Philippe Sigaud:
So yes, D does not have Haskell nice syntax for pattern
matching.
I'd like some of such syntax for templates (and a little
different syntax added to match structs inside switch statements:
https://d.puremagic.com/issues/show_bug.cgi?id=596 ).
Bye,
bearophile
Timothee Cour:
auto byKeyValue(){...}
It's probably better to call the method byPair that is shorter.
If I/someone does it, will it be merged in?
Some people want those pairs to be tuples. But D lacks built-in
tuples, so you need to use typecons ones. But to use the typecons
ones you
On Friday, 14 February 2014 at 07:35:34 UTC, Timothee Cour wrote:
That seems like a worthy enhancement.
If I/someone does it, will it be merged in?
I really want it to happen, but I also want it to happen right.
See the relevant pull request[1].
[1]
On Fri, 14 Feb 2014 02:48:51 -, Jesse Phillips
jesse.k.phillip...@gmail.com wrote:
On Thursday, 13 February 2014 at 14:30:41 UTC, Regan Heath wrote:
Don't get me wrong, counting the elements as you iterate over them is
useful, but it isn't the index into the range you're likely after.
On Friday, 14 February 2014 at 12:10:51 UTC, Regan Heath wrote:
FWIW I disagree. I think it's immediately and intuitively
obvious what 'i' should be when you're foreaching over X items
taken from another range, even if you do not know take returns
another range. Compare it to calling a
is there a function to get the inverse of escapeShellCommand?
ie:
assert(escapeShellCommandInverse(` foo 'hello world' `)==[`foo`, `hello
world`]);
Regan Heath:
FWIW I disagree. I think it's immediately and intuitively
obvious what 'i' should be when you're foreaching over X items
taken from another range, even if you do not know take returns
another range. Compare it to calling a function on a range and
foreaching on the result, you
On Friday, 14 February 2014 at 06:05:08 UTC, Philippe Sigaud
wrote:
`alias` is just a bit of syntax sugar, it does not (at least for
2.064) have the same power than fully defining a template and
the `is(...)` expression.
Right. What I was saying, however, is it is strange to me that
this
Meta:
While it is heavier than Haskell's syntax, I have been
consistently and pleasantly surprised by how powerful D's
template pattern matching is (bugs notwithstanding). I wonder
how well-known this is outside this mailing list...
I keep reading blog posts that use Haskell and present
Hiho,
I am fairly new to the D programming and still reading throught
the awesome online book at http://ddili.org/ders/d.en/index.html.
However, I think it is missing some things or I am missing
glasses and overlooked these parts in the book.^^
Currently I am trying to write a very simple
On Friday, 14 February 2014 at 16:00:09 UTC, Robin wrote:
this(size_t rows, size_t cols) {
this.dim = Dimension(rows, cols);
this.data = new T[this.dim.size];
enum nil = to!T(0);
foreach(ref T element; this.data) element = nil;
}
I am no expert at optimizing D
On Friday, 14 February 2014 at 16:40:31 UTC, Craig Dillabaugh
wrote:
On Friday, 14 February 2014 at 16:00:09 UTC, Robin wrote:
this(size_t rows, size_t cols) {
this.dim = Dimension(rows, cols);
this.data = new T[this.dim.size];
enum nil = to!T(0);
foreach(ref T
Robin:
class Matrix(T = double) {
private T[] data;
private Dimension dim;
}
Also try final class or struct in your benchmark. And try to
use ldc2 compiler for performance benchmarks.
Perhaps dim is better const, unless you want to change the shape
of the matrix.
Craig Dillabaugh:
this.data = new T[this.dim.size];
with:
this.data.length = this.dim.size
It's the same thing.
Bye,
bearophile
On Fri, 14 Feb 2014 13:14:51 -, bearophile bearophileh...@lycos.com
wrote:
Regan Heath:
FWIW I disagree. I think it's immediately and intuitively obvious what
'i' should be when you're foreaching over X items taken from another
range, even if you do not know take returns another
On Fri, 14 Feb 2014 12:29:49 -, Jakob Ovrum jakobov...@gmail.com
wrote:
On Friday, 14 February 2014 at 12:10:51 UTC, Regan Heath wrote:
FWIW I disagree. I think it's immediately and intuitively obvious what
'i' should be when you're foreaching over X items taken from another
range,
On Friday, 14 February 2014 at 16:47:32 UTC, John Colvin wrote:
On Friday, 14 February 2014 at 16:40:31 UTC, Craig Dillabaugh
wrote:
On Friday, 14 February 2014 at 16:00:09 UTC, Robin wrote:
this(size_t rows, size_t cols) {
this.dim = Dimension(rows, cols);
this.data = new
On Friday, 14 February 2014 at 16:00:09 UTC, Robin wrote:
This is my class with its templated data as a one dimensional
array (as I don't like jagged-arrays) and a dimension (which is
a struct). The dimension object has some util functionality
such as getting the total size or mapping (row,
Regan Heath:
In my case I didn't need any of these.
I don't understand.
Bye,
bearophile
Isn't this discussion about adding an index to a range? If it is,
then I have shown why adding it in the language is a bad idea.
Bye,
bearophile
Chris Cain:
http://dlang.org/phobos/std_array.html#.uninitializedArray
minimallyInitializedArray should be used, because it's safer.
Bye,
bearophile
On Friday, 14 February 2014 at 16:00:09 UTC, Robin wrote:
class Matrix(T = double) {
T opIndex(size_t row, size_t col) const {
First of all make sure you it's not virtual, otherwise each
element access will cost you enough to make it 10x slower than
Java.
On Friday, 14 February 2014 at 16:56:29 UTC, bearophile wrote:
Craig Dillabaugh:
this.data = new T[this.dim.size];
with:
this.data.length = this.dim.size
It's the same thing.
Bye,
bearophile
Not quite. Setting length will copy over the existing contents of
the array. Using new
On Friday, 14 February 2014 at 16:00:09 UTC, Robin wrote:
As I am very new to D I instantly ran into certain optimizing
issues. E.g. the simple matrix multiplication based in my java
implementation requires about 1.5 secs for multiplying two
1000x1000 matrices, however my D implementation
I'm new to D, and I find it quite enjoyable so far.
I have however stumbled upon a problem which I can't seem to
figure out.
I am trying to make a program that creates a child process,
writes something to the child process stdin and reading from its
stdout. I am going to use it later for testing
On Fri, Feb 14, 2014 at 3:24 PM, bearophile bearophileh...@lycos.com wrote:
Meta:
While it is heavier than Haskell's syntax, I have been consistently and
pleasantly surprised by how powerful D's template pattern matching is (bugs
notwithstanding). I wonder how well-known this is outside this
Just a quick look, but I betcha it has to do with buffering.
After writing the line to the pipe, call the flush() method on
the output pipe and see what happens there.
(Pipes buffer differently than regular output so this is a common
mixup, especially with IDEs which communicate with stdout
On Friday, 14 February 2014 at 19:05:02 UTC, Thomas wrote:
I'm new to D, and I find it quite enjoyable so far.
I have however stumbled upon a problem which I can't seem to
figure out.
I am trying to make a program that creates a child process,
writes something to the child process stdin and
On Fri, 14 Feb 2014 14:05:01 -0500, Thomas sitronv...@gmail.com wrote:
I'm new to D, and I find it quite enjoyable so far.
I have however stumbled upon a problem which I can't seem to
figure out.
I am trying to make a program that creates a child process,
writes something to the child process
On Friday, 14 February 2014 at 19:09:06 UTC, nazriel wrote:
On Friday, 14 February 2014 at 19:05:02 UTC, Thomas wrote:
I'm new to D, and I find it quite enjoyable so far.
I have however stumbled upon a problem which I can't seem to
figure out.
I am trying to make a program that creates a child
On Friday, 14 February 2014 at 19:08:20 UTC, Adam D. Ruppe wrote:
Just a quick look, but I betcha it has to do with buffering.
After writing the line to the pipe, call the flush() method on
the output pipe and see what happens there.
(Pipes buffer differently than regular output so this is a
On Fri, 14 Feb 2014 14:16:23 -0500, Thomas sitronv...@gmail.com wrote:
On Friday, 14 February 2014 at 19:08:20 UTC, Adam D. Ruppe wrote:
Just a quick look, but I betcha it has to do with buffering. After
writing the line to the pipe, call the flush() method on the output
pipe and see what
On Friday, 14 February 2014 at 19:12:24 UTC, Steven Schveighoffer
wrote:
On Fri, 14 Feb 2014 14:05:01 -0500, Thomas
sitronv...@gmail.com wrote:
I'm new to D, and I find it quite enjoyable so far.
I have however stumbled upon a problem which I can't seem to
figure out.
I am trying to make a
I recently downloaded and tried to use DGUI but I can't get it to
work. Is there any tutorials on how to build an use it? Or can
anyone help me and tel me a way on how I can get it to work?
On Friday, 14 February 2014 at 20:29:50 UTC, Josh Phillips wrote:
I recently downloaded and tried to use DGUI but I can't get it
to work. Is there any tutorials on how to build an use it? Or
can anyone help me and tel me a way on how I can get it to work?
Unless I am mistaken, it looks like
On Friday, 14 February 2014 at 17:42:53 UTC, bearophile wrote:
Isn't this discussion about adding an index to a range? If it
is, then I have shown why adding it in the language is a bad
idea.
As far as I understand it, it's about adding an index to
_foreach_, as is already supported for
On Thursday, February 13, 2014 23:37:13 Timothee Cour wrote:
Is there a function to do this?
If not and I/someone writes it, is there interest to add it to std.datetime?
Duration t = ...;
t.to!string = 5 secs, 889 ms, and 811 μs
t.round.to!string= 5 secs
t=...;
t.to!string = 889 ms,
On 2/14/2014 11:00 AM, Robin wrote:
class Matrix(T = double) {
private T[] data;
private Dimension dim;
}
A matrix is just plain-old-data, so use a struct, you don't need a class.
A struct will be much more lightweight: A struct doesn't normally
involve memory allocations like a
Nick Sabalausky:
T opIndex(size_t row, size_t col) const {
immutable size_t i = this.dim.offset(row, col);
if (i = this.dim.size) {
// TODO - have to learn exception handling in D first.
:P
}
return this.data[i];
}
No need for the bounds check. D already does bounds
Marc Schütz:
As far as I understand it, it's about adding an index to
_foreach_, as is already supported for arrays:
foreach(v; [1,2,3,4])
writeln(v);
foreach(i, v; [1,2,3,4])
writeln(i, = , v);
But for ranges, the second form is not possible:
foreach(v; iota(4)) // ok
thanks!
On Fri, Feb 14, 2014 at 2:14 PM, Jonathan M Davis jmdavisp...@gmx.comwrote:
On Thursday, February 13, 2014 23:37:13 Timothee Cour wrote:
Is there a function to do this?
If not and I/someone writes it, is there interest to add it to
std.datetime?
Duration t = ...;
t.to!string
I seem to be having some difficulty with the nan and init
properties of floating point types. Can anyone explain why the
following assertions all fail:
assert(float.init == float.nan);
assert(float.nan == float.nan);
assert(float.init == float.init);
Thanks.
On Saturday, 15 February 2014 at 05:18:51 UTC, Adam S wrote:
assert(float.init == float.nan);
nan never equals nan, this is in the floating point spec used by
D, C and others.
Use this instead:
http://dlang.org/phobos/std_math.html#isNaN
Adam D. Ruppe:
nan never equals nan,
Additionally, the init NaN doesn't have the same bitpattern as
the other. There are many NaNs.
Bye,
bearophile
Also I have the following code but I get some error. I think it's
because of std.algorithm.sort function that uses mixin to inject
predcate. But it doesn't import symbols passed in predicate and
fails. Is there some way of resolving this problem or I need to
inject full code of function inside
I solved it myself. I forget that I can use function as predicate
import std.stdio, std.algorithm;
class A: Exception { this(){ super(null); } }
class B: A {}
class C: B {}
class D: A {}
class E: A {}
class F: E {}
size_t countDerivations(TypeInfo_Class typeinfo)
{
size_t
46 matches
Mail list logo
