(defcstruct pango-log-attr
  (is-line-break :uint)
  (is-mandatory-break :uint)
  (is-char-break :uint)
  (is-white :uint)
  (is-cursor-position :uint)
  (is-word-start :uint)
  (is-word-end :uint)
  (is-sentence-boundary :uint)
  (is-sentence-start :uint)
  (is-sentence-end :uint)
  (backspcaces-deletes-character :uint)
  (is-expandable-space :uint)
  (is-word-boundary :uint))  

is-line-break

If set, can break line in front of character.

is-mandatory-break

If set, must break line in front of character.

is-char-break

If set, can break here when doing character wrapping.

is-white

Is whitespace character.

is-cursor-position

If set, cursor can appear in front of character. I.e. this is a grapheme boundary, or the first character in the text. This flag implements Unicode's Grapheme Cluster Boundaries semantics.

is-word-start

Is first character in a word.

is-word-end

Is first non-word char after a word. Note that in degenerate cases, you could have both is-word-start and is-word-end set for some character.

is-sentence-boundary

Is a sentence boundary. There are two ways to divide sentences. The first assigns all inter-sentence whitespace/control/format chars to some sentence, so all chars are in some sentence; is-sentence-boundary denotes the boundaries there. The second way does not assign between-sentence spaces, etc. to any sentence, so is-sentence_start/is-sentence-end mark the boundaries of those sentences.

is-sentence-start

Is first character in a sentence.

is-sentence-end

Is first char after a sentence. Note that in degenerate cases, you could have both is-sentence-start and is-sentence-end set for some character, e.g. no space after a period, so the next sentence starts right away.

backspace-deletes-character

If set, backspace deletes one character rather than the entire grapheme cluster. This field is only meaningful on grapheme boundaries, where is-cursor-position is set. In some languages, the full grapheme, e.g. letter + diacritics, is considered a unit, while in others, each decomposed character in the grapheme is a unit. In the default implementation of pango-break, this bit is set on all grapheme boundaries except those following Latin, Cyrillic or Greek base characters.

is-expandable-space

Is a whitespace character that can possibly be expanded for justification purposes.

is-word-boundary

Is a word boundary. More specifically, means that this is not a position in the middle of a word. For example, both sides of a punctuation mark are considered word boundaries. This flag is particularly useful when selecting text word-by-word. This flag implements Unicode's Word Boundaries semantics.