mirror of https://github.com/lark-parser/lark.git
47 lines
1.3 KiB
Python
47 lines
1.3 KiB
Python
#
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# This example demonstrates an experimental feature: Text reconstruction
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# The Reconstructor takes a parse tree (already filtered from punctuation, of course),
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# and reconstructs it into correct text, that can be parsed correctly.
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# It can be useful for creating "hooks" to alter data before handing it to other parsers. You can also use it to generate samples from scratch.
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#
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import json
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from lark import Lark
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from lark.reconstruct import Reconstructor
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from .json_parser import json_grammar
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test_json = '''
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{
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"empty_object" : {},
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"empty_array" : [],
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"booleans" : { "YES" : true, "NO" : false },
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"numbers" : [ 0, 1, -2, 3.3, 4.4e5, 6.6e-7 ],
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"strings" : [ "This", [ "And" , "That", "And a \\"b" ] ],
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"nothing" : null
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}
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'''
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def test_earley():
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json_parser = Lark(json_grammar, maybe_placeholders=False)
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tree = json_parser.parse(test_json)
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new_json = Reconstructor(json_parser).reconstruct(tree)
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print (new_json)
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print (json.loads(new_json) == json.loads(test_json))
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def test_lalr():
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json_parser = Lark(json_grammar, parser='lalr', maybe_placeholders=False)
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tree = json_parser.parse(test_json)
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new_json = Reconstructor(json_parser).reconstruct(tree)
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print (new_json)
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print (json.loads(new_json) == json.loads(test_json))
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test_earley()
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test_lalr()
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