ScalarIterator

Module std.iteration

import std.iteration;

Public declaration contracts and authored examples. A page can document several related symbols. Implementation bodies are excluded.

ScalarIterator

pub final class ScalarIterator

Traverses one valid UTF-8 view as Unicode scalar values.

The cursor borrows the original byte storage through a shrinking str view, allocates nothing, and performs one bounded UTF-8 decode per item. Its constructor/factory/step also support required constant evaluation when the borrowed input is evaluator-owned immutable UTF-8 storage.

Example

module example.scalar_iterator;
fn Main() -> i32 {
    var Cursor = "Aλ".CreateIterator();
    var Count = 0;
    while Cursor.Next() is .Some { Value = _ } {
        Count += 1;
    }
    // Direct range syntax uses the same authenticated scalar-cursor protocol.
    var DirectCount = 0;
    for Scalar in "Aλ" { DirectCount += 1; }
    for Scalar in "" { return 1; }
    if DirectCount != Count { return 2; }
    return Count - 2;
}

ScalarIterator.fn

pub const fn Next() -> char?

Decodes and consumes the next Unicode scalar. Return: The next scalar by value, or none when no bytes remain. Warning: The cursor remains valid only while the original backing storage remains live and unmoved.