Support logical values when using interactive

[Vipul-Cariappa]

reference: #4005

[certik]

In Fortran you want to print this as:

Suggested change

	std::cout << (r.b ? "True" : "False") << std::endl;
	std::cout << (r.b ? ".true." : ".false.") << std::endl;

[Vipul-Cariappa]

I am printing it based on what print function does

>>> print *, .true.
True

Do you want me to keep this existing implementation or change it to your suggestion?

[certik]

I see. Leave True then for now. We can change both later. In fact I think GFortran just prints T/F. I prefer True or .true., but for compatibility we'll at least have to add a compiler option to print just T/F. But that's a separate issue.

[certik]

I think we use 4 bytes integer as boolean, not 1 byte.

[certik]

Consequently, in LLVM we cannot fully determine the high level ASR type, since things are lowered (information got lost if we started with logical or integer).

So I think this function has to do its best with the information that it has, and somewhere else we need to use the ASR itself to determine what the return type should be and if it is compatible with the lowered type.

[Vipul-Cariappa]

Tried changing type->isIntegerTy(1) to type->isIntegerTy(4) the tests failed (New tests I added).

The isIntegerTy takes in Bitwidth, I don't think it is bytes.

[Vipul-Cariappa]

cc @Shaikh-Ubaid

[Shaikh-Ubaid]

Let's add two more tests in this:

• i = boolean operation on two boolean values
• i = function_that_returns_boolean_value()

[Shaikh-Ubaid]

Let's improve the tests. The rest of the things look good to me. Great work!

[certik]

@Vipul-Cariappa once it is ready, go ahead and click on "Ready for review".

[Vipul-Cariappa]

Tests fail. The reason is:

❯ lfortran
Interactive Fortran. Experimental prototype, not ready for end users.
LFortran version: 0.0.0
  * Use Ctrl-D to exit
  * Use Enter to submit
  * Use Alt-Enter or Ctrl-N to make a new line
    - Editing (Keys: Left, Right, Home, End, Backspace, Delete)
    - History (Keys: Up, Down)
>>> function is_even(n) result(result)                                                                                                             ┐
...   integer, intent(in) :: n                                                                                                                     │
...   logical :: result                                                                                                                            │
...   result = mod(n, 2) == 0                                                                                                                      │
... end function is_even                                                                                                                     5,21  ┘
>>>                                                                                                                                          1,1   ]
ASR verify pass error: Function is_even doesn't depend on _lcompilers_optimization_mod_i32 but is found in its dependency list.
 --> input:1:1 - 2:127
  |
1 |    
  |    ...
...
  |
2 |    
  | ...^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ failed here


Note: Please report unclear, confusing or incorrect messages as bugs at
https://github.com/lfortran/lfortran/issues.

lcompilers/lpython#2706 tries to resolves this.