Function std.uni.MatcherConcept.test

The effect on inp depends on the kind of function called:

Match. If the codepoint is found in the set then range inp is advanced by its size in Code unit, code units, otherwise the range is not modifed.

Skip. The range is always advanced by the size of the tested regardless of the result of test.

Test. The range is left unaffected regardless of the result of test.

Prototype

bool test(Range)(
  Range inp
)
if (isRandomAccessRange!Range && is(ElementType!Range : char));

Example

string truth = "2² = 4";
auto m = utfMatcher!char(unicode.Number);
assert(m.match(truth)); // '2' is a number all right
assert(truth == "² = 4"); // skips on match
assert(m.match(truth)); // so is the superscript '2'
assert(!m.match(truth)); // space is not a number
assert(truth == " = 4"); // unaffected on no match
assert(!m.skip(truth)); // same test ...
assert(truth == "= 4"); // but skips a codepoint regardless
assert(!m.test(truth)); // '=' is not a number
assert(truth == "= 4"); // test never affects argument

Example

auto m = utfMatcher!char(unicode.Number);
string square = "2²";
// about sub-matchers
assert(!m.subMatcher!(2,3,4).test(square)); // ASCII no covered
assert(m.subMatcher!1.match(square)); // ASCII-only, works
assert(!m.subMatcher!1.test(square)); // unicode '²'
assert(m.subMatcher!(2,3,4).match(square));  //
assert(square == "");
wstring wsquare = "2²";
auto m16 = utfMatcher!wchar(unicode.Number);
// may keep ref, but the orignal (m16) must be kept alive
auto bmp = m16.subMatcher!1;
assert(bmp.match(wsquare)); // Okay, in basic multilingual plan
assert(bmp.match(wsquare)); // And '²' too
}