| """ |
| Reconstruct a JSON |
| ================== |
| |
| Demonstrates the experimental text-reconstruction feature |
| |
| The Reconstructor takes a parse tree (already filtered from punctuation, of course), |
| and reconstructs it into correct text, that can be parsed correctly. |
| 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. |
| """ |
|
|
| import json |
|
|
| from lark import Lark |
| from lark.reconstruct import Reconstructor |
|
|
| from _json_parser import json_grammar |
|
|
| test_json = ''' |
| { |
| "empty_object" : {}, |
| "empty_array" : [], |
| "booleans" : { "YES" : true, "NO" : false }, |
| "numbers" : [ 0, 1, -2, 3.3, 4.4e5, 6.6e-7 ], |
| "strings" : [ "This", [ "And" , "That", "And a \\"b" ] ], |
| "nothing" : null |
| } |
| ''' |
|
|
| def test_earley(): |
|
|
| json_parser = Lark(json_grammar, maybe_placeholders=False) |
| tree = json_parser.parse(test_json) |
|
|
| new_json = Reconstructor(json_parser).reconstruct(tree) |
| print (new_json) |
| print (json.loads(new_json) == json.loads(test_json)) |
|
|
|
|
| def test_lalr(): |
|
|
| json_parser = Lark(json_grammar, parser='lalr', maybe_placeholders=False) |
| tree = json_parser.parse(test_json) |
|
|
| new_json = Reconstructor(json_parser).reconstruct(tree) |
| print (new_json) |
| print (json.loads(new_json) == json.loads(test_json)) |
|
|
| test_earley() |
| test_lalr() |
|
|
