[Python] Add support for Array.takeWhile (#4297)

Author: dbrattli

pyproject.toml

@@ -47,28 +47,24 @@ reportUnusedVariable = false
 reportUnnecessaryIsInstance = true
 reportUnnecessaryComparison = true
 reportUnnecessaryCast = true
-reportPrivateUsage = false # Getters/setters reference private members from outside the class
+reportPrivateUsage = true
 reportImportCycles = true
 reportDuplicateImport = true
 reportConstantRedefinition = true
 reportOverlappingOverload = true
 reportInconsistentConstructor = true
 reportImplicitStringConcatenation = true
-
 pythonVersion = "3.12"
 typeCheckingMode = "standard"
 
 [tool.ruff]
+# Keep in sync with .pre-commit-config.yaml
 line-length = 120
+lint.ignore = []
+lint.select = ["E", "W",  "F", "I", "T", "RUF", "TID", "UP"]
 target-version = "py312"
 include =["*.py"]
 
-[tool.ruff.lint]
-select = ["E", "W",  "F", "I", "T", "RUF", "TID", "UP"]
-ignore = [
-    "F841" # Ignore unused variable warnings
-]
-
 [tool.ruff.lint.flake8-bugbear]
 # These Rust extension module types are immutable (frozen)
 extend-immutable-calls = [

src/Fable.Cli/CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 * [Python] Add `Array.skipWhile` support (by @dbrattli)
+* [Python] Add `Array.takeWhile` support (by @dbrattli)
 * [Python] Allow `IEnumerator_1` as base class to fix typing issues (by @dbrattli)
 * [Python] Add Pythonic import path syntax for relative imports (`.module`, `..parent`, `...grandparent`) (by @dbrattli)
 * [Python] Add `[<Py.DecorateTemplate>]` attribute for creating custom decorator attributes (by @dbrattli)

src/Fable.Compiler/CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 * [Python] Add `Array.skipWhile` support (by @dbrattli)
+* [Python] Add `Array.takeWhile` support (by @dbrattli)
 * [Python] Allow `IEnumerator_1` as base class to fix typing issues (by @dbrattli)
 * [Python] Add Pythonic import path syntax for relative imports (`.module`, `..parent`, `...grandparent`) (by @dbrattli)
 * [Python] Add `[<Py.DecorateTemplate>]` attribute for creating custom decorator attributes (by @dbrattli)

src/fable-library-py/fable_library/array_.py

@@ -115,6 +115,7 @@
 unzip = array.unzip
 copy = array.copy
 take = array.take
+take_while = array.take_while
 skip = array.skip
 skip_while = array.skip_while
 compare_to = array.compare_to
@@ -222,6 +223,7 @@
     "sum_by",
     "tail",
     "take",
+    "take_while",
     "transpose",
     "truncate",
     "try_find",

src/fable-library-py/fable_library/core/array.pyi

@@ -179,6 +179,7 @@ class FSharpArray[T](MutableSequence[T]):
     def sum_by[U](self, projection: Callable[[T], U], adder: IGenericAdder[U]) -> U: ...
     def tail(self, cons: FSharpCons[T] | None = None) -> FSharpArray[T]: ...
     def take(self, count: SupportsInt, cons: FSharpCons[T] | None = None) -> FSharpArray[T]: ...
+    def take_while(self, predicate: Callable[[T], bool], cons: FSharpCons[T] | None = None) -> FSharpArray[T]: ...
     def transpose(self, cons: FSharpCons[FSharpArray[T]] | None = None) -> FSharpArray[FSharpArray[T]]: ...
     def truncate(self, count: SupportsInt) -> FSharpArray[T]: ...
     def try_find(self, predicate: Callable[[T], bool]) -> T | None: ...
@@ -353,6 +354,9 @@ def sum[T](array: FSharpArray[T], adder: IGenericAdder[T]) -> T: ...
 def sum_by[T, U](projection: Callable[[T], U], array: FSharpArray[T], adder: IGenericAdder[U]) -> U: ...
 def tail[T](array: FSharpArray[T], cons: FSharpCons[T] | None = None) -> FSharpArray[T]: ...
 def take[T](count: SupportsInt, array: FSharpArray[T], cons: FSharpCons[T] | None = None) -> FSharpArray[T]: ...
+def take_while[T](
+    predicate: Callable[[T], bool], array: FSharpArray[T], cons: FSharpCons[T] | None = None
+) -> FSharpArray[T]: ...
 def transpose[T](
     array: FSharpArray[FSharpArray[T]] | Iterable[FSharpArray[T]], cons: FSharpCons[FSharpArray[T]] | None = None
 ) -> FSharpArray[FSharpArray[T]]: ...

src/fable-library-py/src/array.rs

@@ -1113,6 +1113,27 @@ impl FSharpArray {
         self.skip(py, count as isize, cons)
     }
 
+    #[pyo3(signature = (predicate, cons=None))]
+    pub fn take_while(
+        &self,
+        py: Python<'_>,
+        predicate: &Bound<'_, PyAny>,
+        cons: Option<&Bound<'_, PyAny>>,
+    ) -> PyResult<FSharpArray> {
+        let len = self.storage.len();
+        let mut count = 0;
+
+        while count < len {
+            let item = self.get_item_at_index(count as isize, py)?;
+            if !predicate.call1((item,))?.is_truthy()? {
+                break;
+            }
+            count += 1;
+        }
+
+        self.take(py, count as isize, cons)
+    }
+
     pub fn chunk_by_size(&self, py: Python<'_>, chunk_size: usize) -> PyResult<Self> {
         if chunk_size < 1 {
             return Err(PyErr::new::<exceptions::PyValueError, _>(
@@ -3234,6 +3255,17 @@ pub fn skip_while(
     array.skip_while(py, predicate, cons)
 }
 
+#[pyfunction]
+#[pyo3(signature = (predicate, array, cons=None))]
+pub fn take_while(
+    py: Python<'_>,
+    predicate: &Bound<'_, PyAny>,
+    array: &FSharpArray,
+    cons: Option<&Bound<'_, PyAny>>,
+) -> PyResult<FSharpArray> {
+    array.take_while(py, predicate, cons)
+}
+
 #[pyfunction]
 pub fn chunk_by_size(
     py: Python<'_>,
@@ -4551,6 +4583,7 @@ pub fn register_array_module(parent_module: &Bound<'_, PyModule>) -> PyResult<()
     m.add_function(wrap_pyfunction!(sum_by, &m)?)?;
     m.add_function(wrap_pyfunction!(tail, &m)?)?;
     m.add_function(wrap_pyfunction!(take, &m)?)?;
+    m.add_function(wrap_pyfunction!(take_while, &m)?)?;
     m.add_function(wrap_pyfunction!(transpose, &m)?)?;
     m.add_function(wrap_pyfunction!(try_find, &m)?)?;
     m.add_function(wrap_pyfunction!(try_find_back, &m)?)?;

tests/Python/TestArray.fs

@@ -735,6 +735,14 @@ let ``test Array.skipWhile works`` () =
     xs |> Array.skipWhile (fun x -> x < 6) |> equal [||]
     [||] |> Array.skipWhile (fun x -> x < 3) |> equal [||]
 
+[<Fact>]
+let ``test Array.takeWhile works`` () =
+    let xs = [|1; 2; 3; 4; 5|]
+    xs |> Array.takeWhile (fun x -> x < 3) |> equal [|1; 2|]
+    xs |> Array.takeWhile (fun x -> x < 1) |> equal [||]
+    xs |> Array.takeWhile (fun x -> x < 6) |> equal [|1; 2; 3; 4; 5|]
+    [||] |> Array.takeWhile (fun x -> x < 3) |> equal [||]
+
 // [<Fact>]
 // let ``test Array.sortDescending works`` () =
 //     let xs = [|3; 4; 1; -3; 2; 10|]