Skip to content

Instantly share code, notes, and snippets.

What would you like to do?
Simple Matlab utility to test and return the relative precedence of the given arguments. Inspired by Matt J's answer to the Matlab Answers question "How can I determine if one class is superior or inferior to another?" (
function [priority,classes] = argPrecedence(varargin)
% argPrecedence Return the relative class priority of the arguments
% Returns an array the same size as the argument list with each argument's
% relative priority level, with 1 as the highest.
% Optionally returns a second output of class names, with the unique classes
% of the argument list arranged in priority order.
% Note that the priority is dependent both on argument position and class.
priority = nan(size(varargin));
classes = cellfun(@class,varargin,'un',false);
args = varargin;
arg_idxs = 1:numel(args);
arg_classes = classes;
p = 1;
while ~isempty(args)
catch ME
C = textscan(ME.message,'%s','delimiter','''');
superior_class = C{1}{4}; % Dependent on locale, probably.
mask = strcmp(arg_classes,superior_class);
assert(any(mask),'The error message does not have a class of an argument')
priority(arg_idxs(mask)) = p;
p = p + 1;
args(mask) = [];
arg_idxs(mask) = [];
arg_classes(mask) = [];
error('function should always error')
assert(~any(isnan(priority)),'Some arguments were not assigned a priority.')
if nargout > 1
% Return class names in priority order
[~,idxs] = sort(priority);
classes = unique(classes(idxs),'stable');
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment