Version of inputname to call outside of a function?

Essentially, I'm looking for a way to get the names of inputs to a function. I know you can get the number with nargin...

I'm writing a testing framework, so i want to be able to provide the name of the function to the framework and have it prompt the user for test values.

[Guillaume]

It's not clear what you're asking. Why do you care about the names that the function uses for its inputs. That doesn't affect in any way the calling code.

[Lena]

I want to be able to prompt the user, i.e.

1) I call testfunc.m('function_to_test')

2) it finds function_to_test.m in the directory

3) i get the names of arguments to function_to_test

4) val = input('user please input %s, 'string_from_step_3')

5) run function_to_test(val)

[Stephen23]

The names that are used for input/output arguments when a function is called are totally unrelated to the names that are used in the function's internal workspace, and it would be a pointlessly slow process to try and find them out. Such introspective programming is not efficient.

Answer 1

[TADA]

If this is a method in a class you can use metaclass.

If it's a function I don't think there's a builtin way to inspect it like that, however for anonymous functions you can parse the function using func2str and with .m files you can parse the file itself

function [args, status] = inspectArgs(foo)
% This function takes in a function handle and finds its decleration
% with .m file functions and scoped functions, the declaration is found
% within the .m file
% with anonymous functions, the decleration is found using func2str
  status = 'ok';

    % Get function content for anonymous functions and function name for
    % .m file functions
    fullFuncName = func2str(foo);

    match = regexp(fullFuncName, '^@\((?<args>[^\)]*\).*', 'names');
    if ~isempty(match)
        % anonymous functions
        args = regexp(match.args, '\s*,\s*', 'split');
        return;
    end

    path = which(fullFuncName);
    declerationPostfix = '';
    if exist(fullFuncName, 'builtin')
        % builtin functions
        tok = regexp(path, '\((?<fname>.*)\)','names');
        path = tok.fname;
        if length(path) < 3 || ~endsWith(path, '.m', 'IgnoreCase', true)
            path = [path '.m'];
        end

        % Builtin functions .m files may have a function declerations
        % without the function keyword
        declerationPostfix = '?';
    elseif isempty(path)
        % Scoped functions
        info = functions(foo);
        if ~isempty(info.file)
            path = info.file;
        else
            status = 'file not found';
            args = {};
            return;
        end
    end

    % truncate namespaces
    dotIndex = find(fullFuncName == '.', 1, 'last');
    if isempty(dotIndex)
        funcName = fullFuncName;
    else
        funcName = fullFuncName(dotIndex+1:end);
    end

    % Read .m file
    fid = fopen(path, 'r');
    text = fread(fid, '*char')';
    fclose(fid);

    % find function decleration
    match = regexpi(text, ['(function\s*(\[?[\w\,\s]*\]?\s*=)?\s*)' declerationPostfix funcName '\([^\)]*\)'], 'match', 'once');
    if isempty(match)
        args = {};
        status = 'parse error';
    else
        % Find foo(args)
        match2 = regexpi(match, [funcName '\([^\)]*\)'], 'match', 'once');

        % crop only the args part
        argString = strtrim(match2(length(funcName)+2:end-1));
        if isempty(argString)
            args = {};
        else

            args = regexp(argString, '\s*,\s*', 'split');
        end
    end
end

You should check out Matlabs testing framework for automated unit tests

Answer 2

[Walter Roberson]

Take advantage of the function signatures that MATLAB itself uses.

https://www.mathworks.com/help/matlab/release-notes.html?rntext=completion&startrelease=R2018a&endrelease=R2018b&groupby=release&sortby=descending&searchHighlight=completion