Convert strings with different format to float

[Pelle]

On 09/08/2010 09:23 AM, Tom Kazimiers wrote:
> Hi,
>
> I try to read data in from a file. This data consist mainly of numbers
> and I have a hard time converting it to number type variables. Two data
> lines could look like this
>
> v 0 0 0
> v 1.5 1.2 0
>
> Now I want to parse those lines and call a method, the line in passed
> (as char[]) to it:
>
> int index = indexOf(line, "v ");
> if(index != -1) {
>      vc++;
>      float x = 0.0, y = 0.0, z = 0.0;
>      char[][] vertexCoords = split( line[index+2 .. $] );
>
>      if (vertexCoords.length>  0)
>          x = to!int(vertexCoords[0]);
>      if (vertexCoords.length>  1)
>          y = to!int(vertexCoords[1]);
>      if (vertexCoords.length>  2)
>          z = to!int(vertexCoords[2]);
>
>      process_vertex(vc,x,y,z);
>      return;
> }
>
> First I split the remaining characters (after "v ") into parts (here is
> probably dynamic copying included?). Then I want to convert each part to
> a float value.
>
> The problem I have is that I obviously need to use "to!int" for numbers
> with out decimal point and "to!float" for numbers with. But since those
> can be mixed I would ask for every part if there is a decimal point, e.g:
>
> if (vertexCoords.length>  0) {
> 	if (indexOf(vertexCoords[0], ".") != -1)
> 	        x = to!float(vertexCoords[0]);
> 	else
> 		x = to!int(vertexCoords[0]);
> }
>
> Is there a more convient way to achieve that? I am coming from C++ and
> IIRC one could do there sth. like this:
>
> int index = line.find("v ");
> if(index != std::string::npos) {
>      line.erase(0,index+1);
>      vc++;
>      float x,y,z = 0;
>
>      std::istringstream ins;
>      ins.str(line);
>      ins>>  x>>  y>>  z;
>
>      process_vertex(vc,x,y,z);
>      return;
> }
>
> That looks much cleaner to me (besides the ">>" operators). So I am
> looking for sth. similar in D :-). Maybe a to!float that can cope with
> numbers without decimal point.
>
> Cheers,
> Tom

You seem to have found a bug in to!float :-)

to!float("123") works as expected, but to!float("0") bugs out. Huh!