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class Random:
def __init__(self, seed):
self.sevenFive = 16807
self.twoThirtyone = 2147483647
self.newNum = seed
def next(self):
self.newNum = self.sevenFive*self.newNum % self.twoThirtyone
return self.newNum
def choose(self, limit):
return self.next()%limit
class Rule:
def __init__(self, left, right):
self.left = left
self.right = right
self.count = 1
def __repr__(self):
string = str(self.count)
string += " "
string += str(self.left)
string += " -> "
for n in range (0, len(self.right)):
string += self.right[n]
string += " "
return string
class Grammar:
def __init__(self, seed):
self.r = Random(seed)
self.dictionary = {}
def rule(self, left, right):
if left not in self.dictionary:
self.dictionary[left]=(Rule(left,right),)
else:
self.dictionary[left]+=(Rule(left, right),)
def generate(self):
if 'Start' in self.dictionary:
return self.generating(('Start',))
else:
raise RuntimeError
def select(self, left):
rules=self.dictionary[left]
total=0
c=0
#Some of the loops are probably not needed
for m in range (0, len(rules)):
total+=rules[m].count
index = self.r.choose(total)
for c in range (0, len(rules)):
index -= rules[c].count
if index<=0:
break
chosen = rules[c]
for n in range (0, len(rules)):
if rules[n] is not chosen:
rules[n].count+=1
return chosen.right
def generating(self,strings):
result=''
for n in range (0, len(strings)):
if strings[n] not in self.dictionary:
result += strings[n]
result += " "
else:
result += self.generating(self.select(strings[n]))
return result
G = Grammar(101)
G.rule('Noun', ('cat',)) # 01
G.rule('Noun', ('boy',)) # 02
G.rule('Noun', ('dog',)) # 03
G.rule('Noun', ('girl',)) # 04
G.rule('Verb', ('bit',)) # 05
G.rule('Verb', ('chased',)) # 06
G.rule('Verb', ('kissed',)) # 07
G.rule('Phrase', ('the', 'Noun', 'Verb', 'the', 'Noun')) # 08
G.rule('Story', ('Phrase',)) # 09
G.rule('Story', ('Phrase', 'and', 'Story')) # 10
G.rule('Story', ('Phrase', 'but', 'Story')) # 11
G.rule('Start', ('Story', '.')) # 12
for n in range (0,5):
print(G.generate())
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