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  • Damien George's avatar
    unix-cpy: Remove unix-cpy. It's no longer needed. · 65dc960e
    Damien George authored
    unix-cpy was originally written to get semantic equivalent with CPython
    without writing functional tests.  When writing the initial
    implementation of uPy it was a long way between lexer and functional
    tests, so the half-way test was to make sure that the bytecode was
    correct.  The idea was that if the uPy bytecode matched CPython 1-1 then
    uPy would be proper Python if the bytecodes acted correctly.  And having
    matching bytecode meant that it was less likely to miss some deep
    subtlety in the Python semantics that would require an architectural
    change later on.
    But that is all history and it no longer makes sense to retain the
    ability to output CPython bytecode, because:
    1. It outputs CPython 3.3 compatible bytecode.  CPython's bytecode
    changes from version to version, and seems to have changed quite a bit
    in 3.5.  There's no point in changing the bytecode output to match
    CPython anymore.
    2. uPy and CPy do different optimisations to the bytecode which makes it
    harder to match.
    3. The bytecode tests are not run.  They were never part of Travis and
    are not run locally anymore.
    4. The EMIT_CPYTHON option needs a lot of extra source code which adds
    heaps of noise, especially in compile.c.
    5. Now that there is an extensive test suite (which tests functionality)
    there is no need to match the bytecode.  Some very subtle behaviour is
    tested with the test suite and passing these tests is a much better
    way to stay Python-language compliant, rather than trying to match
    CPy bytecode.