How to find required inputs from Input Parser object?

Hi Community,

I am have implemented 'InputParser' for my MATLAB function. Here's the code snippet-

function fitElliOntoDatam_10_edit(filen,NrPlanes,makePlots)

defaultMakePlot = false;

%%%%%%% INPUT PARSER %%%%%%%%
p = inputParser;
p.FunctionName = 'fitElliOntoDatam_10_edit';
validNum = @(x) isnumeric(x) && (x > 0);

addRequired(p,'filen',@isstring);
addRequired(p,'NrPlanes',validNum);
addOptional(p,'makePlots',defaultMakePlot,@islogical);

parse(p,filen,NrPlanes,makePlots);

disp(p);
.....
......

So, when I print the inputParser object, I get the following detail -

>> fitElliOntoDatam_10_edit("export.txt",20,false)
  inputParser with properties:

       FunctionName: 'fitElliOntoDatam_10_edit'
      CaseSensitive: 0
      KeepUnmatched: 0
    PartialMatching: 1
       StructExpand: 1
         Parameters: {'filen'  'makePlots'  'NrPlanes'}
            Results: [1×1 struct]
          Unmatched: [1×1 struct]
      UsingDefaults: {1×0 cell}

How can I display which of these 3 parameters are 'required' or 'optional'? Where is that information stored inside inputParser object?

Also can I display the data type of these parameters from the inputParser object? Where do the validation functions get stored ?

[Steven Lord]

I'm not sure that information is available from the inputParser object. Can you share more information about how you're hoping to use that information, what you would do with it if it was available? There may be alternate ways to accomplish your goal using different functions.

[Atin]

Thank you for asking Steven!

The idea is to extract information from every MATLAB Function file (that I use) about -

1. name of the function
2. its parameters and their name, type, default value, required/optional status, positional or not

And after extracting the data convert it into an XML like -

<?xml version='1.0' encoding='UTF-8'?>
<program name="fitElliOntoDatam_10_edit" description="Simple program....">
  <param type="string" name="filen" positional="true" required="true" description="name of the file" />
  <param type="double" name="NrPlanes" positional="true" required="true" description="no. of planes" />
  <param type="logical/boolean" name="makePlots" positional="true" required="false" default=false description="Flag for..." />
</program>

I assumed inputParser would serve the purpose and started with it.

[Steven Lord]

How do you intend or hope to use that XML file?

We have the capability to obtain class metadata but I don't believe there's an equivalent for functions.

If you had written or can write a functionSignatures.json file to customize suggestions and completions for your functions, parsing that JSON file might be an easier approach for gathering some of the data you're looking for.

[Atin]

The intention is to have an XML representation of 'help' option for MATLAB functions, similar to what is being done by xmlhelpy (for Python).

I will look into class metadata and customize code suggestions and completions.

I came across 'mlint' while searching google. Is that something which could be useful?

[Atin]

I tried writing 'functionSignatures.json'. Is there any way to validate the inputs that I manually write in 'functionSignatures.json' ? Even when I write only one input, it gets validated by validateFunctionSignaturesJSON.

{
  "_schemaVersion": "1.0.0",
  "fitElliOntoDatam_10_edit":
  {
     "inputs":
     [
        {"name":"in1", "kind":"required", "type":["file"], "purpose":"Name of file with data"},
        {"name":"in2", "kind":"required", "type":["numeric"], "purpose":"Number of point in z-direction"},
        {"name":"in3", "kind":"ordered", "type":["logical"], "purpose":"Boolean flag for creating or not creating plots"}
     ]
  }
}

On the other hand, 'mlint' provides a list of all variables in the m-file and 'mtree' provides a M parse tree. Is there a way to exploit these libraries to get 'type' and 'kind' of the variables @Steven Lord?

>> mlint('fitElliOntoDatam_10_edit','-edit')
  0               <VOID>  -1 E 
  1 fitElliOntoDatam_10_edit   0 F  1/10
  2                filen   1 V 
  3             NrPlanes   1 V 
  4            makePlots   1 V 
  5      defaultMakePlot   1 V 
  6                false   1 F  Amb
  7                    p   1 V 
  8          inputParser   1 F  Amb
  9             validNum   1 V 
 10            isnumeric   1 F  Amb
 11          addRequired   1 F  Amb
 ..         ............   . .  ....

mtree

 1=== * FUNCTION: 1/01 
 2=== * ETC: 1/10 
 3=== * ETC: 1/34 
 4=== * ID: 1/10 (fitElliOntoDatam_10_edit)
 5=== * ID: 1/35 (filen)
 6=== > ID: 1/41 (NrPlanes)
 7=== > ID: 1/50 (makePlots)
 8=== * EXPR: 17/17 
 9=== * EQUALS: 17/17 
 10=== * ID: 17/01 (defaultMakePlot)
 11=== * CALL: 17/19 
 12=== * ID: 17/19 (false)
 13=== > EXPR: 20/03 
 14=== * EQUALS: 20/03 
 15=== * ID: 20/01 (p)
 16=== * CALL: 20/05 
 17=== * ID: 20/05 (inputParser)
 18=== > EXPR: 21/16 
 19=== * EQUALS: 21/16 
 20=== * DOT: 21/02 
 21=== * ID: 21/01 (p)
 22=== * FIELD: 21/03 (FunctionName)
 23=== * CHARVECTOR: 21/18 ('fitElliOntoDatam_10_edit')
 24=== > EXPR: 22/10 
 25=== * EQUALS: 22/10 
 26=== * ID: 22/01 (validNum)
 27=== * ANON: 22/12 
 28=== * ANONID: 22/14 (x)
 29=== * ANDAND: 22/30 
 30=== * CALL: 22/26 
 31=== * ID: 22/17 (isnumeric)
 32=== * ANONID: 22/27 (x)
 33=== * PARENS: 22/33 
 34=== * GT: 22/36 
 35=== * ANONID: 22/34 (x)
 36=== * INT: 22/38 (0)
 37=== > EXPR: 24/12 
 38=== * CALL: 24/12 
 39=== * ID: 24/01 (addRequired)
 40=== * ID: 24/13 (p)
 41=== > CHARVECTOR: 24/15 ('filen')
 42=== > AT: 24/23 
 43=== * ID: 24/24 (isstring)
 44=== > EXPR: 25/12 
 45=== * CALL: 25/12 
 46=== * ID: 25/01 (addRequired)
 47=== * ID: 25/13 (p)
 48=== > CHARVECTOR: 25/15 ('NrPlanes')
 49=== > ID: 25/26 (validNum)
 50=== > EXPR: 26/12 
 51=== * CALL: 26/12 
 52=== * ID: 26/01 (addOptional)
 53=== * ID: 26/13 (p)
 54=== > CHARVECTOR: 26/15 ('makePlots')
 55=== > ID: 26/27 (defaultMakePlot)
 56=== > AT: 26/43 
 57=== * ID: 26/44 (islogical)
 58=== > EXPR: 28/06 
 59=== * CALL: 28/06 
 60=== * ID: 28/01 (parse)
 61=== * ID: 28/07 (p)
 62=== > ID: 28/09 (filen)
 63=== > ID: 28/15 (NrPlanes)
 64=== > ID: 28/24 (makePlots)