Add support for list methods with Const

[kmr-srbh]

Fixes #2584

The following changes were made:

• list.append - throw a SemanticError stating changes not allowed
• list.remove - throw a SemanticError stating changes not allowed
• list.count - fetch the element count
• list.index - fetch the element index
• list.reverse - throw a SemanticError stating changes not allowed
• list.pop - throw a SemanticError stating changes not allowed
• list.clear - throw a SemanticError stating changes not allowed
• list.insert - throw a SemanticError stating changes not allowed

count()

l: Const[list[i32]] = [1, 2, 3, 4, 5, 1]
print(l.count(1))

(base) saurabh-kumar@Awadh:~/Projects/System/lpython$ ./src/bin/lpython ./examples/example.py
2

append()

l: Const[list[i32]] = [1, 2, 3, 4, 5, 1]
print(l.append(6))

(base) saurabh-kumar@Awadh:~/Projects/System/lpython$ ./src/bin/lpython ./examples/example.py
semantic error: cannot append element to a const list
 --> ./examples/example.py:8:7
  |
8 | print(l.append(6))
  |       ^^^^^^^^^^^ 


Note: Please report unclear or confusing messages as bugs at
https://github.com/lcompilers/lpython/issues.

Other functions work accordingly.

[kmr-srbh]

I am not sure why the tests fail. It passes when manually executing the file.

[anutosh491]

I guess you need to update the references.

[kmr-srbh]

I guess you need to update the references.

I have not written any new tests @anutosh491. These are the old ones which are failing.

I made changes to the count method. It says the test related to the method failed, but when I execute it manually on my PC, it passes .i.e prints True for all the asserts.

[Shaikh-Ubaid]

@kmr-srbh what specific test-case or example that fails with LPython (of current main branch) does this PR fix/support?

PS: Can you point to the issue that this PR fixes?

[kmr-srbh]

@kmr-srbh what specific test-case or example that fails with LPython (of current main branch) does this PR fix/support?

PS: Can you point to the issue that this PR fixes?

Please see #2567 (comment)

[Shaikh-Ubaid]

Why don't you create an issue first and list all the bugs related to List and List operations that you discovered? Share an example for each failure. Then in this PR specify exactly which bugs you have fixed (or are targeting to fix).

That would help highlight the contributions made and also make it simpler to review. Thanks!

[kmr-srbh]

That would help highlight the contributions made and also make it simpler to review. Thanks!

I am opening an issue. I will keep it in mind for future bugs. Thank you!

[Thirumalai-Shaktivel]

Please mark this PR ready for review once it is ready.

[kmr-srbh]

I am adding the tests @Thirumalai-Shaktivel and @Shaikh-Ubaid. In the meantime, I request you to review this. In accordance to the simplification advised by @Shaikh-Ubaid , I have simplified all such expressions. I have tested the changes locally.

I am doing the same for the dictionary PR too.

[Shaikh-Ubaid]

I shared two comments above. I think the PR is getting in shape. Thanks for working on this @kmr-srbh!

For each SemanticError() newly added in this PR, please add an error reference test.

[kmr-srbh]

For each SemanticError() newly added in this PR, please add an error reference test.

I am adding the tests in a while.

[kmr-srbh]

@Shaikh-Ubaid This PR is now ready.

[Shaikh-Ubaid]

I think the PR is in good direction. Great work @kmr-srbh!

[Shaikh-Ubaid]

Please mark it as "Ready for review" when ready.

[kmr-srbh]

I get this error when running the tests from ./integration_tests

from lpython import i32, list, str, Const


def test_const_list():
    CONST_INTEGER_LIST: Const[list[i32]] = [1, 2, 3, 4, 5, 1]

    assert CONST_INTEGER_LIST.count(1) == 2
    assert CONST_INTEGER_LIST.index(1) == 0

    CONST_STRING_LIST: Const[list[str]] = ["ALPHA", "BETA", "RELEASE"]
    assert CONST_STRING_LIST.count("ALPHA") == 1
    assert CONST_STRING_LIST.index("RELEASE") == 2


test_const_list()

code generation error: asr_to_llvm: module failed verification. Error:
Stored value type does not match pointer operand type!
  store %list* %const_list, %list* %CONST_INTEGER_LIST, align 8
 %list = type { i32, i32, i32* }Stored value type does not match pointer operand type!
  store %list.0* %const_list1, %list.0* %CONST_STRING_LIST, align 8
 %list.0 = type { i32, i32, i8** }

[Shaikh-Ubaid]

I get this error when running the tests from ./integration_tests

I attempted fixing it. Let's see if the CI passes.

[Shaikh-Ubaid]

I rebased this PR on main branch. Hence, to push to this branch further, you would need to first pull the changes from this branch with --rebase flag. For example,

git pull git@github.com:kmr-srbh/lpython.git const-list-attributes --rebase

or simply checkout a new copy of the remote branch and work on it if you are comfortable that way.

[Shaikh-Ubaid]

@kmr-srbh further tasks for you:

• Add support for list methods with Const #2570 (comment)
• Add support for list methods with Const #2570 (comment)

[Shaikh-Ubaid]

Please mark it as "Ready for review" when ready. I will do a final review then.

[Shaikh-Ubaid]

It looks great! Thanks for this! Amazing work!