chore: vendor

vendor/github.com/rivo/uniseg/word.go

@@ -0,0 +1,89 @@
+package uniseg
+
+import "unicode/utf8"
+
+// FirstWord returns the first word found in the given byte slice according to
+// the rules of [Unicode Standard Annex #29, Word Boundaries]. This function can
+// be called continuously to extract all words from a byte slice, as illustrated
+// in the example below.
+//
+// If you don't know the current state, for example when calling the function
+// for the first time, you must pass -1. For consecutive calls, pass the state
+// and rest slice returned by the previous call.
+//
+// The "rest" slice is the sub-slice of the original byte slice "b" starting
+// after the last byte of the identified word. If the length of the "rest" slice
+// is 0, the entire byte slice "b" has been processed. The "word" byte slice is
+// the sub-slice of the input slice containing the identified word.
+//
+// Given an empty byte slice "b", the function returns nil values.
+//
+// [Unicode Standard Annex #29, Word Boundaries]: http://unicode.org/reports/tr29/#Word_Boundaries
+func FirstWord(b []byte, state int) (word, rest []byte, newState int) {
+	// An empty byte slice returns nothing.
+	if len(b) == 0 {
+		return
+	}
+
+	// Extract the first rune.
+	r, length := utf8.DecodeRune(b)
+	if len(b) <= length { // If we're already past the end, there is nothing else to parse.
+		return b, nil, wbAny
+	}
+
+	// If we don't know the state, determine it now.
+	if state < 0 {
+		state, _ = transitionWordBreakState(state, r, b[length:], "")
+	}
+
+	// Transition until we find a boundary.
+	var boundary bool
+	for {
+		r, l := utf8.DecodeRune(b[length:])
+		state, boundary = transitionWordBreakState(state, r, b[length+l:], "")
+
+		if boundary {
+			return b[:length], b[length:], state
+		}
+
+		length += l
+		if len(b) <= length {
+			return b, nil, wbAny
+		}
+	}
+}
+
+// FirstWordInString is like [FirstWord] but its input and outputs are strings.
+func FirstWordInString(str string, state int) (word, rest string, newState int) {
+	// An empty byte slice returns nothing.
+	if len(str) == 0 {
+		return
+	}
+
+	// Extract the first rune.
+	r, length := utf8.DecodeRuneInString(str)
+	if len(str) <= length { // If we're already past the end, there is nothing else to parse.
+		return str, "", wbAny
+	}
+
+	// If we don't know the state, determine it now.
+	if state < 0 {
+		state, _ = transitionWordBreakState(state, r, nil, str[length:])
+	}
+
+	// Transition until we find a boundary.
+	var boundary bool
+	for {
+		r, l := utf8.DecodeRuneInString(str[length:])
+		state, boundary = transitionWordBreakState(state, r, nil, str[length+l:])
+
+		if boundary {
+			return str[:length], str[length:], state
+		}
+
+		length += l
+		if len(str) <= length {
+			return str, "", wbAny
+		}
+	}
+}