On 6/10/22 4:33 PM, Antonio wrote:
When mapping and filtering, the last mapped element is evaluated
twice... Is it the expected behaviour?
```d
void main()
{
import std.algorithm, std.stdio;
[1,2,3,4,5].
map!((x){
writeln("mapping ", x);
return x;
}).
filter!(x=>x>2).
front.
writeln();
}
```
Output
```
mapping 1
mapping 2
mapping 3
mapping 3
3
```
`map` calls the lambda for each call to `front`. If you want a cached
version, use `cache`:
```d
void main()
{
import std.algorithm, std.stdio;
[1,2,3,4,5].
map!((x){
writeln("mapping ", x);
return x;
}).
cache.
filter!(x=>x>2).
front.
writeln();
}
```
-Steve
