[Octave-bug-tracker] [bug #60860] Implementation of memoize

[Guillaume]

URL:
  <https://savannah.gnu.org/bugs/?60860>

                 Summary: Implementation of memoize
                 Project: GNU Octave
            Submitted by: gyom
            Submitted on: Wed 30 Jun 2021 02:48:42 PM UTC
                Category: Octave Function
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Feature Request
                  Status: None
             Assigned to: None
         Originator Name: Guillaume
        Originator Email: 
             Open/Closed: Open
                 Release: dev
         Discussion Lock: Any
        Operating System: Any

    _______________________________________________________

Details:

There is a memoize functionality in Matlab wince R2017a:
https://www.mathworks.com/help/matlab/ref/memoize.html

I attach an early attempt to implement it and would welcome feedback.

Running the following in Matlab indicates that a handle class
matlab.lang.MemoizedFunction has to be defined. To implement the fact that the
memoizing the same function handle returns the same object, I store all of
them in a persistent variable in the memoize function. That said, the
clearAllMemoizedCaches function would require access to that variable too so
there could be an undocumented syntax in memoize that could be called from
clearAllMemoizedCaches or there need to be a separate function to take on the
role of keeping track of all memoized function handles.


>> a = memoize(@sin);
>> whos a
  Name    Size    Bytes    Class
  a       1x1         8    matlab.lang.MemoizedFunction
>> a
a = 
  MemoizedFunction with properties:
     Function: @sin
      Enabled: 1
    CacheSize: 10
>> b = a;
>> a.Enabled = 0;
>> b
b = 
  MemoizedFunction with properties:
     Function: @sin
      Enabled: 0
    CacheSize: 10
>> c = memoize(@sin)
c = 
  MemoizedFunction with properties:
     Function: @sin
      Enabled: 0
    CacheSize: 10
>> struct(c)
ans = 
  struct with fields:

            Function: @sin
             Enabled: 0
           CacheSize: 10
               Cache: [1x1 struct]
    PrivateCacheSize: 10
      TracingEnabled: 0
             Version: 1
       CachingPolicy: 'CB'
>> ans.Cache
ans = 
  struct with fields:
         Inputs: {}
        Nargout: []
        Outputs: {}
       HitCount: []
           Load: 0
      TotalHits: 0
    TotalMisses: 0




    _______________________________________________________

File Attachments:


-------------------------------------------------------
Date: Wed 30 Jun 2021 02:48:42 PM UTC  Name: memoize.zip  Size: 4KiB   By:
gyom

<http://savannah.gnu.org/bugs/download.php?file_id=51629>

    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?60860>

_______________________________________________
  Message sent via Savannah
  https://savannah.gnu.org/