feat: add unique to rusty iterator

benchmarks/__init__.py

@@ -6,6 +6,7 @@
     benchmark_more_itertools_flatten,
     benchmark_more_itertools_nth,
     benchmark_more_itertools_take,
+    benchmark_more_itertools_unique,
     benchmark_more_itertools_unzip,
     benchmark_rusty_iterators_cache_cycle,
     benchmark_rusty_iterators_copy_cycle,
@@ -17,6 +18,7 @@
     benchmark_rusty_iterators_nth,
     benchmark_rusty_iterators_sequence_wrapper,
     benchmark_rusty_iterators_take,
+    benchmark_rusty_iterators_unique,
     benchmark_rusty_iterators_unzip,
     benchmark_stdlib_count,
     benchmark_stdlib_filter,
@@ -29,6 +31,7 @@
     "benchmark_more_itertools_flatten",
     "benchmark_more_itertools_nth",
     "benchmark_more_itertools_take",
+    "benchmark_more_itertools_unique",
     "benchmark_more_itertools_unzip",
     "benchmark_rusty_iterators_cache_cycle",
     "benchmark_rusty_iterators_copy_cycle",
@@ -40,6 +43,7 @@
     "benchmark_rusty_iterators_nth",
     "benchmark_rusty_iterators_sequence_wrapper",
     "benchmark_rusty_iterators_take",
+    "benchmark_rusty_iterators_unique",
     "benchmark_rusty_iterators_unzip",
     "benchmark_stdlib_count",
     "benchmark_stdlib_filter",

benchmarks/scenarios.py

@@ -114,3 +114,13 @@ def benchmark_more_itertools_take(arg: Iterable[int]) -> None:
 @BenchmarkManager.register(arg=range(1_000_000))
 def benchmark_rusty_iterators_take(arg: Iterable[int]) -> None:
     _ = LIter.from_it(iter(arg)).take(500_000).collect()
+
+
+@BenchmarkManager.register(arg=range(1_000_000))
+def benchmark_rusty_iterators_unique(arg: Iterable[int]) -> None:
+    _ = LIter.from_it(iter(arg)).unique().collect()
+
+
+@BenchmarkManager.register(arg=range(1_000_000))
+def benchmark_more_itertools_unique(arg: Iterable[int]) -> None:
+    _ = list(mi.unique(arg))

rusty_iterators/core/interface.pxd

@@ -26,6 +26,7 @@ cdef class IterInterface:
     cpdef StepBy step_by(self, int step)
     cpdef object sum(self)
     cpdef Take take(self, int amount)
+    cpdef Unique unique(self)
     cpdef object unzip(self)
     cpdef Zip zip(self, IterInterface second)
 
@@ -93,6 +94,10 @@ cdef class Take(IterInterface):
     cdef int taken
     cdef int amount
 
+cdef class Unique(IterInterface):
+    cdef IterInterface it
+    cdef set used
+
 cdef class Zip(IterInterface):
     cdef IterInterface first
     cdef IterInterface second

rusty_iterators/core/interface.pyi

@@ -81,6 +81,7 @@ class IterInterface(Generic[T]):
     def step_by(self, step: int) -> StepBy[T]: ...
     def sum(self: IterInterface[T_addable]) -> T_addable: ...
     def take(self, amount: int) -> Take[T]: ...
+    def unique(self) -> Unique[T]: ...
     @overload
     def unzip(self: IterInterface[list[R]]) -> tuple[list[R], list[R]]: ...
     @overload
@@ -147,3 +148,7 @@ class Take(IterInterface[T]):
 @final
 class Zip(IterInterface[ZipItem[T, R]]):
     def __init__(self, first: IterInterface[T], second: IterInterface[R]) -> None: ...
+
+@final
+class Unique(IterInterface[T]):
+    def __init__(self, it: IterInterface[T]) -> None: ...

rusty_iterators/core/interface.pyx

@@ -120,6 +120,9 @@ cdef class IterInterface:
     cpdef Take take(self, int amount):
         return Take(self, amount)
 
+    cpdef Unique unique(self):
+        return Unique(self)
+
     cpdef object unzip(self):
         cdef list left = []
         cdef list right = []
@@ -571,3 +574,30 @@ cdef class Zip(IterInterface):
 
     cpdef object next(self):
         return (self.first.next(), self.second.next())
+
+@cython.final
+cdef class Unique(IterInterface):
+    def __cinit__(self, IterInterface it):
+        self.it = it
+        self.used = set()
+
+    def __str__(self):
+        return f"Unique(it={self.it})"
+
+    cpdef Unique copy(self):
+        cdef Unique obj
+
+        obj = Unique(self.it.copy())
+        obj.used = self.used.copy()
+
+        return obj
+
+    cpdef object next(self):
+        cdef object item
+
+        while True:
+            item = self.it.next()
+
+            if item not in self.used:
+                self.used.add(item)
+                return item

tests/types/verify_types.py

@@ -29,6 +29,7 @@
         Skip,
         StepBy,
         Take,
+        Unique,
         Zip,
     )
     from rusty_iterators.core.wrappers import IterWrapper, SeqWrapper
@@ -234,6 +235,14 @@ def verify_inspect_type() -> None:
     assert_type(it.next(), int)
 
 
+def verify_unique_type() -> None:
+    it = LIter.from_items(1, 2, 3).unique()
+
+    assert_type(it, Unique[int])
+    assert_type(it.next(), int)
+    assert_type(it.collect(), list[int])
+
+
 def verify_peekable_type() -> None:
     it = LIter.from_items(1, 2, 3).peekable()
 

tests/unit/sync/test_unique.py

@@ -0,0 +1,21 @@
+from rusty_iterators import LIter
+
+
+def test_unique_values() -> None:
+    it = LIter.from_items(1, 2, 1, 3, 4, 2, 5, 1, 2)
+
+    assert it.unique().collect() == [1, 2, 3, 4, 5]
+
+
+def test_unique_copy() -> None:
+    it = LIter.from_items(1, 2, 1, 3, 4, 2, 5, 1, 2).unique()
+    cp = it.copy()
+
+    it.next()
+
+    assert it.collect() == [2, 3, 4, 5]
+    assert cp.collect() == [1, 2, 3, 4, 5]
+
+
+def test_unique_empty_iterator() -> None:
+    assert LIter.from_items().unique().collect() == []