Convert strings with different format to float

[Don]

Pelle wrote:
> 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!

Yes, it's a shocking bug. It's been fixed in svn for a couple of weeks, 
but we haven't made a release yet.