Why can't the compiler properly detect the type of Array!string("something")?
Adnan
relay.public.adnan at outlook.com
Sat Mar 14 23:45:24 UTC 2020
On Saturday, 14 March 2020 at 23:39:11 UTC, Adnan wrote:
> In the following code the compiler says the type is
> Array!()(string):
>
> if (key in wordTable)
> wordTable[key] ~= word;
> else
> wordTable[key] = Array!string(word);
>
>
> source/app.d(29,36): Error: template
> std.container.array.Array!string.Array.__ctor cannot deduce
> functi
> on from argument types !()(string), candidates are:
> /snap/dmd/99/bin/../import/phobos/std/container/array.d(467,5):
> __ctor(U)(U[] values...)
> with U = immutable(char)
> must satisfy the following constraint:
> isImplicitlyConvertible!(U, T)
> /snap/dmd/99/bin/../import/phobos/std/container/array.d(501,5):
> __ctor(Range)(Range r)
> with Range = string
> must satisfy the following constraint:
> isImplicitlyConvertible!(ElementType!Range, T)
Full code
string smallestRepr(const string arg) {
auto repeated = arg ~ arg;
string result = arg;
foreach (i; 1 .. arg.length) {
const slice = repeated[i .. i + arg.length];
if (slice < result)
result = slice;
}
return result;
}
unittest {
assert("cba".smallestRepr() == "acb");
}
void main(const string[] args) {
import std.stdio : write, File;
import std.container : Array;
Array!string[string] wordTable;
foreach (string word; File(args[1]).byLineCopy()) {
word = word[0 .. $ - 1]; // strip the newline character
const string key = word.smallestRepr();
debug {
if (key in wordTable)
wordTable[key] ~= word;
else
wordTable[key] = Array!string(word);
}
else {
wordTable.require(key, Array!string()) ~= word;
}
}
foreach (array; wordTable.values) {
if (array.length == 4) {
foreach (word; array) {
write(word, ", ");
}
write("\n");
break;
}
}
}
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