Transforming

These return an owned string (they can't be expressed as a sub-range), so they allocate their result — but in a single pass directly from the view, with no intermediate copy.

concat

concat(other) joins the view with other (a string or a str).

str.from("foo").concat("bar"); // "foobar"
str.concat(str.slice("xxfoo", 2), "bar"); // "foobar"

The + operator does the same between two views, returning a view over the fresh string.

repeat

repeat(count) repeats the view count times.

str.from("ab").repeat(3); // "ababab"

padStart / padEnd

padStart(length, pad?) / padEnd(length, pad?) pad to length code units with pad (default " "), matching String#padStart / String#padEnd (the pad string is repeated and truncated to fit).

str.from("7").padStart(3, "0"); // "007"
str.from("7").padEnd(3, "0"); // "700"

These build the pad fill inline rather than calling the native op, which makes them faster than native.

replace / replaceAll

replace(search, replacement) replaces the first occurrence; replaceAll replaces every (non-overlapping, left-to-right) occurrence. Replacement is literal (no $ patterns), matching AssemblyScript's String.

str.from("a-b-c").replace("-", "+"); // "a+b-c"
str.from("a-b-c").replaceAll("-", "+"); // "a+b+c"

Both locate matches with the accelerated scan and assemble the result in one allocation — substantially faster than native, and correct where this asc version's String#replaceAll is not.

toUpperCase / toLowerCase

Full-Unicode case mapping, delegated to AssemblyScript's String after reading the view's range.

str.from("Hello, World").toUpperCase(); // "HELLO, WORLD"
str.toLowerCase("HeLLo"); // "hello"

toString

toString() materializes the view into a fresh owned string — the canonical "leave the view world" call.

str.slice("hello, world", 7).toString(); // "world"