On 06/23/2012 02:17 PM, simendsjo wrote:
On Sat, 23 Jun 2012 19:52:32 +0200, Chad J
<chadjoan@__spam.is.bad__gmail.com> wrote:
As an additional note: I could probably do this easily if I had a
function like findSplit where the predicate is used /instead/ of a
delimiter. So like this:
auto findSplit(alias pred = "a", R)(R haystack);
...
auto tuple = findSplit!(`a == "\n" || a == "\r\n" || a == "\r"`)(text);
return tuple[2];
I don't think it can match on ranges, but it's pretty trivial to
implement something that would work for your case
import std.array, std.algorithm, std.typecons;
auto newlineSplit(string data) {
auto rest = data.findAmong("\r\n");
if(!rest.empty) { // found
auto pre = data[0..data.length-rest.length];
string match;
if(rest.front == '\r' && (rest.length > 1 && rest[1] == '\n')) { // \r\n
match = rest[0..2];
rest = rest[2..$];
} else { // \r or \n
match = rest[0..1];
rest = rest[1..$];
}
return tuple(pre, match, rest);
} else {
return tuple(data, "", "");
}
}
unittest {
auto text = "1\n2\r\n3\r4";
auto res = text.newlineSplit();
assert(res[0] == "1");
assert(res[1] == "\n");
assert(res[2] == "2\r\n3\r4");
res = res[2].newlineSplit();
assert(res[0] == "2");
assert(res[1] == "\r\n");
assert(res[2] == "3\r4");
res = res[2].newlineSplit();
assert(res[0] == "3");
assert(res[1] == "\r");
assert(res[2] == "4");
res = res[2].newlineSplit();
assert(res[0] == "4");
assert(res[1] == "");
assert(res[2] == "");
}
Hey, thanks for doing all of that. I didn't expect you to write all of
that.
Once I've established that the issue isn't just a lack of learning on my
part, my subsequent objective is filling any missing functionality in
phobos. IMO the "take away a single line" thing should be
accomplishable with a single concise expression. Then there should be a
function in std.string that contains that single expression and wraps it
in easy-to-find documentation. This kind of thing is a fairly common
operation. Otherwise, I find it odd that there is a function to split
up an arbitrary number of lines but no function to split off only one!
Also, any function that works with whitespace should have
versions/variants that work with arbitrary delimiters. Not unless it is
impossible to generalize it that way for some reason. If the variants
are found in a separate module, then the documentation should reference
them.
