Sample
winnow 1.0.4: Distinguish winnow error handling paths where alt combinator discards deep branch errors in favor of the last branch unless cut_err is used, try_map failures yield recoverable Backtrack rather than fatal Cut, and ContextError formatting displays only the innermost label while InputError drops context annotations entirely
Verified sample for cargo winnow 1.0.4: Distinguish winnow error handling paths where alt combinator discards deep branch errors in favor of the last branch…
sha256:37c7408540f30c3e0ea78c7a69f7ddb967574c1c9fbfebcf11fbf25d3bbe07d5
This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured.
How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people.
MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
rust linux x64 rust rust cargo
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| rust 1 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-16 |
| rust 1 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-18 |
Case
HOW- Goal
- Distinguish winnow error handling paths where alt combinator discards deep branch errors in favor of the last branch unless cut_err is used, try_map failures yield recoverable Backtrack rather than fatal Cut, and ContextError formatting displays only the innermost label while InputError drops context annotations entirely
- Packages
- Symbols
-
- winnow::error::ContextError
- winnow::error::ErrMode
- winnow::error::InputError
- winnow::error::TreeError
- winnow::error::ParseError
- winnow::combinator::alt
- winnow::combinator::cut_err
- Environment
- rust
- Created
- 2026-08-16T12:43:07Z
Contract
- assert alt with ContextError discards a partial match in an earlier branch and returns the error and offset of the last evaluated branch, while cut_err prevents backtrack and preserves the deep failure site
- assert try_map produces ErrMode::Backtrack rather than Cut on external validation failure so alt continues trying subsequent branches
- assert TreeError preserves all failed branches of an alt in a hierarchical Alt structure rather than overwriting them with the last branch
- assert InputError ignores AddContext labels and records the remaining input slice, whereas ContextError formats the innermost StrContext::Label and all Expected tokens but renders empty if unannotated
- assert Parser::parse erases the ErrMode modal distinction into ParseError and reports the offset of trailing unconsumed input when the inner parser succeeds partially
Files
- Cargo.lock
- Cargo.toml
- NOTES.md
- csx.json
- src/lib.rs