Dictionary and Next-Word Completion for Vim using Google Ngrams English Corpus

Traditional dictionary based word completion is more or less useless since it prioritizes obsure words over frequently used words. A better approach is to use unigrams (list of most frequently used words in English corpus).

Data comes from ngrams sourced from Google Web Trillion Word Corpus. Unigrams file has 333,333 most frequently occuring words and bigrams file has 286,358 pairs of words. No additional download is necessary. Unigrams complete single words while bigrams suggest next word. Both uppercase and camelcase are respected. Bigram completion is turned off by default.

There is also an option to complete words within the comment section of source code.

This plugin is a helper for Vim completion plugin Vimcomplete.

Note: Unigram and bigram files cannot be sorted alphabetically. To make search efficient associative arrays (|Dictionaries|) are used. There is one-time upfront cost (~0.8 sec for unigrams and bigrams each) associated with creating data structures. There is no degradation in startup performance since processing is done asynchronously.

Requirements

• Vim >= 9.0
• Vimcomplete

Installation

Install this plugin after installing Vimcomplete.

Install using vim-plug.

vim9script
plug#begin()
Plug 'girishji/ngram-complete.vim'
plug#end()

For those who prefer legacy script.

call plug#begin()
Plug 'girishji/ngram-complete.vim'
call plug#end()

Or use Vim's builtin package manager.

Configuration

Default options are as follows.

vim9script
export var options: dict<any> = {
    enable: true,    # Enable this plugin
    priority: 10,    # Higher priority items are shown at the top
    maxCount: 5,     # Maximum number of items shown
    bigram: false,   # 'true' to enable next-word completion
    filetypes: ['text', 'markdown'], # Enable completion for these filetypes only ('*' for all)
    filetypesComments: [], # Enable completion only in comments
}

It is possible to complete words only in the comment section of source code files. filetypesComments should be set to a list of file types (ex. ['c', 'cpp', 'python']).

Options can be modified using g:VimCompleteOptionsSet(). It takes a dictionary argument. If you are using vim-plug, call this function through VimEnter autocommand event.

autocmd VimEnter * g:VimCompleteOptionsSet(options)