You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: uminus.m
    path of file: ./repos/chebfun/@chebop
    
    the code of the file until where you have to start completion: function A = uminus(A)
%-   CHEBOP unary minus.
%   -A negates the operator of the CHEBOP A. Boundary conditions are not
%   affected.
%
%   UMINUS(A) is called for the syntax '-A'.

% Copyright 2017 by The University of Oxford and The Chebfun Developers.
% See http://www.chebfun.org/ for Chebfun information.


    
function A = uminus(A)
%-   CHEBOP unary minus.
%   -A negates the operator of the CHEBOP A. Boundary conditions are not
%   affected.
%
%   UMINUS(A) is called for the syntax '-A'.

% Copyright 2017 by The University of Oxford and The Chebfun Developers.
% See http://www.chebfun.org/ for Chebfun information.

if ( isempty(A.op ) )
    return
else
    
    % Make the pretty string:
    funArgs = getFunArgs(A);
    argStr = ['@(',funArgs,')'];
    if ( ~isempty(A.opShow) )
        op = A.opShow;
    else
        op = func2str(A.op);
    end