o rZh @sZddlZddlZddlmZdddZddZddZd Zdd d Ze d kr+edSdS)N) NonterminalcCsF|s|}|durtdd}t||g|}|r!t||}|S)am Generates an iterator of all sentences from a CFG. :param grammar: The Grammar used to generate sentences. :param start: The Nonterminal from which to start generate sentences. :param depth: The maximal depth of the generated tree. :param n: The maximum number of sentences to return. :return: An iterator of lists of terminal tokens. N)startsysgetrecursionlimit _generate_all itertoolsislice)grammarrdepthniterrB/var/www/auris/lib/python3.10/site-packages/nltk/parse/generate.pygenerates  rc cst|r5z t||d|D]}t||dd|D]}||Vqq WdSty4}ztd|d}~wwgVdS)Nrz}The grammar has rule(s) that yield infinite recursion! Eventually use a lower 'depth', or a higher 'sys.setrecursionlimit()'.) _generate_onerRecursionError RuntimeError)r itemsr Zfrag1Zfrag2errorrrrr)s"  rccsT|dkr(t|tr"|j|dD]}t|||dEdHqdS|gVdSdS)Nr)lhsr) isinstancerZ productionsrrhs)r itemr prodrrrr9s  rz S -> NP VP NP -> Det N PP -> P NP VP -> 'slept' | 'saw' NP | 'walked' PP Det -> 'the' | 'a' N -> 'man' | 'park' | 'dog' P -> 'in' | 'with' cCsbddlm}td|ftt|t}tt||ddD]\}}td|d|fqdS)Nr)CFGz3Generating the first %d sentences for demo grammar:)r rz%3d. %s ) nltk.grammarrprint demo_grammarZ fromstring enumeraterjoin)Nrr r sentrrrdemoMs  r&__main__)NNN)r) rrrrrrrr!r&__name__rrrrs