[Issue 8729] parse!bool does not work correctly

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=8729



--- Comment #2 from monarchdodra at gmail.com 2012-09-26 13:52:15 PDT ---
(In reply to comment #1)
> (In reply to comment #0)
> > This code
> > 
> > import std.conv;
> > import std.stdio;
> > 
> > void main()
> > {
> >     auto str = "123 456.7 false";
> > 
> >     auto i = parse!int(str);
> >     auto d = parse!double(str);
> >     auto b = parse!bool(str);
> > 
> >     assert(i == 123);
> >     assert(d == 456.7);
> >     assert(b == false);
> > }
> > 
> > results in this exception when you run it
> > 
> > std.conv.ConvException at std/conv.d(2654): Can't parse string: bool should be
> > case-insensive 'true' or 'false'
> > ----------------
> > ./q(bool std.conv.parse!(bool, immutable(char)[]).parse(ref
> > immutable(char)[])+0x183) [0x43867b]
> > ./q(_Dmain+0x42) [0x430ec2]
> > ./q(extern (C) int rt.dmain2.main(int, char**).void runMain()+0x1c) [0x43b240]
> > ./q(extern (C) int rt.dmain2.main(int, char**).void tryExec(scope void
> > delegate())+0x2a) [0x43abba]
> > ./q(extern (C) int rt.dmain2.main(int, char**).void runAll()+0x3b) [0x43b287]
> > ./q(extern (C) int rt.dmain2.main(int, char**).void tryExec(scope void
> > delegate())+0x2a) [0x43abba]
> > ./q(main+0xd1) [0x43ab45]
> > /usr/lib/libc.so.6(__libc_start_main+0xf5) [0x7fd238fc1725]
> > ----------------
> > 
> > If you change it to
> > 
> > import std.conv;
> > import std.stdio;
> > 
> > void main()
> > {
> >     auto str = "false 123 456.7";
> > 
> >     auto b = parse!bool(str);
> >     auto i = parse!int(str);
> >     auto d = parse!double(str);
> > 
> >     assert(i == 123);
> >     assert(d == 456.7);
> >     assert(b == false);
> > }
> > 
> > you get
> > 
> > std.conv.ConvException at std/conv.d(1771): Unexpected ' ' when converting from
> > type string to type int
> > ----------------
> > ./q(int std.conv.parse!(int, immutable(char)[]).parse(ref
> > immutable(char)[])+0x1b8) [0x431984]
> > ./q(_Dmain+0x33) [0x430eb3]
> > ./q(extern (C) int rt.dmain2.main(int, char**).void runMain()+0x1c) [0x43b240]
> > ./q(extern (C) int rt.dmain2.main(int, char**).void tryExec(scope void
> > delegate())+0x2a) [0x43abba]
> > ./q(extern (C) int rt.dmain2.main(int, char**).void runAll()+0x3b) [0x43b287]
> > ./q(extern (C) int rt.dmain2.main(int, char**).void tryExec(scope void
> > delegate())+0x2a) [0x43abba]
> > ./q(main+0xd1) [0x43ab45]
> > /usr/lib/libc.so.6(__libc_start_main+0xf5) [0x7f1286cc0725]
> > ----------------
> > 
> > Just parsing out bool when it's first and then parsing _nothing_ else works,
> > but it seems like parsing it under any other circumstances fails (from what I
> > can tell anyway).
> 
> Sounds like the implementation is looking for a literal "true" or "false", and
> is forgetting to skip leading ws.
> 
> [SNIP]

Bigtime!

// string to bool conversions
Target parse(Target, Source)(ref Source s)
    if (isSomeString!Source && !is(Source == enum) &&
        is(Unqual!Target == bool))
{
    if (s.length >= 4 && icmp(s[0 .. 4], "true")==0)
    {
        s = s[4 .. $];
        return true;
    }
    if (s.length >= 5 && icmp(s[0 .. 5], "false")==0)
    {
        s = s[5 .. $];
        return false;
    }
    parseError("bool should be case-insensive 'true' or 'false'");
    assert(0);
}

I got this.

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------