chore: go mod tidy / vendor / make deps

vendor/github.com/clipperhouse/uax29/v2/internal/iterators/iterator.go

@@ -0,0 +1,85 @@
+package iterators
+
+type Stringish interface {
+	[]byte | string
+}
+
+type SplitFunc[T Stringish] func(T, bool) (int, T, error)
+
+// Iterator is a generic iterator for words that are either []byte or string.
+// Iterate while Next() is true, and access the word via Value().
+type Iterator[T Stringish] struct {
+	split SplitFunc[T]
+	data  T
+	start int
+	pos   int
+}
+
+// New creates a new Iterator for the given data and SplitFunc.
+func New[T Stringish](split SplitFunc[T], data T) *Iterator[T] {
+	return &Iterator[T]{
+		split: split,
+		data:  data,
+	}
+}
+
+// SetText sets the text for the iterator to operate on, and resets all state.
+func (iter *Iterator[T]) SetText(data T) {
+	iter.data = data
+	iter.start = 0
+	iter.pos = 0
+}
+
+// Split sets the SplitFunc for the Iterator.
+func (iter *Iterator[T]) Split(split SplitFunc[T]) {
+	iter.split = split
+}
+
+// Next advances the iterator to the next token. It returns false when there
+// are no remaining tokens or an error occurred.
+func (iter *Iterator[T]) Next() bool {
+	if iter.pos == len(iter.data) {
+		return false
+	}
+	if iter.pos > len(iter.data) {
+		panic("SplitFunc advanced beyond the end of the data")
+	}
+
+	iter.start = iter.pos
+
+	advance, _, err := iter.split(iter.data[iter.pos:], true)
+	if err != nil {
+		panic(err)
+	}
+	if advance <= 0 {
+		panic("SplitFunc returned a zero or negative advance")
+	}
+
+	iter.pos += advance
+	if iter.pos > len(iter.data) {
+		panic("SplitFunc advanced beyond the end of the data")
+	}
+
+	return true
+}
+
+// Value returns the current token.
+func (iter *Iterator[T]) Value() T {
+	return iter.data[iter.start:iter.pos]
+}
+
+// Start returns the byte position of the current token in the original data.
+func (iter *Iterator[T]) Start() int {
+	return iter.start
+}
+
+// End returns the byte position after the current token in the original data.
+func (iter *Iterator[T]) End() int {
+	return iter.pos
+}
+
+// Reset resets the iterator to the beginning of the data.
+func (iter *Iterator[T]) Reset() {
+	iter.start = 0
+	iter.pos = 0
+}