On Friday, 28 October 2016 at 14:31:47 UTC, Chris wrote:
On Friday, 28 October 2016 at 13:50:24 UTC, Alfred Newman wrote:
It boils down to something like:
if (c in _accent)
return _accent[c];
else
return c;
Just a normal lambda (condition true) ? yes : no;
I'd recommend you to use Marc's approach, though.
What you basically do is you pass the logic on to `map` and `map`
applies it to each item in the range (cf. [1]):
map!(myLogic)(range);
or (more idiomatic)
range.map!(myLogic);
This is true of a lot of functions, or rather templates, in the
Phobos standard library, especially functions in std.algorithm
(like find [2], canFind, filter etc.). In this way, instead of
writing for-loops with if-else statements, you pass the logic to
be applied within the `!()`-part of the template.
// Filter the letter 'l'
auto result = "Hello, world!".filter!(a => a != 'l'); // returns
"Heo, word!"
However, what is returned is not a string. So this won't work:
`writeln("Result is " ~ result);`
// Error: incompatible types for (("Result is ") ~ (result)):
'string' and
// 'FilterResult!(__lambda2, string)'
It returns a `FilterResult`.
To fix this, you can either write:
`
import std.conv;
auto result = "Hello, world!".filter!(a => a != 'l').to!string;
`
which converts it into a string.
or you do this:
`
import std.array;
auto result = "Hello, world!".filter!(a => a != 'l').array;
`
Then you have a string again and
`
writeln("Result is " ~ result);
`
works.
Just bear that in mind, because you will get the above error
sometimes. Marc's example is idiomatic D and you should become
familiar with it asap.
void main()
{
auto str = "très élégant";
immutable accents = unicode.Diacritic;
auto removed = str
// normalize each character
.normalize!NFD
// replace each diacritic with its non-diacritic
counterpart
.filter!(c => !accents[c])
// convert each item in FilterResult back to string.
.to!string;
writeln(removed); // prints "tres elegant"
}
[1] http://dlang.org/phobos/std_algorithm_iteration.html#.map
[1] http://dlang.org/phobos/std_algorithm_searching.html#.find
