[mypyc] Implement str.lower() and str.upper() primitive
#19375
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Jahongir-Qurbonov
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str.lower() and str.upper() primitive
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Thanks for the PR! Left some comments -- the semantics are pretty tricky, and we need to be careful to catch all special cases. I'd suggest running a test (doesn't need to be included in this PR necessarily) comparing upper/lower of all length-1 strings with Python semantics.
| #ifdef Py_UNICODE_TOLOWER | ||
| return Py_UNICODE_TOLOWER(ch); | ||
| #else | ||
| // fallback: no-op for non-ASCII if macro is unavailable |
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Is there a reason to expect that Py_UNICODE_TOLOWER is not available? We shouldn't break functionality if a dependency is missing -- it's better to fail compilation. It seems to me that the best option is to remove the #ifdef and assume ``Py_UNICODE_TOLOWER` is defined.
| if (ch < 128) { | ||
| return ascii_upper_table[ch]; | ||
| } | ||
| #ifdef Py_UNICODE_TOUPPER |
| assert "abc".lower() == "abc" | ||
| assert "AbC123".lower() == "abc123" | ||
| assert "áÉÍ".lower() == "áéí" | ||
| assert "😴🚀".lower() == "😴🚀" |
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Also test special cases (verify that this agrees with normal Python semantics):
'SS'.lower() == 'ss''Σ'.lower()'İ'.lower()(changes length!)
| assert "ABC".upper() == "ABC" | ||
| assert "AbC123".upper() == "ABC123" | ||
| assert "áéí".upper() == "ÁÉÍ" | ||
| assert "😴🚀".upper() == "😴🚀" |
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Also test special case (verify that this agrees with normal Python semantics):
'ß'.upper() == 'SS''ffi'.upper()(length increases!)
Add primitive for
str.lowerandstr.upper. Issue: mypyc/mypyc#1088