a = 3
def foo():
a = 2
foo() # foo should set the outer a to 2
print a # so this should print '2'
Grammar -> split '| '(sentence -> (noun_phrase verb_phrase)
|noun_phrase -> (Article Noun)
|verb_phrase -> (Verb noun_phrase)
|Article -> the a
|Noun -> man ball woman table
|Verb -> hit took saw liked)
generate =: {[@P]->mapc r P; P:!rewrites->P,rand,r; P->[P]}
rewrites Category -> Grammar,{[@_ [!Category '-> @RHS] @_]->RHS}
from random import choice
def Dict(**args): return args
grammar = Dict(
S = [['NP','VP']],
NP = [['Art', 'N']],
VP = [['V', 'NP']],
Art = ['the', 'a'],
N = ['man', 'ball', 'woman', 'table'],
V = ['hit', 'took', 'saw', 'liked']
)
def generate(phrase):
"Generate a random sentence or phrase"
if isinstance(phrase, list):
return mappend(generate, phrase)
elif phrase in grammar:
return generate(choice(grammar[phrase]))
else: return [phrase]
def generate_tree(phrase):
"""Generate a random sentence or phrase,
with a complete parse tree."""
if isinstance(phrase, list):
return map(generate_tree, phrase)
elif phrase in grammar:
return [phrase] + generate_tree(choice(grammar[phrase]))
else: return [phrase]
def mappend(fn, list):
"Append the results of calling fn on each element of list."
return reduce(lambda x,y: x+y, map(fn, list))
>>> generate('S')
['the', 'man', 'saw', 'the', 'table']
>>> ' '.join(generate('S'))
'the man saw the table'
a = 3
def foo():
global a
a = 2
foo() # foo should set the outer a to 2
print a # so this should print '2'function f(args ...) body ... is not an alias for/equivalent to f = function(args ...) body ..., its anonymous functions are probably broken.a = 2 is declaring and initializing a variable or changing an already existent one. This will obviously lead to problems if you ever accidentally reuse the name of a global variable - forcing you to explicitly state you are using the global variable prevents this problem from occurring.
let/var keyword, with no keyword be ``use the outer variable''. global should just be removed because global variables are a bad idea the 80% of times.
insertEverywhere x xs = map (\(a,b) -> a ++ [x] ++ b) splits
where splits = map (flip splitAt xs) [0..length xs]
permutate [] = []
permutate [x] = [[x]]
permutate (x:xs) = permutate xs >>= insertEverywhere x
isSorted [] = True
isSorted [x] = True
isSorted (x:y:xs) | x <= y = isSorted (y:xs)
| otherwise = False
derpSort :: (Ord a) => [a] -> [a]
derpSort = head.filter isSorted.permutate