}
}
}
private _primary(): ContextKeyExpression | undefined {
const peek = this._peek();
switch (peek.type) {
case TokenType.True:
this._advance();
return ContextKeyExpr.true();
case TokenType.False:
this._advance();
return ContextKeyExpr.false();
case TokenType.LParen: {
this._advance();
const expr = this._expr();