Eliminate dependency on nr-stream (#266)

* Eliminate dependency on `nr-stream`

* improve docstring

* add .envrc

* add changelog

.changelog/_unreleased.toml

@@ -15,3 +15,9 @@ id = "b7f209cb-7ff7-414d-b368-bde8cb57109d"
 type = "refactor"
 description = "move `kraken.std.git.gitignore.parser` to `kraken.common.gitignore`"
 author = "@NiklasRosenstein"
+
+[[entries]]
+id = "0a74ab07-f895-48e8-8842-6c5382ba8402"
+type = "refactor"
+description = "Eliminate `nr-stream` dependency"
+author = "@NiklasRosenstein"

.envrc

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+if which slap >/dev/null; then
+    eval "$(slap venv -a)"
+fi

kraken-build/pyproject.toml

@@ -45,7 +45,6 @@ httpx = "^0.27.0"
 keyring = "^25.0.0"
 networkx = "^3.1"
 nr-io-graphviz = "^0.1.1"
-nr-stream = "^1.1.0"
 packaging = "^23.1"
 pex = "^2.1.156"
 python = ">=3.10"

kraken-build/src/kraken/common/iter.py

@@ -0,0 +1,18 @@
+from collections.abc import Iterable
+from itertools import filterfalse, tee
+from typing import Callable, TypeVar
+
+T_co = TypeVar("T_co", covariant=True)
+
+
+def bipartition(predicate: Callable[[T_co], bool], it: Iterable[T_co]) -> tuple[Iterable[T_co], Iterable[T_co]]:
+    """
+    Partition a stream into two separate streams based on a predicate.
+
+    Returns:
+        A tuple of two iterators, where the first iterator contains only the elements for which the *predicate*
+        returned `False`, and the second iterator contains only the elements for which it returned `True`.
+    """
+
+    t1, t2 = tee(it)
+    return filterfalse(predicate, t1), filter(predicate, t2)

kraken-build/src/kraken/core/system/context.py

@@ -8,8 +8,6 @@
 from pathlib import Path
 from typing import Any, ClassVar, TypeAlias, TypeVar, overload
 
-from nr.stream import Stream
-
 from kraken.common import CurrentDirectoryProjectFinder, ProjectFinder, ScriptRunner
 from kraken.core.address import Address, AddressSpace, resolve_address
 from kraken.core.base import Currentable, MetadataContainer
@@ -303,11 +301,11 @@ def _resolve_single_address(
             address = relative_to.concat(address).normalize(keep_container=True)
 
         matches = list(resolve_address(space, self.root_project, address).matches())
-        tasks = Stream(matches).of_type(Task).collect()  # type: ignore[type-abstract]
+        tasks = [t for t in matches if isinstance(t, Task)]
         if set_selected:
             for task in tasks:
                 task.selected = True
-        projects = Stream(matches).of_type(Project).collect()
+        projects = [p for p in matches if isinstance(p, Project)]
         if projects:
             # Using the address of a project means we want to select its default tasks
             for proj in projects:

kraken-build/src/kraken/core/system/graph.py

@@ -7,9 +7,9 @@
 
 from networkx import DiGraph, restricted_view, transitive_reduction
 from networkx.algorithms import topological_sort
-from nr.stream import Stream
 
 from kraken.common import not_none
+from kraken.common.iter import bipartition
 from kraken.core.address import Address
 from kraken.core.system.executor import Graph
 from kraken.core.system.task import GroupTask, Task, TaskStatus, TaskTag
@@ -503,7 +503,7 @@ def ready(self) -> list[Task]:
         # NOTE(NiklasRosenstein): We don't need to return GroupTasks, we can mark them as skipped right away.
         #       In a future version of Kraken, we want to represent groups not as task objects, so this special
         #       handling code will be obsolete.
-        result, groups = map(lambda x: list(x), Stream(tasks).bipartition(lambda t: isinstance(t, GroupTask)))
+        result, groups = map(lambda x: list(x), bipartition((lambda t: isinstance(t, GroupTask)), tasks))
         for group in groups:
             self.set_status(group, TaskStatus.skipped())
         if not result: