Added else if Conditional Statements to the Metal backend #34

[adityanarayanan343]

Added Support for else if in MetalParser

1. Grammar Update: Enhanced the parse_if_statement method to handle else if constructs in Metal syntax.

2. AST Update: Modified the Abstract Syntax Tree (AST) structure to support else if nodes, ensuring correct hierarchical representation of nested conditional logic.

3. Code Refactor: Refactored the parse_if_statement method to improve readability and maintainability while integrating else if logic.

Closes #34

[adityanarayanan343]

Can u please check what else is there to change in this code?

[samthakur587]

thanks @adityanarayanan343 for contributing here i'll happy to solve any query if you in understanding the code.

[samthakur587]

hii @adityanarayanan343 here you have added a condition for check else if token. you can directly add Token in TOKENS list and in this MetalLexer class the function tokenize will compile the string and find the if this token is in the code.

[samthakur587]

the changes in IfNode class is lgtm in ast.

[adityanarayanan343]

Can you check whether all the fixes you mentioned were addressed and please do tell if there were any other issues.

[samthakur587]

Can you check whether all the fixes you mentioned were addressed and please do tell if there were any other issues.

Hii @adityanarayanan343 sorry for late reply your changes are looking great 👍

One last thing can you please add a test for your else_if condition at metal backend you can find test files in tests folder. Before that pull the latest changes. 😄

Thanks
Sam

[samthakur587]

LGTM 🚀 waiting for tests to be added

[adityanarayanan343]

Sure thing @samthakur587 I will do it tomorrow morning and create a pull request.

[samthakur587]

Sure thing @samthakur587 I will do it tomorrow morning and create a pull request.

You can write all tests in this pr also just pull latest changes add test and push on this branch.

[adityanarayanan343]

Hi @samthakur587 I have done testing and added if-

else test case to the test codes please check and comment on any changes.
P.S: Attached Screenshot of getting all test cases passed

[samthakur587]

hii @adityanarayanan343 the tests are passing at metal codegen can you please have a look on this

---

self = <crosstl.src.backend.Metal.MetalCrossGLCodeGen.MetalToCrossGLConverter object at 0x7f10543909a0>
node = IfNode(condition=BinaryOpNode(left=MemberAccessNode(object=MemberAccessNode(object=input, member=position), member=x),...right=VectorConstructorNode(type_name=float2, args=['0.5', '0.5']))], else_body=None)], elif_bodies=[], else_body=None)
indent = 3, is_main = True

def generate_if_statement(self, node, indent, is_main):
    condition = self.generate_expression(node.condition, is_main)

    code = f"if ({condition}) {{\n"
    code += self.generate_function_body(node.if_body, indent + 1, is_main)
    code += "    " * indent + "}"
    for elif_node in node.elif_conditions:
        elif_condition = self.generate_expression(elif_node.condition, is_main)
        code += f" else if ({elif_condition}) {{\n"

      code += self.generate_function_body(elif_node.body, indent + 1, is_main)

E AttributeError: 'IfNode' object has no attribute 'body'

crosstl/src/backend/Metal/MetalCrossGLCodeGen.py:178: AttributeError
=========================== short test summary info ============================
FAILED tests/test_backend/test_metal/test_codegen.py::test_else_if - AttributeError: 'IfNode' object has no attribute 'body'
========================= 1 failed, 16 passed in 0.19s =========================

[adityanarayanan343]

Hi @samthakur587 ,

I think I have fixed the issue so can you please confirm the same thing and do comment on it.

Kudos,
Aditya

[samthakur587]

hii @adityanarayanan343 your tests are passing but not translating the correctly

shader main {
 
    // Vertex Shader
    vertex {
        input vec3 position;
        output vec2 vUV;
        void main() {
                        gl_Position = vec4(position, 1.0);
            if (position.x == position.y) {
                vUV = vec2(0.0, 0.0);
            } else if ([]) {
                vUV = vec2(1.0, 1.0);
            }
                    }
    }

    // Fragment Shader
    fragment {
        input vec2 vUV;
        output vec4 fragColor;
        void main() {
                        if (vUV.x == vUV.y) {
                fragColor = vec4(0.0, 1.0, 0.0, 1.0);
            } else if ([]) {
                fragColor = vec4(1.0, 0.0, 0.0, 1.0);
            }
                    }
    }
}

in else if condition the only [ ] is translated . can you please have a look on this . and can you please write a separate test for else_if not in if condition.

[adityanarayanan343]

Hi @samthakur587 I have added a separate case for if and if-else conditions please check this issue and check for any other issues. Also, can you show me where the else if issue [ ] is showing because I can't find it

Aditya

[adityanarayanan343]

Hi @vaatsalya123 can you check whether this issue has been fixed or not and can you please comment on it.

Thanks,
Aditya

[samthakur587]

hii @adityanarayanan343 if you run this command .

pytest -v tests/test_backend/test_metal/test_codegen.py -s

then you can see the generated code for your test and if you see for else_if test then in this the condition is generated empty .

[samthakur587]

hii @adityanarayanan343 we are very close to merging the PR . just make the last changes i requested .

[samthakur587]

hii @adityanarayanan343 can you have check on this bcz you are combining the elif_body and elif_condition in single list elif_condition which is not a good way to storing it in ast node . even when you have created the 2 different parameters in IFNode is elif_condition and elif_body.

[adityanarayanan343]

Hi @samthakur587, I think I have added the required changes please do check on it and comment on it.

[samthakur587]

hii @adityanarayanan343 great work i have fixed some small issues . now everything LGTM 🚀