September Morn Update

Task/Anagrams/Python/anagrams-4.py

@@ -0,0 +1,111 @@
+'''Largest anagram groups found in list of words.'''
+
+from os.path import expanduser
+from itertools import groupby
+from operator import eq
+
+
+# main :: IO ()
+def main():
+    '''Largest anagram groups in local unixdict.txt'''
+
+    print(unlines(
+        largestAnagramGroups(
+            lines(readFile('unixdict.txt'))
+        )
+    ))
+
+
+# largestAnagramGroups :: [String] -> [[String]]
+def largestAnagramGroups(ws):
+    '''A list of the anagram groups of
+       of the largest size found in a
+       given list of words.
+    '''
+
+    # wordChars :: String -> (String, String)
+    def wordChars(w):
+        '''A word paired with its
+           AZ sorted characters
+        '''
+        return (''.join(sorted(w)), w)
+
+    groups = list(map(
+        compose(list)(snd),
+        groupby(
+            sorted(
+                map(wordChars, ws),
+                key=fst
+            ),
+            key=fst
+        )
+    ))
+
+    intMax = max(map(len, groups))
+    return list(map(
+        compose(unwords)(curry(map)(snd)),
+        filter(compose(curry(eq)(intMax))(len), groups)
+    ))
+
+
+# GENERIC -------------------------------------------------
+
+# compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
+def compose(g):
+    '''Right to left function composition.'''
+    return lambda f: lambda x: g(f(x))
+
+
+# curry :: ((a, b) -> c) -> a -> b -> c
+def curry(f):
+    '''A curried function derived
+       from an uncurried function.'''
+    return lambda a: lambda b: f(a, b)
+
+
+# fst :: (a, b) -> a
+def fst(tpl):
+    '''First member of a pair.'''
+    return tpl[0]
+
+
+# lines :: String -> [String]
+def lines(s):
+    '''A list of strings,
+       (containing no newline characters)
+       derived from a single new-line delimited string.'''
+    return s.splitlines()
+
+
+# from os.path import expanduser
+# readFile :: FilePath -> IO String
+def readFile(fp):
+    '''The contents of any file at the path
+       derived by expanding any ~ in fp.'''
+    with open(expanduser(fp), 'r', encoding='utf-8') as f:
+        return f.read()
+
+
+# snd :: (a, b) -> b
+def snd(tpl):
+    '''Second member of a pair.'''
+    return tpl[1]
+
+
+# unlines :: [String] -> String
+def unlines(xs):
+    '''A single string derived by the intercalation
+       of a list of strings with the newline character.'''
+    return '\n'.join(xs)
+
+
+# unwords :: [String] -> String
+def unwords(xs):
+    '''A space-separated string derived from
+       a list of words.'''
+    return ' '.join(xs)
+
+
+# MAIN ---
+if __name__ == '__main__':
+    main()