22 lines
960 B
Markdown
22 lines
960 B
Markdown
# Block‑Postfix Catch Language Design (Draft)
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Goal
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- Make exception boundaries explicit by attaching `catch`/`cleanup` to standalone blocks.
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Design
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- Syntax: `{ body } catch (e) { handler } [cleanup { … }]` and `{ body } cleanup { … }`.
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- Policy: single catch (branch inside the catch); scope limited to the same block; no implicit propagation.
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- Static check (MVP): direct `throw` in a standalone block requires an immediate postfix `catch`.
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Implementation Notes
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- Parser (gated): normalize postfix to `ASTNode::TryCatch`.
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- Bridge(Result‑mode): ThrowCtx routes nested `throw` to the single catch; merge with PHI‑off.
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- Friendly errors: disallow top‑level leading `catch`/`cleanup`, and attaching to structural if/loop blocks.
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References
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- Parser: `src/parser/statements.rs`
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- Smokes: `src/tests/parser_block_postfix_{catch,errors}.rs`
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Open Questions
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- Multiple catch with type hierarchy; effects typing for static checks; formatter support.
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