示例
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
sha256:37c7408540f30c3e0ea78c7a69f7ddb967574c1c9fbfebcf11fbf25d3bbe07d5
PUBLISHED
L3_CONTRACT_PASS
MIT-0
案例
- 目标
- 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 HOW
- 包
- winnow 1.0.4
- 环境
- rust
- 创建时间
- 2026-08-16T12:43:07Z
常见的想当然
When an alt combinator fails on invalid input after partially matching an alternative, ContextError preserves the error details and byte offset from whichever branch parsed deepest.
这是本样本作者记下的、开发者或模型在此处通常会有的预期。下面的契约才是真正运行过的东西。
契约
- 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
文件
- Cargo.lock
- Cargo.toml
- NOTES.md
- csx.json
- src/lib.rs
下载已验证的构件 (tar.gz) — 契约实际运行的那些字节
原始种子者
验证回执
- rust 1 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · cargo@1 · 2026-08-16 · ed25519:d91480838ac982c9