Add ?. and ?[ optional-access operators#22
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What: - Add internal/optaccess: a token-level pre-parse rewrite that turns `obj?.field` into `__try_select__(obj, "field")` and `obj?[i]` into `__try_index__(obj, i)`. The walker matches balanced parens/brackets and treats earlier `?` tokens as continuation links so chained `a?.b?.c` rewrites cleanly. Strings, runes, and comments are not touched. - Wire optaccess into the Compile pipeline ahead of jsonlit and preprocessSource, so `?[1]` can carry the inner index expression through unmolested. - Register sentinel forms `__try_select__` / `__try_index__` in higher_order.go alongside the other special forms. Each form short-circuits on a nil receiver and treats missing-key / out-of-range as nil; wrong-kind type errors still surface. - Add language-level tests in optional_access_test.go (chained selects, fallback via ||, predicates, type-error propagation, string-literal preservation) and unit + fuzz tests in internal/optaccess. - Add fuzz seeds covering `?.` and `?[` to FuzzCompile / FuzzEval. - Update spec.md, llms.txt, and the higher-order-patterns and examples guides (plus their matching test) to use `find(...)?.x` instead of the unsafe `find(...).x`. Why: - `?.` plus operand-returning `||` plus `try` covers the same use cases as `??` without needing precedence-aware token rewriting. - The rewrite layer mirrors internal/jsonlit so the disambiguation logic stays simple and is reasoning about tokens, not strings.
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What
internal/optaccess: a token-level pre-parse rewrite that turnsobj?.fieldinto__try_select__(obj, "field")andobj?[i]into__try_index__(obj, i). The walker matches balanced parens/brackets and treats earlier?tokens as continuation links so chaineda?.b?.crewrites cleanly. Strings, runes, and comments are not touched.optaccessinto theCompilepipeline ahead ofjsonlitandpreprocessSource, so?[1]can carry the inner index expression through unmolested.__try_select__/__try_index__inhigher_order.go. Each form short-circuits on a nil receiver and treats missing-key / out-of-range asnil; wrong-kind type errors still surface asErrEvaluate.optional_access_test.go(chained selects, fallback via||, predicates, type-error propagation, string-literal preservation) plus unit + fuzz tests ininternal/optaccess.?.and?[toFuzzCompile/FuzzEval.spec.md,llms.txt, and the higher-order-patterns and examples guides (plus their matching test) to usefind(...)?.xinstead of the unsafefind(...).x.Why
?.plus operand-returning||plustrycovers the same use cases as??without needing precedence-aware token rewriting. The rewrite layer mirrorsinternal/jsonlitso the disambiguation logic stays simple and reasons about tokens, not strings.Test plan
go test ./...go test -race ./...go test -run=^$ -fuzz=FuzzCompile -fuzztime=20s .go test -run=^$ -fuzz=FuzzEval -fuzztime=20s .go test -run=^$ -fuzz=FuzzRewrite -fuzztime=20s ./internal/optaccess/