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@safe unittest
{
import std.format;
// Easiest way is to use `%s` everywhere:
assert(format("I got %s %s for %s euros.", 30, "eggs", 5.27) == "I got 30 eggs for 5.27 euros.");
// Other format characters provide more control:
assert(format("I got %b %(%X%) for %f euros.", 30, "eggs", 5.27) == "I got 11110 65676773 for 5.270000 euros.");
}
@safe unittest
{
import std.format;
/*
The trailing end of the sub-format string following the specifier for
each item is interpreted as the array delimiter, and is therefore
omitted following the last array item:
*/
assert(format("My items are %(%s %).", [1,2,3]) == "My items are 1 2 3.");
assert(format("My items are %(%s, %).", [1,2,3]) == "My items are 1, 2, 3.");
/*
The "%|" delimiter specifier may be used to indicate where the
delimiter begins, so that the portion of the format string prior to
it will be retained in the last array element:
*/
assert(format("My items are %(-%s-%|, %).", [1,2,3]) == "My items are -1-, -2-, -3-.");
/*
These compound format specifiers may be nested in the case of a
nested array argument:
*/
auto mat = [[1, 2, 3],
[4, 5, 6],
[7, 8, 9]];
assert(format("%(%(%d %) - %)", mat), "1 2 3 - 4 5 6 - 7 8 9");
assert(format("[%(%(%d %) - %)]", mat), "[1 2 3 - 4 5 6 - 7 8 9]");
assert(format("[%([%(%d %)]%| - %)]", mat), "[1 2 3] - [4 5 6] - [7 8 9]");
/*
Strings and characters are escaped automatically inside compound
format specifiers. To avoid this behavior, use "%-(" instead of "%(":
*/
assert(format("My friends are %s.", ["John", "Nancy"]) == `My friends are ["John", "Nancy"].`);
assert(format("My friends are %(%s, %).", ["John", "Nancy"]) == `My friends are "John", "Nancy".`);
assert(format("My friends are %-(%s, %).", ["John", "Nancy"]) == `My friends are John, Nancy.`);
}
@safe unittest
{
import std.format;
// Flags can be used to influence to outcome:
assert(format("%g != %+#g", 3.14, 3.14) == "3.14 != +3.14000");
// Width and precision help to arrange the formatted result:
assert(format(">%10.2f<", 1234.56789) == "> 1234.57<");
// Numbers can be grouped:
assert(format("%,4d", int.max) == "21,4748,3647");
// It's possible to specify the position of an argument:
assert(format("%3$s %1$s", 3, 17, 5) == "5 3");
}
@safe unittest
{
import std.format;
// Width as argument
assert(format(">%*s<", 10, "abc") == "> abc<");
// Precision as argument
assert(format(">%.*f<", 5, 123.2) == ">123.20000<");
// Grouping as argument
assert(format("%,*d", 1, int.max) == "2,1,4,7,4,8,3,6,4,7");
// Grouping separator as argument
assert(format("%,3?d", '_', int.max) == "2_147_483_647");
// All at once
assert(format("%*.*,*?d", 20, 15, 6, '/', int.max) == " 000/002147/483647");
}
@safe unittest
{
import std.format;
import std.exception : assertThrown;
assertThrown!FormatException(format("%d", "foo"));
}
@safe pure unittest
{
import std.format;
assert(format("Here are %d %s.", 3, "apples") == "Here are 3 apples.");
assert("Increase: %7.2f %%".format(17.4285) == "Increase: 17.43 %");
}
@safe pure unittest
{
import std.format;
auto s = format!"%s is %s"("Pi", 3.14);
assert(s == "Pi is 3.14");
// This line doesn't compile, because 3.14 cannot be formatted with %d:
// s = format!"%s is %d"("Pi", 3.14);
}
@safe pure unittest
{
import std.format;
char[20] buf;
assert(sformat(buf[], "Here are %d %s.", 3, "apples") == "Here are 3 apples.");
assert(buf[].sformat("Increase: %7.2f %%", 17.4285) == "Increase: 17.43 %");
}
@safe pure unittest
{
import std.format;
char[20] buf;
assert(sformat!"Here are %d %s."(buf[], 3, "apples") == "Here are 3 apples.");
// This line doesn't compile, because 3.14 cannot be formatted with %d:
// writeln(sformat!"Here are %d %s."(buf[], 3.14, "apples"));
}
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