fixwhitespace - fixes what dmd complains about

fixwhitespace.d

/**
 * License:     $(LINK2 http://www.boost.org/LICENSE_1_0.txt, Boost License 1.0)
 * Source:      $(DMDSRC _checkwhitespace.d)
 */


import std.stdio : writefln;
import std.file;
import std.string;
import std.range;
import std.regex;
import std.algorithm;
import std.path;

int main(string[] args)
{
    bool error;
	uint checks;
    auto r = regex(r" +\n");
    foreach(a; args[1..$])
    {
        try
        {
            uint line = 1;
            ptrdiff_t pos;
            auto str = a.readText();
            char[] wFile;
            ptrdiff_t lastpos;
            wFile.reserve(str.length);
            while(str.length) {
            if ((pos = str.indexOf("\r\n")) >= 0)
            {
				if (lastpos == pos) break;
				lastpos = pos;
                line += str[0..pos].count('\n');
                writefln("Info - file '%s' did contain windows line endings at line %d", a,  line);
                error = true;
                wFile ~= str[0 .. pos];
                wFile ~= "\n";
                str = str[pos+2 .. $];
				continue;
            }
            if (a.extension() != ".mak" && (pos = str.indexOf('\t')) >= 0)
            {
				if (lastpos == pos) break;
				lastpos = pos;
                line += str[0..pos].count('\n');
                writefln("Info - file '%s' did contain tabs at line %d", a, line);
                error = true;
				
                wFile ~= str[0 .. pos] ~ "    ";
				str = str[pos+1 .. $];
				while(str[0] == '\t') {wFile ~= "    "; str = str[1 .. $];}
				continue;
            }
            auto m = str.matchFirst(r);
            if (!m.empty)
            {
                pos = m.front.ptr - str.ptr; // assume the match is a slice of the string
				if (lastpos == pos) break;
				lastpos = pos;
                line += str[0..pos].count('\n');
                writefln("Info - file '%s' did contain trailing whitespace at line %d", a, line);
                wFile ~= str[0 .. pos];
                str = str[pos + m.front.length-1 .. $];
                error = true;
				continue;
            }
			
			if (checks++ == 3) break;
			}
            wFile ~= str[0 .. $];
            str = str[$ .. $];
            
            a.write(wFile);
        }
        catch(Exception e)
        {
            writefln("Exception - file '%s': %s", a, e.msg);
        }
    }
    return error ? 1 : 0;
}