Method prefixToken

backend/plugin/parser/pg/completion.go:238–261

prefixToken returns the token immediately before (or containing) the cursor position when that token is an identifier-like token that the user is still typing. Returns false if no such token exists.

()

// position when that token is an identifier-like token that the user is still
// typing.  Returns false if no such token exists.
func (c *Completer) prefixToken() (pgparser.Token, bool) {
	// caretTokenIndex points to the first token at or past cursorByteOffset.
	// The partial-prefix token is the one just before it (when the cursor is
	// right after it) or the token itself (when the cursor is inside it).
	idx := c.caretTokenIndex

	// Check if the cursor is inside the token at caretTokenIndex.
	if idx < len(c.tokens) {
		tok := c.tokens[idx]
		if tok.Loc < c.cursorByteOffset && c.cursorByteOffset <= tok.End && isIdentLikeToken(tok.Type) {
			return tok, true
		}
	}

	// Check the token before caretTokenIndex (cursor is right after it).
	if idx > 0 {
		tok := c.tokens[idx-1]
		if tok.End == c.cursorByteOffset && isIdentLikeToken(tok.Type) {
			return tok, true
		}
	}

	return pgparser.Token{}, false
}

// isIdentLikeToken returns true for token types that represent identifiers or
// unreserved keywords that a user might be partially typing.