fix: Allow array comprehension syntax in comptime functions

guppylang/std/array.py

@@ -9,6 +9,7 @@
 from __future__ import annotations
 
 import builtins
+from types import GeneratorType
 from typing import TYPE_CHECKING, Generic, TypeVar, no_type_check
 
 from guppylang.decorator import guppy
@@ -71,6 +72,8 @@ def copy(self: array[T, n]) -> array[T, n]: ...
     def __new__(cls, *args: _T) -> builtins.list[_T]:  # type: ignore[no-redef]
         # Runtime array constructor that is used for comptime. We return an actual list
         # in line with the comptime unpacking logic that turns arrays into lists.
+        if len(args) == 1 and isinstance(args[0], GeneratorType):
+            return list(args[0])
         return [*args]
 
 

tests/integration/tracing/test_array.py

@@ -65,3 +65,12 @@ def main() -> int:
     validate(compiled)
     run_int_fn(compiled, 100)
 
+
+def test_comprehension(validate):
+    @guppy.comptime
+    def main() -> array[int, 5]:
+        xs = array(i for i in range(5))
+        assert xs == [0, 1, 2, 3, 4]
+        return xs
+
+    validate(guppy.compile(main))