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Diffstat (limited to 'vendor/github.com/rivo/uniseg/line.go')
| -rw-r--r-- | vendor/github.com/rivo/uniseg/line.go | 134 |
1 files changed, 0 insertions, 134 deletions
diff --git a/vendor/github.com/rivo/uniseg/line.go b/vendor/github.com/rivo/uniseg/line.go deleted file mode 100644 index 7a46318d9..000000000 --- a/vendor/github.com/rivo/uniseg/line.go +++ /dev/null @@ -1,134 +0,0 @@ -package uniseg - -import "unicode/utf8" - -// FirstLineSegment returns the prefix of the given byte slice after which a -// decision to break the string over to the next line can or must be made, -// according to the rules of [Unicode Standard Annex #14]. This is used to -// implement line breaking. -// -// Line breaking, also known as word wrapping, is the process of breaking a -// section of text into lines such that it will fit in the available width of a -// page, window or other display area. -// -// The returned "segment" may not be broken into smaller parts, unless no other -// breaking opportunities present themselves, in which case you may break by -// grapheme clusters (using the [FirstGraphemeCluster] function to determine the -// grapheme clusters). -// -// The "mustBreak" flag indicates whether you MUST break the line after the -// given segment (true), for example after newline characters, or you MAY break -// the line after the given segment (false). -// -// This function can be called continuously to extract all non-breaking sub-sets -// 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 line segment. If the length of the -// "rest" slice is 0, the entire byte slice "b" has been processed. The -// "segment" byte slice is the sub-slice of the input slice containing the -// identified line segment. -// -// Given an empty byte slice "b", the function returns nil values. -// -// Note that in accordance with [UAX #14 LB3], the final segment will end with -// "mustBreak" set to true. You can choose to ignore this by checking if the -// length of the "rest" slice is 0 and calling [HasTrailingLineBreak] or -// [HasTrailingLineBreakInString] on the last rune. -// -// Note also that this algorithm may break within grapheme clusters. This is -// addressed in Section 8.2 Example 6 of UAX #14. To avoid this, you can use -// the [Step] function instead. -// -// [Unicode Standard Annex #14]: https://www.unicode.org/reports/tr14/ -// [UAX #14 LB3]: https://www.unicode.org/reports/tr14/#Algorithm -func FirstLineSegment(b []byte, state int) (segment, rest []byte, mustBreak bool, 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, true, lbAny // LB3. - } - - // If we don't know the state, determine it now. - if state < 0 { - state, _ = transitionLineBreakState(state, r, b[length:], "") - } - - // Transition until we find a boundary. - var boundary int - for { - r, l := utf8.DecodeRune(b[length:]) - state, boundary = transitionLineBreakState(state, r, b[length+l:], "") - - if boundary != LineDontBreak { - return b[:length], b[length:], boundary == LineMustBreak, state - } - - length += l - if len(b) <= length { - return b, nil, true, lbAny // LB3 - } - } -} - -// FirstLineSegmentInString is like [FirstLineSegment] but its input and outputs -// are strings. -func FirstLineSegmentInString(str string, state int) (segment, rest string, mustBreak bool, 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, "", true, lbAny // LB3. - } - - // If we don't know the state, determine it now. - if state < 0 { - state, _ = transitionLineBreakState(state, r, nil, str[length:]) - } - - // Transition until we find a boundary. - var boundary int - for { - r, l := utf8.DecodeRuneInString(str[length:]) - state, boundary = transitionLineBreakState(state, r, nil, str[length+l:]) - - if boundary != LineDontBreak { - return str[:length], str[length:], boundary == LineMustBreak, state - } - - length += l - if len(str) <= length { - return str, "", true, lbAny // LB3. - } - } -} - -// HasTrailingLineBreak returns true if the last rune in the given byte slice is -// one of the hard line break code points defined in LB4 and LB5 of [UAX #14]. -// -// [UAX #14]: https://www.unicode.org/reports/tr14/#Algorithm -func HasTrailingLineBreak(b []byte) bool { - r, _ := utf8.DecodeLastRune(b) - property, _ := propertyLineBreak(r) - return property == prBK || property == prCR || property == prLF || property == prNL -} - -// HasTrailingLineBreakInString is like [HasTrailingLineBreak] but for a string. -func HasTrailingLineBreakInString(str string) bool { - r, _ := utf8.DecodeLastRuneInString(str) - property, _ := propertyLineBreak(r) - return property == prBK || property == prCR || property == prLF || property == prNL -} |