Emulate ac-dwim behavior (of auto-complete.el) with company.el.

Comparisons with company-tng:

• company-preview-* frontends are integrated to company-dwim-frontend

• company-selection-default is not disabled, so that

  • RET can also perform completion
  • first tooltip item looks like selected by default
  • completion is automatically finished when pressing TAB with sole candidate

• company-abort (C-g) does not undo completion (use the basic undo command to undo)

When you press TAB once, company-dwim completes the common part like company-complete-common.

When you press TAB again, company-dwim selects and completes the first candidate.

When you press TAB again, company-dwim undoes the first candidate, then selects and completes the second candidate instead.

You may press TAB again and again to cycle through the candidates.

Unlike the built-in command company-complete-common-or-cycle, company-dwim selects and complets a candidate, where company-complete-common-or-cycle just selects. So that you do not need to press RET explicitly after selecting a candidate.

Note: This behavior is NOT enabled for flex matches

Load this package, bind TAB to company-dwim, and put company-dwim-frontend to company-frontends.

(require 'company-dwim)
(define-key company-active-map (kbd "TAB") 'company-dwim)
(setq company-frontends
      '(company-pseudo-tooltip-unless-just-one-frontend
        company-dwim-frontend
        company-echo-metadata-frontend))

When setting company-frontends, you also need to remove company-preview-*-frontends since they are integrated to company-dwim-frontend.