84895f1a21
This patch improves parsing of floating point numbers by converting all the digits (integer and fractional) together into a number 1 or greater, and then applying the correct power of 10 at the very end. In particular the multiple "multiply by 0.1" operations to build a fraction are now combined together and applied at the same time as the exponent, at the very end. This helps to retain precision during parsing of floats, and also includes a check that the number doesn't overflow during the parsing. One benefit is that a float will have the same value no matter where the decimal point is located, eg 1.23 == 123e-2.
17 lines
522 B
Python
17 lines
522 B
Python
# test parsing of floats, requiring double-precision
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# very large integer part with a very negative exponent should cancel out
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print(float('9' * 400 + 'e-100'))
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print(float('9' * 400 + 'e-200'))
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print(float('9' * 400 + 'e-400'))
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# many fractional digits
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print(float('.' + '9' * 400))
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print(float('.' + '9' * 400 + 'e100'))
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print(float('.' + '9' * 400 + 'e-100'))
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# tiny fraction with large exponent
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print(float('.' + '0' * 400 + '9e100'))
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print(float('.' + '0' * 400 + '9e200'))
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print(float('.' + '0' * 400 + '9e400'))
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