Unsupported type annotation: list

[Aasthaengg]

I have implemented functions for math.py which work when running with PYTHONPATH=src/runtime/ltypes python3 src/runtime/math.py but give Unsupported type annotation: list when running with ./src/bin/lpython src/runtime/math.py -o output && ./output.

Here's the sample fsum() function implementation.

def fsum(data: list) -> f64:
    """
    Sum of the elements of `data`.
    """
    sum: f64
    sum = 0.0

    i: i32
    for i in range(len(data)):
        sum += data[i]
    return sum

[certik]

Thanks for reporting this. Let's fix that.

[namannimmo10]

Yes, we need to add list as a supported type annotation, so that we can create an empty list like this:

(lp) namannimmo@srf lpython % cat t.py
def main():
  l: list
  l = []
  print(l)

main()

(lp) namannimmo@srf lpython % lpython t.py
semantic error: Unsupported type annotation: list
 --> t.py:2:3
  |
2 |   l: list
  |   ^^^^^^^ 

(lp) namannimmo@srf lpython % python t.py
[]

[namannimmo10]

In your implementation of fsum, list[f64] can be used.

[Smit-create]

Yes, we need to add list as a supported type annotation, so that we can create an empty list like this:

I don't think that's appropriate. In LPython we have everything with strict type notation. And just adding list annotation for creating an empty list does not seem to be useful since that won't have any lifeline in code as it won't perform any operations (neither we support list to list[anytype] conversion).

[czgdp1807]

@Aasthaengg Have you tried using list[f64] instead of just list? What's the output of that?

[certik]

Yes, list must specify the type of the elements, such as list[i32], or list[list[f64]]. Just list could be a shortcut for list[any], for a runtime dynamic type (each element a different type), but I would tackle this much later, if at all, for now let's focus on static types.

[Aasthaengg]

@czgdp1807 I still get semantic error: Unsupported type annotation: list when I make the argument as list[f64]

Here's the modified snippet -

def fsum(data: list[f64]) -> f64:
    """
    Sum of the elements of `data`.
    """
    sum: f64
    sum = 0.0

    i: i32
    for i in range(len(data)):
        sum += data[i]
    return sum

[Smit-create]

I still get semantic error: Unsupported type annotation: list when I make the argument as list[f64]

Please check again on the latest main branch. This was fixed in #493

[Aasthaengg]

I still get semantic error: Unsupported type annotation: list when I make the argument as list[f64]

Please check again on the latest main branch. This was fixed in #493

Alright, rebuilding it now.

[Smit-create]

Ah, I was talking just about --show-asr. LLVM backend doesn't support the list yet.

[certik]

Thanks @Smit-create for fixing it. This now works for lpython --show-asr:

def fsum(data: list[f64]) -> f64:
    """
    Sum of the elements of `data`.
    """
    sum: f64
    sum = 0.0

    i: i32
    for i in range(len(data)):
        sum += data[i]
    return sum

x: list[f64] = [1.0]
x.append(4.0)
print(fsum(x))

We now have to get it working for lpython --show-llvm.