Octave containers.map not working inside member function - containers

Question

I have the following test code which just creates an empty hashmap (containers.map) and fills it up afterwards:
hashtable = containers.Map('KeyType','char','ValueType','double');
hashtable('test') = 1.0;
as long as I use it in my "main" file, everything works fine...
But if I copy these 2 lines into a member function of an self created class, there comes the error:
error: class not found: MyClassName
error: called from
myMemberFunction at line 15 column 31
line 15 is the line where "hashtable('test') = 1.0;" stands.
If I remove this one line, everything works fine again.
I absolutly don't understand, why the error sais, it can not find my class...
I tested my class and everything works perfectly.
I set up the class in the following way:
1: created a folder named: "#MyClassName"
2: created a constructor file named: "MyClassName"
3: added a constructor function named: "function obj = MyClassName(obj)"
4: created a member function file named: "myMemberFunction"
5: created a member function within this file: "function obj = myMemberFunction(obj)
If this code (the hashmap) stands within my constructor it works fine.
Only if it stands inside my memberfunction line 15 "hashtable('test') = 1.0;" makes the error.

Answer 1

tl;dr - replace
hashtable('test') = 1.0;
with
subsasgn( hashtable, substruct( '()', {'test'} ), 1.0 );
Not sure if this is intended behaviour, or a side-effect of containers.Map being a classdef defined class, and whether or not this is because old and new style classes don't play well with each other. May be worth submitting a bug for this. But, seems like the problem is because hashtable('test') is not parsed as intended inside the method - presumably instead of validly treating it as a 'referencing' operation, it treats it as a function call?
In the interest of completeness, here's an MVCE:
% #MyClassName/MyClassName.m
function obj = MyClassName(obj)
obj = struct('myfield', []);
obj = class(obj, 'MyClassName');
end
% #MyClassName/display.m
function display( Obj );
display( [inputname(1), '.myfield = '] );
display( get( Obj, 'myfield' ) );
end
% #MyClassName/get.m
function Out = get( Obj, Field )
Out = struct(Obj).(Field);
end
% #MyClassName/set.m
function Obj = set( Obj, Field, Val )
Obj = struct(Obj);
Obj.(Field) = Val;
Obj = class( Obj, 'MyClassName' );
end
% #MyClassName/myMemberFunction.m
function obj = myMemberFunction(obj)
hashtable = containers.Map('KeyType', 'char', 'ValueType', 'double');
subsasgn( hashtable, substruct( '()', {'test'} ), 1.0 );
obj = set( obj, 'myfield', hashtable );
end
In terminal:
octave:1> a = MyClassName();
octave:2> a = myMemberFunction(a);
octave:3> a
a.myfield =
containers.Map object with properties:
Count : 1
KeyType : char
ValueType : double