I made a typo below, I did not mean to put [...] around the solution. But why Maple throws an error on this only?

restart;
ode:=diff(y(x),x) = exp(x)*sin(x)+y(x)*cot(x);
my_sol:=[sin(x)*(exp(x)+_C1)];
odetest( y(x)=my_sol,ode) assuming x::real

          Error, (in type/algext) too many levels of recursion

But on other ODE's, it works

restart;
ode:=diff(y(x),x) = y(x);
my_sol:=[_C1*exp(x)];
odetest( y(x)=my_sol,ode) assuming x::real

                [0]

I'll correct my type and remove the []. But the question is, should Maple have thrown an error? And why only on this one? Would this be considered a bug?

Removing the [] from the first example above, the error is gone and 0 is returned.

Maple 2019.1, Physics V 395 on windows 10

I thought I remembed how to do this once in Maple, or asking something like this here, but may be it was something similar. But I am not able to figure it now or remember.

Given an expression, I want to find all occuranes of a pattern in it.  Not just one.  So this is like using patmatch but over and over again untill all patterns found. I'll give an example to make it easy to explain.

Given

expr := y^2*sin(1/y) + y^(3/2) + y + x*y^7;

I want to find all patterns of form y^n  so the result should be 

{y^(3/2), y^7, y^2, 1/y, y}

This below is how it is done in Mathematica, but having hard time translating this code to Maple.

The last line below does the actual repeated pattern matching. That line was not written by me. It is something from Mathematica forum at stackexchange and I use it all the time and it works well.

ClearAll[x,y,n]
expr = y^2*Sin[1/y] + y^(3/2) + y + x*y^7;
pat = y^n_.;
Last@Reap[expr /. a : pat :> Sow[a], _, Sequence @@ #2 &]

I looked at hastype also. But hastype will only tell me if the pattern is there or not. May be I did not use it right.

restart;
expr := y^2*sin(1/y) + y^(3/2) + y + x*y^7;
hastype(expr,symbol^(anything));

Gives true

I tried patmatch, but again, it only find one:

restart;
expr := y^2*sin(1/y) + y^(3/2) + y + x*y^7;
if patmatch(expr,a::anything+y^(n::anything)+b::anything,'la') then
   assign(la);
   n;
fi;

And the above is not even robust for finding one. Since I have to change the pattern again to account for multiplication/addition cases between terms. 

Is it possible to do in Maple the same thing I show in Mathematica? I am sure it is possible, but can't now find the right function in Maple.

Maple 2019.1

I do not understand why the following is not working. I have a package which has a module inside it. The module is exported by the package.

Inside that module, there is a proc, which is also exported by the module.

So why can't one call the proc from outside the package? What Am I doing wrong? and how to correct it? I'd like to be able to call the proc directly. 

A:=module()
  option package;
  export B;
  B := module()
      export foo;

      foo:=proc()
           print("in foo");
      end proc;

  end module;
end module;   

Now when typing (A::B):-foo() Maple is not happy and says Error, module does not export `foo`

I tried different syntax from the above, but can't get it to work. For example A::B:-foo() gives Error, `B` does not evaluate to a module

Maple 2019.1

When making a proc that accepts positional and keyword based arguments, Maple allows the caller to put the keyword arguments before or after the positional arguments, or in between.

Is there a way to force the keyword arguments (if they are used) to only be placed after the (required) positional arguments during the call? 

An example will make it more clear. Given this proc

foo := proc(a::integer, b::integer, {c::integer:= 1, d::integer:= 1},$)
    print("a=",a," b=",b," c=",c," d=",d);
end proc:

It can be called as any one of these cases

foo(1,2);                                #case 1                                             
foo(1, 2,'c' = 1, 'd' = 2);              #case 2
foo('c' = 1, 1, 'd' = 2, 2);             #case 3
foo('c' = 1, 1, 2);                      #case 4
foo(1, 'c'=1, 2);                        #case 5
#more combinations possible

Is it possible to change how proc is defined, so that Maple will accept case1, and case 2 only in the above when the call is made and give an error otherwise?

i.e. only allow keyword arguments after all positional arguments.  I read https://www.maplesoft.com/support/help/Maple/view.aspx?path=argument_processing  and it says

After all arguments matching keyword parameters have been processed, matching of required positional and optional or expected ordered parameters is carried out

So from above, it looks like what I am asking for is not really possible. But I thought to ask, in case there is some way.

I find ability to put keyword arguments in the call anywhere and in-between required positional arguments confusing that is all.

Maple 2019.1

Is there a command or method in Maple to list all initially protected names?

This page https://www.maplesoft.com/support/help/Maple/view.aspx?path=UndocumentedNames list undocumented protected names, and this page https://www.maplesoft.com/support/help/Maple/view.aspx?path=initialconstants  lists initially known names, which I assume are all protected.

But what about a list of all protected names? sin,cos, eval, uneval, etc.. any name that can't be assigned to. In my search so far, I could not find how to find these names. There are 100's of such names. Can one get them all in a list to look at?

Using Maple 2019.1