How to Humanize Numerical Input|Output

[Steven Schveighoffer]

On Monday, 9 September 2024 at 20:02:48 UTC, Jabari Zakiya wrote:
> I have this code to input integer values:
>
> ```
>   ulong[] x;
>   foreach (_; 0 .. 2) { ulong a; readf!" %d"(a); x ~= a; }
>   end_num = max(x[0], 3);
>   start_num = max(x[1], 3);
>   if (start_num > end_num) swap(start_num, end_num);
>   start_num = start_num | 1;             // if start_num even 
> add 1
>   end_num = (end_num - 1) | 1;           // if end_num even 
> subtract 1
>   if (end_num - start_num < 2) { start_num = 7; end_num = 7; }
>
> ```
>
> Currently I have to enter data as:   123456 789102
>
> I'd like to enter data as:  123_456 789_10
>
> How do I do that?
>
> Also for output, I do this:
>
> ```
> writeln("total twins = ", twinscnt, "; last twin = ", last_twin 
> - 1, "+/-1");
> ```
>
> I'd also like to output data as:  123,987 or 123_987

Given that you are just removing separators, just filter those 
out from your inputs.

Just get the raw text as a string, and use `formattedRead` with 
an appropriate filtering range to get what you want.

Something like

```d
import std.string;
import std.algorithm;
import std.format;
import std.stdio;
auto str = readln(); // get the line
auto filtered = str.filter!(c => "_,".indexOf(c) == -1); // 
filter out separators
ulong[] x;
foreach(_; 0 .. 2) {ulong a; filtered.formattedRead(" %d", a); x 
~= a; }
```

And I'd also recommend trying out range chaining:

```d
ulong[] x = str
     .filter!(c => "_,".indexOf(c) == -1)
     .splitter
     .map!(s => s.to!ulong)
     .array;
```

-Steve