Implement recovery for declaration parsing #689
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At the moment this doesn’t change anything because all places that call `eat` have previous checks that make sure the parser is currently positioned at the expected token. In the future, this will allow us to start parsing functions that `eat` a token at a different token and this function is responsible for eating all intermediate tokens until the expected one.
…entation This makes it easier to implement recovery in the future.
If the item is not an expression, we can try skipping more tokens to parse a declaration.
The token was mis-classified
If the current token is not the start of a declaration, check if we can consume unexpected tokens to reach the declaration’s introducer.
…t of a layout node This helps us produce better error messages for declaration recovery.
This makes it easier to implement recovery in the future.
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This has become part of my recovery backlog #718. I’ll open a new PR for that change once all the prerequisites have been merged. |
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Depends on #688
The basic idea is that
isStartOfDeclarationnow has arecoverargument and returnstrueif it’s possible to recover to a declaration. Other than that, we needed some recovery infrastructure. The productions themself only needed minor changes to continue along the right path and skip the unexpected tokens.