Re: Choosing between enum arrays or AliasSeqs
On Friday, 25 August 2017 at 08:27:41 UTC, Jacob Carlborg wrote:
Since you're converting the returned index to a bool, can't you
use "canFind" instead?
immutable englishIndefiniteArticles = [`a`, `an`];
bool isEnglishIndefiniteArticle(S)(S s)
{
return englishIndefiniteArticles.canFind(s);
}
`s.canFind` has time-complexity O(s.length)
Opposite to the template-parameter overload of `among` which has
O(1), making all the difference performance-wise in my case.
Re: Choosing between enum arrays or AliasSeqs
On 2017-08-25 08:12, Nordlöw wrote:
Thanks!
Your advice led to the following sample solution
import std.meta : aliasSeqOf;
immutable englishIndefiniteArticles = [`a`, `an`];
bool isEnglishIndefiniteArticle(S)(S s)
{
return cast(bool)s.among!(aliasSeqOf!englishIndefiniteArticles);
}
Is this the preferred way?
Since you're converting the returned index to a bool, can't you use
"canFind" instead?
immutable englishIndefiniteArticles = [`a`, `an`];
bool isEnglishIndefiniteArticle(S)(S s)
{
return englishIndefiniteArticles.canFind(s);
}
Could a template-parameter overload to `among` (perhaps calling it
something slighty different) be defined that takes an immutable array as
argument to prevent the conversion to the `AliasSeq` prior to the call?
I guess. Currently none of the existing overloads take an array,
immutable or otherwise. They expect the values to be give as separate
arguments.
--
/Jacob Carlborg
Re: Choosing between enum arrays or AliasSeqs
On Thursday, 24 August 2017 at 22:38:29 UTC, Meta wrote:
https://dlang.org/phobos/std_meta.html#aliasSeqOf
Thanks!
Your advice led to the following sample solution
import std.meta : aliasSeqOf;
immutable englishIndefiniteArticles = [`a`, `an`];
bool isEnglishIndefiniteArticle(S)(S s)
{
return
cast(bool)s.among!(aliasSeqOf!englishIndefiniteArticles);
}
Is this the preferred way?
Could a template-parameter overload to `among` (perhaps calling
it something slighty different) be defined that takes an
immutable array as argument to prevent the conversion to the
`AliasSeq` prior to the call?
More here:
https://github.com/nordlow/phobos-next/blob/c7d9a0f9c3280fc7852584ee2be387646a5f7857/src/grammar.d#L49
Re: Choosing between enum arrays or AliasSeqs
On Thursday, 24 August 2017 at 19:41:46 UTC, Nordlöw wrote:
Given
enum e = ['a', 'b', 'c'];
import std.meta : AliasSeq;
enum a = AliasSeq!['a', 'b', 'c'];
is it somehow possible to convert (at compile-time) `e` to `a`?
Is it cheaper CT-performance wise to use AliasSeq instead of
enum static arrays?
My use case is expressed by the TODOs in the following code
snippet
import std.algorithm : among;
/** English indefinite articles. */
enum englishIndefiniteArticles = [`a`, `an`];
/** English definite articles. */
enum englishDefiniteArticles = [`the`];
/** English definite articles. */
enum englishArticles = englishIndefiniteArticles ~
englishDefiniteArticles;
/** Check if $(D c) is a Vowel. */
bool isEnglishIndefiniteArticle(C)(C c)
if (isSomeChar!C)
{
return cast(bool)c.among!(`a`, `an`); // TODO reuse
englishIndefiniteArticles
}
/** Check if $(D c) is a Vowel. */
bool isEnglishDefiniteArticle(C)(C c)
if (isSomeChar!C)
{
return cast(bool)c.among!(`the`); // TODO reuse
englishDefiniteArticles
}
/** Check if $(D c) is a Vowel. */
bool isEnglishArticle(C)(C c)
if (isSomeChar!C)
{
return cast(bool)c.among!(`a`, `an`, `the`); // TODO reuse
englishArticles
}
https://dlang.org/phobos/std_meta.html#aliasSeqOf
Choosing between enum arrays or AliasSeqs
Given
enum e = ['a', 'b', 'c'];
import std.meta : AliasSeq;
enum a = AliasSeq!['a', 'b', 'c'];
is it somehow possible to convert (at compile-time) `e` to `a`?
Is it cheaper CT-performance wise to use AliasSeq instead of enum
static arrays?
My use case is expressed by the TODOs in the following code
snippet
import std.algorithm : among;
/** English indefinite articles. */
enum englishIndefiniteArticles = [`a`, `an`];
/** English definite articles. */
enum englishDefiniteArticles = [`the`];
/** English definite articles. */
enum englishArticles = englishIndefiniteArticles ~
englishDefiniteArticles;
/** Check if $(D c) is a Vowel. */
bool isEnglishIndefiniteArticle(C)(C c)
if (isSomeChar!C)
{
return cast(bool)c.among!(`a`, `an`); // TODO reuse
englishIndefiniteArticles
}
/** Check if $(D c) is a Vowel. */
bool isEnglishDefiniteArticle(C)(C c)
if (isSomeChar!C)
{
return cast(bool)c.among!(`the`); // TODO reuse
englishDefiniteArticles
}
/** Check if $(D c) is a Vowel. */
bool isEnglishArticle(C)(C c)
if (isSomeChar!C)
{
return cast(bool)c.among!(`a`, `an`, `the`); // TODO reuse
englishArticles
}
