Python: Allow use of match as an identifier
#19895
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This previously only worked in certain circumstances. In particular, assignments such as `match[1] = ...` or even just `match[1]` would fail to parse correctly. Fixing this turned out to be less trivial than anticipated. Consider the fact that ``` match [1]: case (...) ``` can either look the start of a `match` statement, or it could be a type ascription, ascribing the value of `case(...)` (a call) to the item at index 1 of `match`. To fix this, then, we give `match` the identifier and `match` the statement the same precendence in the grammar, and additionally also mark a conflict between `match_statement` and `primary_expression`. This causes the conflict to be resolved dynamically, and seems to do the right thing in all cases.
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This previously only worked in certain circumstances. In particular, assignments such as
match[1] = ...or even justmatch[1]would fail to parse correctly.Fixing this turned out to be less trivial than anticipated. Consider the fact that
can either look the start of a
matchstatement, or it could be a type ascription, ascribing the value ofcase(...)(a call) to the item at index 1 ofmatch.To fix this, then, we give
matchthe identifier andmatchthe statement the same precendence in the grammar, and additionally also mark a conflict betweenmatch_statementandprimary_expression. This causes the conflict to be resolved dynamically, and seems to do the right thing in all cases.