kopia lustrzana https://github.com/micropython/micropython-lib
78 wiersze
2.4 KiB
Python
78 wiersze
2.4 KiB
Python
"""JSON token scanner
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"""
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import re
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try:
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from _json import make_scanner as c_make_scanner
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except ImportError:
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c_make_scanner = None
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__all__ = ["make_scanner"]
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NUMBER_RE = re.compile(
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r"(-?(?:0|[1-9]\d*))(\.\d+)?([eE][-+]?\d+)?", (re.VERBOSE | re.MULTILINE | re.DOTALL)
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)
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def py_make_scanner(context):
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parse_object = context.parse_object
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parse_array = context.parse_array
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parse_string = context.parse_string
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match_number = NUMBER_RE.match
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strict = context.strict
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parse_float = context.parse_float
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parse_int = context.parse_int
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parse_constant = context.parse_constant
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object_hook = context.object_hook
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object_pairs_hook = context.object_pairs_hook
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memo = context.memo
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def _scan_once(string, idx):
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try:
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nextchar = string[idx]
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except IndexError:
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raise StopIteration
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if nextchar == '"':
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return parse_string(string, idx + 1, strict)
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elif nextchar == "{":
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return parse_object(
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(string, idx + 1), strict, _scan_once, object_hook, object_pairs_hook, memo
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)
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elif nextchar == "[":
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return parse_array((string, idx + 1), _scan_once)
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elif nextchar == "n" and string[idx : idx + 4] == "null":
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return None, idx + 4
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elif nextchar == "t" and string[idx : idx + 4] == "true":
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return True, idx + 4
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elif nextchar == "f" and string[idx : idx + 5] == "false":
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return False, idx + 5
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m = match_number(string, idx)
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if m is not None:
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integer, frac, exp = m.groups()
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if frac or exp:
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res = parse_float(integer + (frac or "") + (exp or ""))
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else:
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res = parse_int(integer)
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return res, m.end()
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elif nextchar == "N" and string[idx : idx + 3] == "NaN":
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return parse_constant("NaN"), idx + 3
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elif nextchar == "I" and string[idx : idx + 8] == "Infinity":
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return parse_constant("Infinity"), idx + 8
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elif nextchar == "-" and string[idx : idx + 9] == "-Infinity":
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return parse_constant("-Infinity"), idx + 9
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else:
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raise StopIteration
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def scan_once(string, idx):
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try:
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return _scan_once(string, idx)
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finally:
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memo.clear()
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return _scan_once
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make_scanner = c_make_scanner or py_make_scanner
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