Documentation
¶
Overview ¶
Package idx implements reading .idx files.
The .idx file contains a list of dictionary entry titles and the associated offset and size of the main article content in the .dict file.
Each .idx file entry (word) comes in three parts:
- The title: a utf-8 string terminated by a null terminator ('\0').
- The offset: a 32 or 64 bit integer offset of the word in the .dict file in network byte order.
- The size: a 32 bit integer size of the word in the .dict file in network byte order.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( // ErrPrefix indicates that the query must not start with a glob wildcard. ErrPrefix = errors.New("search query must not start with wildcard") // ErrGlob indicates an error with a glob search query. ErrGlob = errors.New("invalid glob query") )
var DefaultOptions = &Options{ Folder: func() transform.Transformer { return transform.Nop }, ScannerOptions: &ScannerOptions{ OffsetBits: 32, }, }
DefaultOptions is the default options for an Idx.
var DefaultScannerOptions = &ScannerOptions{
OffsetBits: 32,
}
DefaultScannerOptions is the default options for a Scanner.
var ErrInvalidIdxOffset = errors.New("invalid idxoffsetbits")
ErrInvalidIdxOffset indicates that the OffsetBits is an invalid value.
Functions ¶
Types ¶
type Idx ¶
type Idx struct {
// contains filtered or unexported fields
}
Idx is a very basic implementation of an in memory search index. Implementers of dictionaries apps or tools may wish to consider using Scanner to read the .idx file and generate their own more robust search index.
func New ¶
func New(r io.ReadCloser, options *Options) (*Idx, error)
New returns a new in-memory index.
func NewFromIfoPath ¶
NewFromIfoPath returns a new in-memory index.
func NewWithSyn ¶
func NewWithSyn(idxReader, synReader io.ReadCloser, options *Options) (*Idx, error)
New returns a new in-memory index with synonyms merged in.
func (*Idx) Search ¶
Search performs a query of the index and returns matching words. The query supports glob patterns whose pattern syntax is:
pattern:
{ term }
term:
`*` matches any sequence of non-separator characters
`**` matches any sequence of characters
`?` matches any single non-separator character
`[` [ `!` ] { character-range } `]`
character class (must be non-empty)
`{` pattern-list `}`
pattern alternatives
c matches character c (c != `*`, `**`, `?`, `\`, `[`, `{`, `}`)
`\` c matches character c
character-range:
c matches character c (c != `\\`, `-`, `]`)
`\` c matches character c
lo `-` hi matches character c for lo <= c <= hi
pattern-list:
pattern { `,` pattern }
comma-separated (without spaces) patterns
The pattern is folded using the given folding transformer and matches the folded word in the index.
type Options ¶
type Options struct {
// Folder returns a [transform.Transformer] that performs folding (e.g.
// case folding, whitespace folding, etc.) on index entries.
Folder func() transform.Transformer
// ScannerOptions are the options to use when reading the .idx file.
ScannerOptions *ScannerOptions
}
Options are options for the idx data.
type Scanner ¶
type Scanner struct {
// contains filtered or unexported fields
}
Scanner scans an index from start to end.
func NewScanner ¶
func NewScanner(r io.ReadCloser, options *ScannerOptions) (*Scanner, error)
NewScanner return a new index scanner that scans the index from start to end. The Scanner assumes ownership of the reader and should be closed with the Close method.
func NewScannerFromIfoPath ¶
func NewScannerFromIfoPath(ifoPath string, options *ScannerOptions) (*Scanner, error)
NewScannerFromIfoPath returns a new in-memory index.
type ScannerOptions ¶
type ScannerOptions struct {
// OffsetBits are the number of bits in the offset fields. Valid values for
// OffsetBits are either 32 or 64.
OffsetBits int
}
ScannerOptions are options for scanning an .idx file.
Source Files