101 lines
2.5 KiB
Python
101 lines
2.5 KiB
Python
'''Enumeration a-z'''
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from inspect import signature
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import enum
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# TEST ----------------------------------------------------
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def main():
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'''Testing particular instances of a general pattern:
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'''
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print(
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fTable(__doc__ + ':\n')(repr)(showList)(
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uncurry(enumFromTo)
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)([
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('a', 'z'),
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('α', 'ω'),
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('א', 'ת'),
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(1, 10),
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(round((5**(1 / 2) - 1) / 2, 5), 5),
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('🌱', '🍂')
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])
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)
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# GENERIC -------------------------------------------------
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# enumFromTo :: Enum a => a -> a -> [a]
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def enumFromTo(m):
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'''Enumeration of values [m..n]'''
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def go(x, y):
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t = type(m)
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i = fromEnum(x)
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d = 0 if t != float else (x - i)
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return list(map(
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lambda x: toEnum(t)(d + x),
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range(i, 1 + fromEnum(y))
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) if int != t else range(x, 1 + y))
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return lambda n: go(m, n)
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# fromEnum :: Enum a => a -> Int
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def fromEnum(x):
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'''Index integer for enumerable value.'''
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Enum = enum.Enum
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return ord(x) if isinstance(x, str) else (
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x.value if isinstance(x, Enum) else int(x)
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)
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# toEnum :: Type -> Int -> a
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def toEnum(t):
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'''Enumerable value from index integer'''
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dct = {
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int: int,
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float: float,
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str: chr,
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bool: bool
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}
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return lambda x: dct[t](x) if t in dct else t(x)
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# uncurry :: (a -> b -> c) -> ((a, b) -> c)
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def uncurry(f):
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'''A function over a tuple, derived from
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a vanilla or curried function.
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'''
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if 1 < len(signature(f).parameters):
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return lambda xy: f(*xy)
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else:
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return lambda xy: f(xy[0])(xy[1])
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# FORMATTING -------------------------------------------------
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# fTable :: String -> (a -> String) ->
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# (b -> String) -> (a -> b) -> [a] -> String
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def fTable(s):
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'''Heading -> x display function -> fx display function ->
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f -> xs -> tabular string.
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'''
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def go(xShow, fxShow, f, xs):
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ys = [xShow(x) for x in xs]
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w = max(map(len, ys))
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return s + '\n' + '\n'.join(map(
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lambda x, y: y.rjust(w, ' ') + ' -> ' + fxShow(f(x)),
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xs, ys
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))
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return lambda xShow: lambda fxShow: lambda f: lambda xs: go(
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xShow, fxShow, f, xs
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)
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# showList :: [a] -> String
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def showList(xs):
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'''Stringification of a list.'''
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return '[' + ','.join(str(x) for x in xs) + ']'
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# MAIN ---
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if __name__ == '__main__':
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main()
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