tut12 zwischenspeichern

Tutorium/tut12/src/functional.py

@@ -5,8 +5,8 @@ def map[T, R](func: Callable[[T], R], xs: Iterable[T]) -> Iterable[R]:
     return [func(x) for x in xs]
 
 
-def filter[T](func: Callable[[T], bool], xs: Iterable[T]) -> Iterable[T]:
-    return [x for x in xs if func(x)]
+def filter[T](predicate: Callable[[T], bool], xs: Iterable[T]) -> Iterable[T]:
+    return [x for x in xs if predicate(x)]
 
 
 def reduce[T](func: Callable[[T, T], T], xs: Iterable[T]) -> T:
@@ -35,21 +35,49 @@ def compose[T](*funcs: Callable[[T], T]) -> Callable[[T], T]:
     return reduce(lambda f, g: lambda n: f(g(n)), funcs)
 
 
-f: Callable[[int], int] = lambda n: n + 42
-g: Callable[[int], int] = lambda n: n ** 2
-h: Callable[[int], int] = lambda n: n - 3
+def poly(x: float) -> Callable[[float, float], Callable[[float], float]]:
+    return lambda a, b: lambda c: a * x ** 2 + b * x + c
 
-print(compose(f, g, h)(0))
+def main():
+    f: Callable[[int], int] = lambda n: n + 42
+    g: Callable[[int], int] = lambda n: n ** 2
+    h: Callable[[int], int] = lambda n: n - 3
 
-print(list(filter(lambda e: bool(e), [1, 2, 3, None, 5, 6])))
-print(list(filter(lambda e: not bool(e), [1, 2, 3, None, 5, 6])))
+    fhg: Callable[[int], int] = compose(f, g, h)
 
-print(list(map(lambda e: str(e), [1, 2, 3, 4, 5, 6, "hello_functional"])))
+    # f(g(h(0))) <=> ((0 - 3) ** 2) + 42 = 52
+    print(fhg(0))
+    print(compose(f, g, h)(0))
 
-print(list(
-    filter(lambda e: len(e) > 1,
-           map(lambda e: str(e),
-               [1, 2, 3, 4, "hello_world"]))))
+    print(list(filter(lambda e: bool(e), [1, 2, 3, None, 5, 6])))
+    print(list(filter(lambda e: not bool(e), [1, 2, 3, None, 5, 6])))
 
-print(list(filter(lambda e: isinstance(e, int), [1, 2, 3, "hello"])))
-print(list(flatten([[1, 2, 3], 4, [[5, 6], 7, [8, 9]]])))
+    print(list(map(lambda e: str(e), [1, 2, 3, 4, 5, 6, "hello_functional"])))
+
+    print(list(
+        filter(lambda e: len(e) > 1,
+               map(lambda e: str(e),
+                   [1, 2, 3, 4, "hello_world"]))))
+
+    print(list(filter(lambda e: isinstance(e, int), [1, 2, 3, "hello"])))
+    print(list(flatten([[1, 2, 3], 4, [[5, 6], 7, [8, 9]]])))
+
+    def add(a: int, b: int) -> int:
+        return a + b
+
+    add_but_variable: Callable[[int, int], int] = add
+    
+    print(add_but_variable(3, 2)) # 5
+    
+    add2: Callable[[int, int], int] = lambda x, y: x + y
+    
+    print(add2(2, 3))
+    
+    print((lambda x, y: x + y)(3, 4))
+    
+    print(reduce(lambda x, y: x + y, [1, 2, 3, 4])) # 10
+    
+    print(poly(3)(2, 3)(5))
+
+if __name__ == '__main__':
+    main()