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-rw-r--r--lib/std/mem.zig165
1 files changed, 146 insertions, 19 deletions
diff --git a/lib/std/mem.zig b/lib/std/mem.zig
index 046339b6fc..f54610f060 100644
--- a/lib/std/mem.zig
+++ b/lib/std/mem.zig
@@ -1707,23 +1707,32 @@ pub fn split(comptime T: type, buffer: []const T, delimiter: []const T) SplitIte
test "split" {
var it = split(u8, "abc|def||ghi", "|");
- try testing.expect(eql(u8, it.next().?, "abc"));
- try testing.expect(eql(u8, it.next().?, "def"));
- try testing.expect(eql(u8, it.next().?, ""));
- try testing.expect(eql(u8, it.next().?, "ghi"));
+ try testing.expectEqualSlices(u8, it.rest(), "abc|def||ghi");
+ try testing.expectEqualSlices(u8, it.next().?, "abc");
+
+ try testing.expectEqualSlices(u8, it.rest(), "def||ghi");
+ try testing.expectEqualSlices(u8, it.next().?, "def");
+
+ try testing.expectEqualSlices(u8, it.rest(), "|ghi");
+ try testing.expectEqualSlices(u8, it.next().?, "");
+
+ try testing.expectEqualSlices(u8, it.rest(), "ghi");
+ try testing.expectEqualSlices(u8, it.next().?, "ghi");
+
+ try testing.expectEqualSlices(u8, it.rest(), "");
try testing.expect(it.next() == null);
it = split(u8, "", "|");
- try testing.expect(eql(u8, it.next().?, ""));
+ try testing.expectEqualSlices(u8, it.next().?, "");
try testing.expect(it.next() == null);
it = split(u8, "|", "|");
- try testing.expect(eql(u8, it.next().?, ""));
- try testing.expect(eql(u8, it.next().?, ""));
+ try testing.expectEqualSlices(u8, it.next().?, "");
+ try testing.expectEqualSlices(u8, it.next().?, "");
try testing.expect(it.next() == null);
it = split(u8, "hello", " ");
- try testing.expect(eql(u8, it.next().?, "hello"));
+ try testing.expectEqualSlices(u8, it.next().?, "hello");
try testing.expect(it.next() == null);
var it16 = split(
@@ -1731,17 +1740,18 @@ test "split" {
std.unicode.utf8ToUtf16LeStringLiteral("hello"),
std.unicode.utf8ToUtf16LeStringLiteral(" "),
);
- try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("hello")));
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("hello"));
try testing.expect(it16.next() == null);
}
test "split (multibyte)" {
var it = split(u8, "a, b ,, c, d, e", ", ");
- try testing.expect(eql(u8, it.next().?, "a"));
- try testing.expect(eql(u8, it.next().?, "b ,"));
- try testing.expect(eql(u8, it.next().?, "c"));
- try testing.expect(eql(u8, it.next().?, "d"));
- try testing.expect(eql(u8, it.next().?, "e"));
+ try testing.expectEqualSlices(u8, it.next().?, "a");
+ try testing.expectEqualSlices(u8, it.rest(), "b ,, c, d, e");
+ try testing.expectEqualSlices(u8, it.next().?, "b ,");
+ try testing.expectEqualSlices(u8, it.next().?, "c");
+ try testing.expectEqualSlices(u8, it.next().?, "d");
+ try testing.expectEqualSlices(u8, it.next().?, "e");
try testing.expect(it.next() == null);
var it16 = split(
@@ -1749,11 +1759,99 @@ test "split (multibyte)" {
std.unicode.utf8ToUtf16LeStringLiteral("a, b ,, c, d, e"),
std.unicode.utf8ToUtf16LeStringLiteral(", "),
);
- try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("a")));
- try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b ,")));
- try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c")));
- try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d")));
- try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("e")));
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("a"));
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b ,"));
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c"));
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d"));
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("e"));
+ try testing.expect(it16.next() == null);
+}
+
+/// Returns an iterator that iterates backwards over the slices of `buffer`
+/// that are separated by bytes in `delimiter`.
+/// splitBackwards(u8, "abc|def||ghi", "|")
+/// will return slices for "ghi", "", "def", "abc", null, in that order.
+/// If `delimiter` does not exist in buffer,
+/// the iterator will return `buffer`, null, in that order.
+/// The delimiter length must not be zero.
+pub fn splitBackwards(comptime T: type, buffer: []const T, delimiter: []const T) SplitBackwardsIterator(T) {
+ assert(delimiter.len != 0);
+ return SplitBackwardsIterator(T){
+ .index = buffer.len,
+ .buffer = buffer,
+ .delimiter = delimiter,
+ };
+}
+
+test "splitBackwards" {
+ var it = splitBackwards(u8, "abc|def||ghi", "|");
+ try testing.expectEqualSlices(u8, it.rest(), "abc|def||ghi");
+ try testing.expectEqualSlices(u8, it.next().?, "ghi");
+
+ try testing.expectEqualSlices(u8, it.rest(), "abc|def|");
+ try testing.expectEqualSlices(u8, it.next().?, "");
+
+ try testing.expectEqualSlices(u8, it.rest(), "abc|def");
+ try testing.expectEqualSlices(u8, it.next().?, "def");
+
+ try testing.expectEqualSlices(u8, it.rest(), "abc");
+ try testing.expectEqualSlices(u8, it.next().?, "abc");
+
+ try testing.expectEqualSlices(u8, it.rest(), "");
+ try testing.expect(it.next() == null);
+
+ it = splitBackwards(u8, "", "|");
+ try testing.expectEqualSlices(u8, it.next().?, "");
+ try testing.expect(it.next() == null);
+
+ it = splitBackwards(u8, "|", "|");
+ try testing.expectEqualSlices(u8, it.next().?, "");
+ try testing.expectEqualSlices(u8, it.next().?, "");
+ try testing.expect(it.next() == null);
+
+ it = splitBackwards(u8, "hello", " ");
+ try testing.expectEqualSlices(u8, it.next().?, "hello");
+ try testing.expect(it.next() == null);
+
+ var it16 = splitBackwards(
+ u16,
+ std.unicode.utf8ToUtf16LeStringLiteral("hello"),
+ std.unicode.utf8ToUtf16LeStringLiteral(" "),
+ );
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("hello"));
+ try testing.expect(it16.next() == null);
+}
+
+test "splitBackwards (multibyte)" {
+ var it = splitBackwards(u8, "a, b ,, c, d, e", ", ");
+ try testing.expectEqualSlices(u8, it.rest(), "a, b ,, c, d, e");
+ try testing.expectEqualSlices(u8, it.next().?, "e");
+
+ try testing.expectEqualSlices(u8, it.rest(), "a, b ,, c, d");
+ try testing.expectEqualSlices(u8, it.next().?, "d");
+
+ try testing.expectEqualSlices(u8, it.rest(), "a, b ,, c");
+ try testing.expectEqualSlices(u8, it.next().?, "c");
+
+ try testing.expectEqualSlices(u8, it.rest(), "a, b ,");
+ try testing.expectEqualSlices(u8, it.next().?, "b ,");
+
+ try testing.expectEqualSlices(u8, it.rest(), "a");
+ try testing.expectEqualSlices(u8, it.next().?, "a");
+
+ try testing.expectEqualSlices(u8, it.rest(), "");
+ try testing.expect(it.next() == null);
+
+ var it16 = splitBackwards(
+ u16,
+ std.unicode.utf8ToUtf16LeStringLiteral("a, b ,, c, d, e"),
+ std.unicode.utf8ToUtf16LeStringLiteral(", "),
+ );
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("e"));
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d"));
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c"));
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b ,"));
+ try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("a"));
try testing.expect(it16.next() == null);
}
@@ -1862,6 +1960,35 @@ pub fn SplitIterator(comptime T: type) type {
};
}
+pub fn SplitBackwardsIterator(comptime T: type) type {
+ return struct {
+ buffer: []const T,
+ index: ?usize,
+ delimiter: []const T,
+
+ const Self = @This();
+
+ /// Returns a slice of the next field, or null if splitting is complete.
+ pub fn next(self: *Self) ?[]const T {
+ const end = self.index orelse return null;
+ const start = if (lastIndexOf(T, self.buffer[0..end], self.delimiter)) |delim_start| blk: {
+ self.index = delim_start;
+ break :blk delim_start + self.delimiter.len;
+ } else blk: {
+ self.index = null;
+ break :blk 0;
+ };
+ return self.buffer[start..end];
+ }
+
+ /// Returns a slice of the remaining bytes. Does not affect iterator state.
+ pub fn rest(self: Self) []const T {
+ const end = self.index orelse 0;
+ return self.buffer[0..end];
+ }
+ };
+}
+
/// Naively combines a series of slices with a separator.
/// Allocates memory for the result, which must be freed by the caller.
pub fn join(allocator: Allocator, separator: []const u8, slices: []const []const u8) ![]u8 {
generated by cgit v1.2.3 (git 2.39.1) at 2025-12-28 02:59:32 +0000