Code completion has become a common practice for programmers during their daily programming activities. It automatically predicts the next tokens or statements that the programmers may use. Code completion aims to substantially save keystrokes and improve the programming efficiency for programmers. Although there exists substantial research on code completion, it is still unclear what practitioner expectations are on code completion and whether these expectations are met by the existing research. To address these questions, we perform a study by first interviewing 15 professionals and then surveying 599 practitioners from 18 IT companies about their expectations on code completion. We then compare the practitioner expectations with the existing research by conducting a literature review of papers on code completion published in major publication venues from 2012 to 2022. Based on the comparison, we highlight the directions desirable for researchers to invest efforts toward developing code completion techniques for meeting practitioner expectations.