. Is there a way to inherit the settings from the
main-package, or avoid repetition in another way?
I found this 2 years old post:
https://forum.dlang.org/post/wdkrsfjfbtnmpxcgu...@forum.dlang.org
It is mentioned that when using --combined the flags are
inherited, but I also want to inherit the settings when not using
that flag.
The settings in question are:
```
dflags "-dip1000" "-dip25"
buildType "debug" {
buildOptions "debugMode" "debugInfo"
buildOptions "betterC"
buildRequirements "allowWarnings"
}
buildType "release" {
buildOptions "releaseMode" "optimize" "inline"
buildOptions "betterC"
}
buildType "unittest" {
buildOptions "unittests" "debugMode" "debugInfo"
dflags "-checkaction=context"
buildRequirements "allowWarnings"
}
```
Re: formatting a float or double in a string with all significant digits kept
On Tuesday, 8 October 2019 at 20:37:03 UTC, dan wrote:
I have a double precision number that i would like to print all
significant digits of, but no more than what are actually
present in the number. Or more exactly, i want to print the
minimum number of digits necessary to recover the original
number to within 2 or 3 least significant bits in the stored,
in-core, version of its bit pattern.
For example,
import std.string;
import std.stdio;
import std.math;
void main( ) {
auto t = format("%3.30f", PI );
writeln("Value of PI is: ", PI, " or, : ", t);
}
The default way writeln prints is 5 digits to the right of the
decimal point.
I can format to print with any number of digits, such as 30
above, but that's too many.
For pi, the correct number of digits to print looks to be about
18 (and the extra 12 digits presumably are from the decimal
expansion of the least significant bit?).
But i would like to be able to do this without knowing the
expansion of pi, or writing too much code, especially if
there's some d function like writeAllDigits or something
similar.
Thanks in advance for any pointers!
dan
Hi Dan,
What's your usecase here, e.g. a csv/json reader / writer? You
say it's for double precision numbers (64bit format) then provide
an example for reals (80bit format). So I'm not certain your goal.
If you google "what every developer should know about doubles"
you'll hit a number of useful articles that explain the common
issues of floating point representation in detail.
-- David
ld errors in osx Catalina
I've accidentally upgraded to Catalina - a little earlier than planned as I had hoped not to be trail blazing! My problem is this, in a bash shell and a new directory when I run $ dub init ... answering the questions that dub asks $ dub dmd compiles the skeleton project but ld fails (full dump below). I've tried uninstalling dub, dmd (via homebrew) and reinstalling (had to use the latest beta) and upgrading xcode and also upgrading to Catalina. I'm a d newbie and this is my first escapade into compiling on the mac. Has anyone an idea how to fix this? (base) Davids-MacBook:fred david$ dub Performing "debug" build using /Library/D/dmd/bin/dmd for x86_64. fred ~master: building configuration "application"... Linking... ld: warning: ignoring file /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib/libpthread.tbd, file was built for unsupported file format ( 0x2D 0x2D 0x2D 0x20 0x21 0x74 0x61 0x70 0x69 0x2D 0x74 0x62 0x64 0x2D 0x76 0x33 ) which is not the architecture being linked (x86_64): /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib/libpthread.tbd ld: warning: ignoring file /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib/libm.tbd, file was built for unsupported file format ( 0x2D 0x2D 0x2D 0x20 0x21 0x74 0x61 0x70 0x69 0x2D 0x74 0x62 0x64 0x2D 0x76 0x33 ) which is not the architecture being linked (x86_64): /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib/libm.tbd ld: warning: ignoring file /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib/libSystem.tbd, file was built for unsupported file format ( 0x2D 0x2D 0x2D 0x20 0x21 0x74 0x61 0x70 0x69 0x2D 0x74 0x62 0x64 0x2D 0x76 0x33 ) which is not the architecture being linked (x86_64): /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib/libSystem.tbd Undefined symbols for architecture x86_64: "__NSGetMachExecuteHeader", referenced from: __D2rt9backtrace5dwarf23traceHandlerOpApplyImplFxAPvMDFKmKxAaZiZi in libphobos2.a(dwarf_9d0_924.o) "__Unwind_DeleteException", referenced from: ___dmd_personality_v0 in libphobos2.a(dwarfeh_892_811.o) ___dmd_begin_catch in libphobos2.a(dwarfeh_88f_6b9.o) "__Unwind_GetIP", referenced from: ___dmd_personality_v0 in libphobos2.a(dwarfeh_892_811.o) "__Unwind_GetLanguageSpecificData", referenced from: ___dmd_personality_v0 in libphobos2.a(dwarfeh_892_811.o) "__Unwind_GetRegionStart", referenced from: ___dmd_personality_v0 in libphobos2.a(dwarfeh_892_811.o) "__Unwind_RaiseException", referenced from: __d_throwdwarf in libphobos2.a(dwarfeh_891_56a.o) "__Unwind_Resume", referenced from: __D3std5stdio__T7writelnTAyaZQnFNfQjZv in fred.o __D3std5stdio4File8opAssignMFNcNjNfSQBhQBgQBdZQl in libphobos2.a(stdio_19dd_180.o) __D3std5stdio4File6reopenMFNeAyaMAxaZv in libphobos2.a(stdio_19dd_180.o) __D3std5stdio4File6fdopenMFNeiMAxaAyaZv in libphobos2.a(stdio_19dd_180.o) __D3std5stdio4File6detachMFNeZv in libphobos2.a(stdio_19dd_180.o) __D3std5stdio4File5closeMFNeZv in libphobos2.a(stdio_19dd_180.o) __D3std5stdio4File11ByChunkImpl6__ctorMFNcSQBoQBnQBkmZSQCaQBzQBwQBu in libphobos2.a(stdio_19dd_180.o) ... "__Unwind_SetGR", referenced from: ___dmd_personality_v0 in libphobos2.a(dwarfeh_892_811.o) "__Unwind_SetIP", referenced from: ___dmd_personality_v0 in libphobos2.a(dwarfeh_892_811.o) "___error", referenced from: __D3std5stdio4File7tryLockMFEQBaQz8LockTypemmZb in libphobos2.a(stdio_19dd_180.o) __D3std9exception14ErrnoException6__ctorMFNfAyaQdmZCQBxQBwQBp in libphobos2.a(exception_489_5b5.o) __d_run_main2 in libphobos2.a(dmain2_888_4ad.o) __D4core6thread6Thread5sleepFNbNiSQBf4time8DurationZv in libphobos2.a(thread_386_258.o) _fakePureReprintReal in libphobos2.a(demangle_2ff_79b.o) "___stderrp", referenced from: ___dmd_personality_v0 in libphobos2.a(dwarfeh_892_811.o) __d_throwdwarf in libphobos2.a(dwarfeh_891_56a.o) __D2rt7dwarfeh8scanLSDAFPxhmmbbPSQBe6unwind17_Unwind_ExceptionJmJiZEQCnQCn10LsdaResult in libphobos2.a(dwarfeh_896_2c9.o) __D2rt6dmain218_d_print_throwableUC6object9ThrowableZ4sinkMFNbNiNlMxAaZv in libphobos2.a(dmain2_88b_776.o) __d_run_main2 in libphobos2.a(dmain2_888_4ad.o) __D2rt6dmain212_d_run_main2UAAamPUQgZiZ6runAllMFZv in libphobos2.a(dmain2_888_4ad.o) __D2rt7dwarfeh17actionTableLookupFPSQBh6unwind17_Unwind_ExceptionkPxhQdhmQhZi in libphobos2.a(dwarfeh_897_6e0.o) ... "___stdoutp", referenced from: __D3std5stdio__T10makeGlobalVEQBbQBa13StdFileHandlea22_636f72652e737464632e737464696f2e7374646f7574ZQDgFNbNcNdNiZSQEhQEg4File in libphobos2.a(stdio_19e9_cfb.o) __d_run_main2 in libphobos2.a(dmain2_888_4ad.o) "__dyld_get_image_header", referenced from: __D2rt19sections_osx_x86_6411getTLSRangeFNbNixPvZAv in libphobos2.a(sections_osx_x86_64_93f_420.o) "__dyld_image_count", referenced from:
Re: Blog Post #77: Notebook, Part I
On Wednesday, 9 October 2019 at 03:13:48 UTC, GreatSam4sure wrote: Good works Thanks, GreatSam4sure. Is there any way to detect the size of my screen using gtkd? So that incan calculate the size of my screen and center my window on the screen using move(x, y). I had a quick look into this and there is no straightforward solution, so I can't give you an immediate answer. It would be easier to explain with a demo, so I'll need some time to work one up. I've put it on my to-do list. Besides can you convert all your posts to a pdf that is easily downloadable for those with little internet access? I've been thinking about an ebook based on the blog, something that would start with installing a development environment, go into how to organize and write each part of an application, and end with how to distribute the finished product. It's in very early stages ATM, but I'm open to any suggestions you (or anyone else) may have for how to make it as useful as possible.
Re: formatting a float or double in a string with all significant digits kept
On Wednesday, 9 October 2019 at 07:16:43 UTC, Jon Degenhardt
wrote:
On Wednesday, 9 October 2019 at 05:46:12 UTC, berni44 wrote:
On Tuesday, 8 October 2019 at 20:37:03 UTC, dan wrote:
But i would like to be able to do this without knowing the
expansion of pi, or writing too much code, especially if
there's some d function like writeAllDigits or something
similar.
You can use the property .dig to get the number of significant
digits of a number:
writeln(PI.dig); // => 18
You still need to account for the numbers before the dot. If
you're happy with scientific notation you can do:
auto t = format("%.*e", PI.dig, PI);
writeln("PI = ",t);
Using the '.dig' property is a really nice idea and looks very
useful for this. A clarification though - It's the significant
digits in the data type, not the value. (PI is 18 because it's
a real, not a double.) So:
writeln(1.0f.dig, ", ", float.dig); => 6, 6
writeln(1.0.dig, ", ", double.dig); => 15, 15
writeln(1.0L.dig, ", ", real.dig); => 18, 18
Another possibility would be to combine the '.dig' property
with the "%g" option, similar to the use "%e" shown. For
example, these lines:
writeln(format("%0.*g", PI.dig, PI));
writeln(format("%0.*g", double.dig, 1.0));
writeln(format("%0.*g", double.dig, 100.0));
writeln(format("%0.*g", double.dig, 1.0001));
writeln(format("%0.*g", double.dig, 0.0001));
produce:
3.14159265358979324
1
100
1.0001
1e-08
Hopefully experimenting with the different formatting options
available will yield one that works for your use case.
Good solution
But what does it takes to leave a number the way it is without
formatting automatic to 6 significant figure out how that
requires such a work around as shown above. I know C language is
the same but must D follow suit.
One of the compilers, i think the DMD 2.084 (not sure now)
correct but now the recent one's have revert back. Every number
should be left the way it is like java, C#(not sure),
actionscript, javascript, etc.
I don't think it will take that much effort for trivial things
like to stress developers.
This is the best solution i have ever seen on this issue on the
forum.i have ask this question several times on this forum
Re: formatting a float or double in a string with all significant digits kept
On Wednesday, 9 October 2019 at 05:46:12 UTC, berni44 wrote:
On Tuesday, 8 October 2019 at 20:37:03 UTC, dan wrote:
But i would like to be able to do this without knowing the
expansion of pi, or writing too much code, especially if
there's some d function like writeAllDigits or something
similar.
You can use the property .dig to get the number of significant
digits of a number:
writeln(PI.dig); // => 18
You still need to account for the numbers before the dot. If
you're happy with scientific notation you can do:
auto t = format("%.*e", PI.dig, PI);
writeln("PI = ",t);
Using the '.dig' property is a really nice idea and looks very
useful for this. A clarification though - It's the significant
digits in the data type, not the value. (PI is 18 because it's a
real, not a double.) So:
writeln(1.0f.dig, ", ", float.dig); => 6, 6
writeln(1.0.dig, ", ", double.dig); => 15, 15
writeln(1.0L.dig, ", ", real.dig); => 18, 18
Another possibility would be to combine the '.dig' property with
the "%g" option, similar to the use "%e" shown. For example,
these lines:
writeln(format("%0.*g", PI.dig, PI));
writeln(format("%0.*g", double.dig, 1.0));
writeln(format("%0.*g", double.dig, 100.0));
writeln(format("%0.*g", double.dig, 1.0001));
writeln(format("%0.*g", double.dig, 0.0001));
produce:
3.14159265358979324
1
100
1.0001
1e-08
Hopefully experimenting with the different formatting options
available will yield one that works for your use case.
