CUSIP: Difference between revisions

Content added Content deleted
(→‎Python :: Composition of pure functions: Pylinted for Python 3, tidied, added a {works with} tag)
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===Composition of pure functions===
===Composition of pure functions===
{{Works with|Python|3.7}}
Composing a set of pure functions, including a number of general and reusable abstractions:
Composing a set of pure functions, including a number of general and reusable abstractions:
<lang python>from itertools import (cycle, islice, starmap)
<lang python>'''CUSIP'''

from itertools import (cycle, islice)
from functools import (reduce)
from functools import (reduce)
from operator import (add)
from operator import (add)
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def isCusip(dct):
def isCusip(dct):
'''Test for the validity of a CUSIP string in the
'''Test for the validity of a CUSIP string in the
context of a supplied dictionary of char values'''
context of a supplied dictionary of Char values.
'''
def go(s):
def go(s):
ns = [dct[c] for c in list(s) if c in dct]
ns = [dct[c] for c in list(s) if c in dct]
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sum(zipWith(
sum(zipWith(
lambda f, x: add(*divmod(f(x), 10))
lambda f, x: add(*divmod(f(x), 10))
)(cycle([stet, double]))(
)(cycle([identity, double]))(
take(8)(ns)
take(8)(ns)
)) % 10
)) % 10
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# main :: IO ()
# main :: IO ()
def main():
def main():
'''Tests'''
'''Test for validity as a CUSIP string'''

# cusipTest :: String -> Bool
cusipTest = isCusip(cusipCharDict())


print(
print(
tabulated('Valid as CUSIP string:')(
fTable(main.__doc__ + ':\n')(repr)(str)(
cusipTest
isCusip(cusipCharDict())
)([
)([
'037833100',
'037833100',
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)
)


⚫
# GENERIC -------------------------------------------------


# FORMATTING ----------------------------------------------

⚫
# fTable :: String -> (a -> String) ->
# (b -> String) -> (a -> b) -> [a] -> String
⚫
def fTable(s):
'''Heading -> x display function -> fx display function ->
f -> xs -> tabular string.
'''
⚫
def go(xShow, fxShow, f, xs):
ys = [xShow(x) for x in xs]
⚫
w = max(map(len, ys))
⚫
return s + '\n' + '\n'.join(map(
⚫
lambda x, y: y.rjust(w, ' ') + ' -> ' + fxShow(f(x)),
⚫
xs, ys
⚫
))
⚫
return lambda xShow: lambda fxShow: lambda f: lambda xs: go(
xShow, fxShow, f, xs
)


⚫
# GENERIC -------------------------------------------------


# double :: Num -> Num
# double :: Num -> Num
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# stet :: a -> a
# identity :: a -> a
def stet(x):
def identity(x):
'''The identity function.
'''The identity function.'''
The usual 'id' is reserved in Python.'''
return x
return x


⚫
# tabulated :: String -> (a -> b) -> [a] -> String
⚫
def tabulated(s):
'''heading -> function -> input List -> tabulated output string'''
⚫
def go(f, xs):
⚫
def width(x):
return len(str(x))
⚫
w = width(max(xs, key=width))
⚫
return s + '\n' + '\n'.join([
⚫
str(x).rjust(w, ' ') + ' -> ' + str(f(x)) for x in xs
⚫
])
⚫
return lambda f: lambda xs: go(f, xs)




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# zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
# zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
def zipWith(f):
def zipWith(f):
'''A list constructed by zipping with a
'''Zipping with a custom (rather than tuple) function'''
custom function, rather than with the
default tuple constructor.
'''
return lambda xs: lambda ys: (
return lambda xs: lambda ys: (
list(starmap(f, zip(xs, ys)))
map(f, xs, ys)
)
)


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main()</lang>
main()</lang>
{{Out}}
{{Out}}
<pre>Valid as CUSIP string:
<pre>Test for validity as a CUSIP string:

⚫
037833100 -> True
17275R102 -> True
'037833100' -> True
38259P508 -> True
'17275R102' -> True
594918104 -> True
'38259P508' -> True
⚫
'594918104' -> True
68389X106 -> False
'68389X106' -> False
68389X105 -> True</pre>
'68389X105' -> True</pre>


=={{header|Racket}}==
=={{header|Racket}}==
Retrieved from "https://rosettacode.org/wiki/CUSIP"