I didn't notice the other parts of your post before.
On 12/09/2011 03:25 PM, Regan Heath wrote:
On Fri, 09 Dec 2011 13:42:34 -0000, Timon Gehr <timon.g...@gmx.ch> wrote:
On 12/09/2011 02:28 PM, Regan Heath wrote:
On Fri, 09 Dec 2011 13:15:47 -0000, Timon Gehr <timon.g...@gmx.ch>
wrote:
On 12/09/2011 01:36 PM, Regan Heath wrote:
4)
if (std.ascii.toLower(p.front) == 'n' &&
(p.popFront(), std.ascii.toLower(p.front) == 'f') &&
(p.popFront(), p.empty))
'if' statements with side effects are yuck. I prefer the check for
error
and bail style but you could use multiple layers of 'if' instead..
if (std.ascii.toLower(p.front) != 'n') //error handling
p.popFront();
if (std.ascii.toLower(p.front) != 'f') //error handling
p.popFront();
if (!p.empty) //error handling
Your '//error handling' shortcut hides relevant information.
What information? With context I could be more specific about what to do
for each/all.
You can always grep the Phobos source to get context. Basically, you
are suggesting to replace the comma operator with gotos:
case 'i': case 'I':
p.popFront();
if (std.ascii.toLower(p.front) == 'n' &&
(p.popFront(), std.ascii.toLower(p.front) == 'f') &&
(p.popFront(), p.empty))
{
// 'inf'
return sign ? -Target.infinity : Target.infinity;
}
goto default;
default: {}
}
If using 'goto' is the 'correct' agreed upon style for phobos then, yes.
It's not my personal preference however and I'd probably refactor it
further if it was my own code.
The code was probably written that way to give an optimal implementation
that does not use goto. How would you refactor the code?
5)
enforce((p.popFront(), !p.empty && std.ascii.toUpper(p.front) == 'A')
&& (p.popFront(), !p.empty && std.ascii.toUpper(p.front) == 'N'),
new ConvException("error converting input to floating point"));
This is blatant enforce abuse IMO..
p.popFront();
if(p.empty || std.ascii.toUpper(p.front) != 'A'))
throw new ConvException("error converting input to floating point"));
p.popFront();
if(p.empty || std.ascii.toUpper(p.front) != 'N'))
throw new ConvException("error converting input to floating point"));
This is blatant code duplication.
Of the throw line? Sure, and you can re-write with nested 'if' if you
prefer. I prefer the code duplication tho.
Code duplication is very error prone. Furthermore I never ever want to
duplicate _error handling_ code. That just clutters up the generated
machine code if the compiler does not manage to reverse engineer and
generate the proper solution.
I can't comment on the machine code aspect. I don't find this particular
duplication error prone, but if you do you can use the nested if that
I've already mentioned.
I don't like the nested if solution. Also it does not work that well in
the general case because you might have a || operator somewhere instead
of just && operators.
