Documentation
¶
Index ¶
- Variables
- func Repeat(c rune, n int) string
- func Reverse(s string) string
- func ToggleRuneCase(r rune) rune
- type LineMatch
- type Reader
- type ReverseReader
- type RuneStack
- type Searcher
- type Tree
- func (t *Tree) DeleteAtPosition(charPos uint64) (bool, rune)
- func (t *Tree) InsertAtPosition(charPos uint64, c rune) error
- func (t *Tree) LineNumForPosition(charPos uint64) uint64
- func (t *Tree) LineStartPosition(lineNum uint64) uint64
- func (t *Tree) NumChars() uint64
- func (t *Tree) NumLines() uint64
- func (t *Tree) ReaderAtPosition(charPos uint64) Reader
- func (t *Tree) ReverseReaderAtPosition(charPos uint64) ReverseReader
- func (t *Tree) String() string
Constants ¶
This section is empty.
Variables ¶
var (
ErrInvalidUtf8 = fmt.Errorf("invalid UTF-8")
)
Functions ¶
func ToggleRuneCase ¶
ToggleRuneCase changes the case of the rune from lower-to-upper or vice-versa.
Types ¶
type Reader ¶ added in v0.3.0
type Reader struct {
// contains filtered or unexported fields
}
Reader reads UTF-8 bytes from a text.Tree. It implements io.Reader. Copying the struct produces a new, independent reader. text.Tree is NOT thread-safe, so reading from a tree while modifying it is undefined behavior!
type ReverseReader ¶ added in v0.3.0
type ReverseReader struct {
Reader
}
ReverseReader reads bytes in reverse order.
type RuneStack ¶ added in v1.3.0
type RuneStack struct {
// contains filtered or unexported fields
}
RuneStack represents a string with efficient operations to push/pop runes. The zero value is equivalent to an empty string.
type Searcher ¶
type Searcher struct {
// contains filtered or unexported fields
}
Searcher searches for an exact match of a query. It uses the Knuth-Morris-Pratt algorithm, which runs in O(n+m) time, where n is the length of the text and m is the length of the query.
func NewSearcher ¶
func (*Searcher) LastInReader ¶ added in v0.5.0
LastInReader finds the last occurrence of a query in the text produced by an io.Reader. If it finds a match, it returns the offset (in rune positions) from the start of the reader.
func (*Searcher) Limit ¶ added in v0.2.0
Limit sets the maximum offset (in rune positions) for the end of a match. For example, a limit of 3 would allow matches that end on the second rune from the reader, but not on the following runes.
func (*Searcher) NextInReader ¶
NextInReader finds the next occurrence of a query in the text produced by an io.Reader. If it finds a match, it returns the offset (in rune positions) from the start of the reader.
type Tree ¶
type Tree struct {
// contains filtered or unexported fields
}
text.Tree is a data structure for representing UTF-8 text. It supports efficient insertions, deletions, and lookup by character offset and line number. It is inspired by two papers: Boehm, H. J., Atkinson, R., & Plass, M. (1995). Ropes: an alternative to strings. Software: Practice and Experience, 25(12), 1315-1330. Rao, J., & Ross, K. A. (2000, May). Making B+-trees cache conscious in main memory. In Proceedings of the 2000 ACM SIGMOD international conference on Management of data (pp. 475-486). Like a rope, the tree maintains character counts at each level to efficiently locate a character at a given offset. To use the CPU cache efficiently, all children of a node are pre-allocated in a group (what the Rao & Ross paper calls a "full" cache-sensitive B+ tree), and the parent uses offsets within the node group to identify child nodes. All nodes are carefully designed to fit as much data as possible within a 64-byte cache line.
func NewTreeFromReader ¶
NewTreeFromReader creates a new Tree from a reader that produces UTF-8 text. This is more efficient than inserting the bytes into an empty tree. Returns an error if the bytes are invalid UTF-8.
func NewTreeFromString ¶
NewTreeFromString creates a new Tree from a UTF-8 string.
func (*Tree) DeleteAtPosition ¶
DeleteAtPosition removes the UTF-8 character at the specified position (0-indexed). If charPos is past the end of the text, this has no effect.
func (*Tree) InsertAtPosition ¶
InsertAtPosition inserts a UTF-8 character at the specified position (0-indexed). If charPos is past the end of the text, it will be appended at the end. Returns an error if c is not a valid UTF-8 character.
func (*Tree) LineNumForPosition ¶
LineNumForPosition returns the line number (0-indexed) for the line containing the specified position.
func (*Tree) LineStartPosition ¶
LineStartPosition returns the position of the first character at the specified line (0-indexed). If the line number is greater than the maximum line number, returns one past the position of the last character.
func (*Tree) ReaderAtPosition ¶
ReaderAtPosition returns a reader starting at the UTF-8 character at the specified position (0-indexed). If the position is past the end of the text, the returned reader will read zero bytes.
func (*Tree) ReverseReaderAtPosition ¶ added in v0.3.0
func (t *Tree) ReverseReaderAtPosition(charPos uint64) ReverseReader
ReverseReaderAtPosition returns a reverse reader starting at the specified position.
Source Files
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