invlist_and -- invreted index toy program by Yoshihiko Suhara (sleepy_yoshi)

• About This program is a toy program, which aims to help to someone who studies about search engines, especially AND retrieval with inverted indexes.

• How to use? You must change the current directory to the directory that has index files.

=== % cd index % ls foo fuga hoge piyo % ../invlist_and foo fuga hoge piyo inverted lists for input query === foo -> 7: 1 5 6 7 8 9 10 fuga -> 3: 1 4 5 hoge -> 5: 1 2 3 4 5 piyo -> 2: 4 5

ordered list=== piyo -> 2: 4 5 fuga -> 3: 1 4 5 hoge -> 5: 1 2 3 4 5 foo -> 7: 1 5 6 7 8 9 10

Intersection of piyo and fuga: 4 5 Intersection of last result and hoge: 4 5 Intersection of last result and foo: 5

search result === result num: 1 5

• Index format

  % cat hoge 5 1 2 3 4 5

  First number '5' means document frequency (DF) of this inverted list. Following numbers indicate document IDs that contain the word 'hoge'.

• See also There's more details about this program in a blog article below. (in Japanese) http://d.hatena.ne.jp/sleepy_yoshi/20091009/p1