natural language generation

git-svn-id: https://slps.svn.sourceforge.net/svnroot/slps@1035 ab42f6e0-554d-0410-b580-99e487e6eeb2

shared/python/NLG.py

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+#!/usr/local/bin/python
+# -*- coding: utf-8 -*-
+import os
+import sys
+import slpsns
+import random
+import elementtree.ElementTree as ET
+import BGF
+
+class NLGEngine:
+	def __init__(self,grammar):
+		self.g = grammar
+	def describeGrammar(self):
+		s = random.choice(('Here is a story about our grammar','Once upon a type there was a grammar'))
+		s += '. '+self.describeRoot(self.g.roots) + '\n\n'+self.describeProduction(self.g.prods[0],True)+'\n\n'
+		s += '\n\n'.join(map(lambda x:self.describeProduction(x,False),self.g.prods[1:]))
+		return s.replace(' ,',',').replace(' .','.').replace('  ',' ').strip()
+	def describeRoot(self,roots):
+		if len(roots)==0:
+			return 'There is no main nonterminal there. '
+		elif len(roots)==1:
+			return random.choice(('The main part of this grammar is '+self.describeNonterminal(roots[0]),'The grammar is ruled by '+self.describeNonterminal(roots[0])))+'. '
+		else:
+			return 'The grammar was ruled by '+', '.join(map(self.describeNonterminal,roots[:-1]))+'and '+self.describeNonterminal(roots[-1])+'. '
+	def describeProduction(self,p,first):
+		if p.label:
+			if first:
+				s = 'There is a rule called '
+			else:
+				s = random.choice(('There is also a rule called ','Another rule is called ','Consider a rule that goes by the name of ','Also, there is a rule titled '))
+			s += p.label+'. It is about '+self.describeNonterminal(p.nt)+', which consist'
+			if p.nt[-1] == 's':
+				s += ' of '
+			else:
+				s += 's of '
+		else:
+			s = self.describeNonterminal(p.nt).capitalize()+' consists of '
+		s += self.describeExpression(p.expr)
+		return s.strip()+'. '
+	def describeNonterminal(self,name):
+		if name[-1].lower() == 's':
+			s = ''
+		elif name[0].lower() in ('a','i','e','o','u','j','y'):
+			s = 'an '
+		else:
+			s = 'a '
+		return s+name.replace('_',' ').lower()+' '
+	def describeTerminal(self,name):
+		btype = {'(':('parenthesis ','round bracket','open bracket'),
+		')':('parenthesis ','open bracket','round bracket'),
+		'[':('square bracket','closed bracket'),
+		']':('square bracket','closed bracket'),
+		'{':('curly bracket','swirly bracket','birdie bracket','squiggly bracket','fancy bracket'),
+		'}':('curly bracket','swirly bracket','birdie bracket','squiggly bracket','fancy bracket'),
+		'<':('angle bracket','triangular bracket','diamond bracket','chevron','fish bracket'),
+		'>':('angle bracket','triangular bracket','diamond bracket','chevron','fish bracket')}
+		if name == ',':
+			return 'a comma '
+		elif name == '.':
+			return 'a dot '
+		elif name == '*':
+			return 'a star '
+		elif name == '+':
+			return 'a plus '
+		elif name == '-':
+			return random.choice(('a minus ','a dash '))
+		elif name == ':':
+			return 'a colon '
+		elif name == '&':
+			return 'an ampersand '
+		elif name == '#':
+			return random.choice(('a hash ','a sharp sign ','a number sign '))
+		elif name == ';':
+			return 'a semicolon '
+		elif name == ':=':
+			return 'an assignment sign '
+		elif name == '<=':
+			return 'a less than or equals to sign '
+		elif name == '>=':
+			return 'a greater than or equals to sign '
+		elif name == '=':
+			return 'an equals sign '
+		elif name in ('(','[','{','<'):
+			return 'a '+random.choice(('opening','left'))+' '+random.choice(btype[name])+' '
+		elif name in (')',']','}','>'):
+			return 'a '+random.choice(('closing','right'))+' '+random.choice(btype[name])+' '
+		elif name.isalpha() and name == name.upper():
+			return 'an uppercased keyword “'+name.lower()+'” '
+		else:
+			return 'a keyword “'+name+'” '
+	def describeSequence(self,a):
+		return 'followed by '.join(map(self.describeExpression,a))+' '
+	def describeSelectable(self,name,desc):
+		return 'something that we will call '+name+' but which is in fact '+desc+' '
+	def describeEpsilon(self):
+		return random.choice(('nothing','empty','an empty string','zilch'))+' '
+	def describeAny(self):
+		return random.choice(('anything','something unknown','some kind of string'))+' '
+	def describeOptional(self,desc):
+		return 'possibly '+desc
+	def describeExpression(self,e):
+		if e.wrapped.__class__.__name__ == 'Terminal':
+			return self.describeTerminal(e.wrapped.data)
+		elif e.wrapped.__class__.__name__ == 'Nonterminal':
+			return self.describeNonterminal(e.wrapped.data)
+		elif e.wrapped.__class__.__name__ == 'Sequence':
+			return self.describeSequence(e.wrapped.data)
+		elif e.wrapped.__class__.__name__ == 'Selectable':
+			return self.describeSelectable(e.wrapped.sel,self.describeExpression(e.wrapped.expr))
+		elif e.wrapped.__class__.__name__ == 'Optional':
+			return self.describeOptional(self.describeExpression(e.wrapped.data))
+		elif e.wrapped.__class__.__name__ == 'Epsilon':
+			return self.describeEpsilon()
+		elif e.wrapped.__class__.__name__ == 'Any':
+			return self.describeAny()
+		elif e.wrapped.__class__.__name__ == 'Empty':
+			return self.describeEmpty()
+		elif e.wrapped.__class__.__name__ == 'Plus':
+			return 'one or more occurrences of '+self.describeExpression(e.wrapped.data)
+		elif e.wrapped.__class__.__name__ == 'Star':
+			return 'zero or more occurrences of '+self.describeExpression(e.wrapped.data)
+		if True:
+			return "I'm at a loss of words when I need to talk about "+e.wrapped.__class__.__name__+'! '
+		elif e.wrapped.__class__.__name__ == 'Value':
+			return self.describeValue(e.wrapped)
+		elif e.wrapped.__class__.__name__ == 'Choice':
+			return self.describeChoice(e.wrapped)
+

topics/investigation/nlg/tell.py

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+#!/usr/local/bin/python
+import os,sys
+import elementtree.ElementTree as ET
+sys.path.append(os.getcwd().split('projects')[0]+'projects/slps/shared/python')
+import BGF, NLG
+
+if __name__ == "__main__":
+	if len(sys.argv) not in (2,3):
+		print 'This tool tells a story about a grammar.'
+		print 'Usage:'
+		print '      tell <bgf-input> [<text-output>]'
+		sys.exit(1)
+	bgf = BGF.Grammar()
+	bgf.parse(sys.argv[1])
+	storyteller = NLG.NLGEngine(bgf)
+	if len(sys.argv) == 2:
+		print storyteller.describeGrammar()
+	else:
+		story = open(sys.argv[2],'w')
+		story.write(storyteller.describeGrammar())
+		story.close()
+	sys.exit(0)