Class Tx::Index
In: tx.rb
Parent: Object

A class to access an index.

Methods

common_prefix_search   each   error_log   gsub   include   include?   longest_prefix   new   num_keys   open   predictive_search   result_log   scan   search_expansions   search_prefixes   to_a  

Included Modules

Enumerable

External Aliases

num_keys -> size

Attributes

encoding  [R]  Encoding object specified in new. nil in Ruby 1.8.

Public Class methods

new(file_name, encoding = nil)

Loads an index from a file named file_name. The index file can be generated with Tx::Builder.

e.g. index = Tx::Index.new("test.index")

Ruby 1.9 only: You can specify Encoding object as second parameter. It is used as encoding of result of search_prefixes, etc. Default is Encoding.default_internal (if it‘s nil, Encoding::UTF_8). Note that offsets (pos, len) returned by and given to Tx::Index is in byte unit, not character unit, even if encoding is specified.

Public Instance methods

common_prefix_search(str, pos= 0, len= -1)

Alias for search_prefixes

each(&block)

Iterates over all words in the index.

error_log()

Returns error log of index loading.

gsub(str) {|match, pos| ...}

Replaces all occurences of strings in the index in str using return value of the given block. Block is called with the string found and its position.

e.g. 

  index.gsub("hogefugabar"){ |s, i| s.upcase }
  #=> "HOGEfugaBAR"
include(str, pos= 0, len= -1)

Returns true if str is in the index.

e.g. index.include("hoge") #=> true if "hoge" is in the index

If pos and len are specified, searches str[pos, len] instead of whole str. (Negative pos is not supported.)

include?(str, pos= 0, len= -1)

Alias for include

longest_prefix(str, pos= 0, len= -1, match_prefix= false)

Searches the longest word in the index which is a prefix of str and returns the length of the word. If str itself is in the index, returns str.length. If no such word is found, returns -1.

e.g. index.longest_prefix("hoge") #=> 2 if "ho" is in the index

If pos and len are specified, searches str[pos, len] instead of whole str. (Negative pos is not supported.)

If match_prefix is true, searches a word which has the longest prefix in common with str and returns the length of the common prefix.

e.g. index.longest_prefix("hoge", 0, -1, true) #=> 3 if "hoga" is in the index

num_keys()

Returns the number of words in the index.

predictive_search(str, pos= 0, len= -1, limit= 0)

Alias for search_expansions

result_log()

Returns operation log of index loading.

scan(str) {|match, pos| ...}

Finds all occurences of strings in the index from str, and returns Array of pair of the string and its position.

e.g. index.scan("hogefugabar") #=> [["hoge", 0], ["bar", 8]]

If block is given, call it for each string and its position.

e.g. 

  index.scan("hogefugabar"){ |s, i| p [s, i] }
  #=> ["hoge", 0]
      ["bar", 8]
search_expansions(str, pos= 0, len= -1, limit= 0)

Enumerates all words in the index which begin with str. str is also returned if str itself is in the index.

e.g. index.search_expansions("hoge") #=> ["hoge", "hogeee", "hogeshi"]

If pos and len are specified, searches str[pos, len] instead of whole str. (Negative pos is not supported.)

If limit is non-zero, returns at most limit words.

search_prefixes(str, pos= 0, len= -1)

Enumerates all words in the index which are prefixes of str. str is also returned if str itself is in the index.

e.g. index.search_prefixes("hoge") #=> ["ho", "hoge"]

If pos and len are specified, searches str[pos, len] instead of whole str. (Negative pos is not supported.)

to_a()

Returns all words in the index as an Array.

[Validate]