Initial data commit

Task/Binary-search/Python/binary-search-4.py

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+# findIndexBinary_ :: (a -> Ordering) -> [a] -> Maybe Int
+def findIndexBinary_(p):
+    def go(xs):
+        def bin(lo, hi):
+            if hi < lo:
+                return None
+            else:
+                mid = (lo + hi) // 2
+                cmpr = p(xs[mid])
+                return bin(lo, mid - 1) if -1 == cmpr else (
+                    bin(mid + 1, hi) if 1 == cmpr else (
+                        mid
+                    )
+                )
+        n = len(xs)
+        return bin(0, n - 1) if 0 < n else None
+    return lambda xs: go(xs)
+
+
+# COMPARISON CONSTRUCTORS ---------------------------------
+
+# compare :: a -> a -> Ordering
+def compare(a):
+    '''Simple comparison of x and y -> LT|EQ|GT'''
+    return lambda b: -1 if a < b else (1 if a > b else 0)
+
+
+# byKV :: (a -> b) -> a -> a -> Ordering
+def byKV(f):
+    '''Property accessor function -> target value -> x -> LT|EQ|GT'''
+    def go(v, x):
+        fx = f(x)
+        return -1 if v < fx else 1 if v > fx else 0
+    return lambda v: lambda x: go(v, x)
+
+
+# TESTS ---------------------------------------------------
+
+
+if __name__ == '__main__':
+
+    # BINARY SEARCH FOR WORD IN AZ-SORTED LIST
+
+    mb1 = findIndexBinary_(compare('mu'))(
+        # Sorted AZ
+        ['alpha', 'beta', 'delta', 'epsilon', 'eta', 'gamma', 'iota',
+         'kappa', 'lambda', 'mu', 'theta', 'zeta']
+    )
+
+    print (
+        'Not found' if None is mb1 else (
+            'Word found at index ' + str(mb1)
+        )
+    )
+
+    # BINARY SEARCH FOR WORD OF GIVEN LENGTH (IN WORD-LENGTH SORTED LIST)
+
+    mb2 = findIndexBinary_(byKV(len)(6))(
+        # Sorted by rising length
+        ['mu', 'eta', 'beta', 'iota', 'zeta', 'alpha', 'delta', 'gamma',
+         'kappa', 'theta', 'lambda', 'epsilon']
+    )
+
+    print (
+        'Not found' if None is mb2 else (
+            'Word of given length found at index ' + str(mb2)
+        )
+    )