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"""
Simple JSON Parser
==================
The code is short and clear, and outperforms every other parser (that's written in Python).
For an explanation, check out the JSON parser tutorial at /docs/json_tutorial.md
(this is here for use by the other examples)
"""
import sys

from lark import Lark, Transformer, v_args

json_grammar = r"""
    ?start: value
    ?value: object
          | array
          | string
          | SIGNED_NUMBER      -> number
          | "true"             -> true
          | "false"            -> false
          | "null"             -> null
    array  : "[" [value ("," value)*] "]"
    object : "{" [pair ("," pair)*] "}"
    pair   : string ":" value
    string : ESCAPED_STRING
    %import common.ESCAPED_STRING
    %import common.SIGNED_NUMBER
    %import common.WS
    %ignore WS
"""


class TreeToJson(Transformer):
    @v_args(inline=True)
    def string(self, s):
        return s[1:-1].replace('\\"', '"')

    array = list
    pair = tuple
    object = dict
    number = v_args(inline=True)(float)

    null = lambda self, _: None
    true = lambda self, _: True
    false = lambda self, _: False


### Create the JSON parser with Lark, using the LALR algorithm
json_parser = Lark(json_grammar, parser='lalr',
                   # Using the standard lexer isn't required, and isn't usually recommended.
                   # But, it's good enough for JSON, and it's slightly faster.
                   lexer='standard',
                   # Disabling propagate_positions and placeholders slightly improves speed
                   propagate_positions=False,
                   maybe_placeholders=False,
                   # Using an internal transformer is faster and more memory efficient
                   transformer=TreeToJson())

	"""
	Simple JSON Parser
	==================

	The code is short and clear, and outperforms every other parser (that's written in Python).
	For an explanation, check out the JSON parser tutorial at /docs/json_tutorial.md

	(this is here for use by the other examples)
	"""
	import sys

	from lark import Lark, Transformer, v_args

	json_grammar = r"""
	?start: value

	?value: object
	\| array
	\| string
	\| SIGNED_NUMBER -> number
	\| "true" -> true
	\| "false" -> false
	\| "null" -> null

	array : "[" [value ("," value)*] "]"
	object : "{" [pair ("," pair)*] "}"
	pair : string ":" value

	string : ESCAPED_STRING

	%import common.ESCAPED_STRING
	%import common.SIGNED_NUMBER
	%import common.WS

	%ignore WS
	"""


	class TreeToJson(Transformer):
	@v_args(inline=True)
	def string(self, s):
	return s[1:-1].replace('\\"', '"')

	array = list
	pair = tuple
	object = dict
	number = v_args(inline=True)(float)

	null = lambda self, _: None
	true = lambda self, _: True
	false = lambda self, _: False


	### Create the JSON parser with Lark, using the LALR algorithm
	json_parser = Lark(json_grammar, parser='lalr',
	# Using the standard lexer isn't required, and isn't usually recommended.
	# But, it's good enough for JSON, and it's slightly faster.
	lexer='standard',
	# Disabling propagate_positions and placeholders slightly improves speed
	propagate_positions=False,
	maybe_placeholders=False,
	# Using an internal transformer is faster and more memory efficient
	transformer=TreeToJson())