ABC words: Difference between revisions
→{{header|Python}}: Added a functionally composed variant.
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' < unixdict.txt
</lang>
Or a functionally composed variant, with a predicate which takes a single recursive pass through the characters of each word:
<lang python>'''ABC Words'''
# isABC :: String -> Bool
def isABC(s):
'''True if s contains 'a', 'b' and 'c', with the
first occurrences of each in that order.
'''
return None != bind(
bind(
residue('a')('bc')(s)
)(
residue('b')('c')
)
)(
residue('c')('')
)
# residue Char -> String -> String -> Maybe String
def residue(c):
'''Any characters remaining in s after c, unless
c is preceded by excluded characters.
'''
def excluding(cs):
def go(s):
if s:
x = s[0]
return None if x in cs else (
s[1:] if c == x else go(s[1:])
)
else:
return None
return go
return excluding
# ------------------------- TEST -------------------------
# main :: IO ()
def main():
'''All words matching the isABC predicate
in a local copy of unixdict.txt
'''
for x in enumerate(
filter(
isABC,
readFile('unixdict.txt').splitlines()
),
start=1
):
print(x)
# ----------------------- GENERIC ------------------------
# bind (>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b
def bind(m):
'''Composition of a sequence of (a -> None | b) functions.
If m is None, it is passed straight through.
If m is x, the result is an application
of the (a -> None | b) function (mf) to x.
'''
def go(mf):
return m if None is m else mf(m)
return go
# readFile :: FilePath -> IO String
def readFile(fp):
'''The contents of any file at the path
derived by expanding any ~ in fp.
'''
with open(fp, 'r', encoding='utf-8') as f:
return f.read()
# MAIN ---
if __name__ == '__main__':
main()</lang>
{{Out}}
<pre>(1, 'aback')
(2, 'abacus')
(3, 'abc')
(4, 'abdicate')
(5, 'abduct')
(6, 'abeyance')
(7, 'abject')
(8, 'abreact')
(9, 'abscess')
(10, 'abscissa')
(11, 'abscissae')
(12, 'absence')
(13, 'abstract')
(14, 'abstracter')
(15, 'abstractor')
(16, 'adiabatic')
(17, 'aerobacter')
(18, 'aerobic')
(19, 'albacore')
(20, 'alberich')
(21, 'albrecht')
(22, 'algebraic')
(23, 'alphabetic')
(24, 'ambiance')
(25, 'ambuscade')
(26, 'aminobenzoic')
(27, 'anaerobic')
(28, 'arabic')
(29, 'athabascan')
(30, 'auerbach')
(31, 'diabetic')
(32, 'diabolic')
(33, 'drawback')
(34, 'fabric')
(35, 'fabricate')
(36, 'flashback')
(37, 'halfback')
(38, 'iambic')
(39, 'lampblack')
(40, 'leatherback')
(41, 'metabolic')
(42, 'nabisco')
(43, 'paperback')
(44, 'parabolic')
(45, 'playback')
(46, 'prefabricate')
(47, 'quarterback')
(48, 'razorback')
(49, 'roadblock')
(50, 'sabbatical')
(51, 'snapback')
(52, 'strabismic')
(53, 'syllabic')
(54, 'tabernacle')
(55, 'tablecloth')</pre>
=={{header|Raku}}==
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