| .. _full-grammar-specification: |
| |
| Full Grammar specification |
| ========================== |
| |
| This is the full Python grammar, derived directly from the grammar |
| used to generate the CPython parser (see :source:`Grammar/python.gram`). |
| The version here omits details related to code generation and |
| error recovery. |
| |
| The notation used here is the same as in the preceding docs, |
| and is described in the :ref:`notation <notation>` section, |
| except for an extra complication: |
| |
| * ``~`` ("cut"): commit to the current alternative; fail the rule |
| if the alternative fails to parse |
| |
| Python mainly uses cuts for optimizations or improved error |
| messages. They often appear to be useless in the listing below. |
| |
| .. see gh-143054, and CutValidator in the source, if you want to change this: |
| |
| Cuts currently don't appear inside parentheses, brackets, lookaheads |
| and similar. |
| Their behavior in these contexts is deliberately left unspecified. |
| |
| .. literalinclude:: ../../Grammar/python.gram |
| :language: peg |
