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diff --git a/docs/roadmap.md b/docs/roadmap.md index 0fa3933b..ea321761 100644 --- a/docs/roadmap.md +++ b/docs/roadmap.md @@ -3,7 +3,7 @@ English | [日本語](roadmap.ja.md) Open compiler work and language proposals, reviewed against the current -snapshots on 2026-11-01. These are future changes, not promises about the +snapshots on 2026-11-07. These are future changes, not promises about the language implemented by the tutorial. Language changes still need their own design decisions and chapter boundaries. @@ -13,13 +13,12 @@ design decisions and chapter boundaries. components, with `Var` in `parser/` and `IterPeeps` in `codegen/`. It is the workspace for further cleanup; Chapter 28b retains the preceding compiler. -Constructor completion now checks the helper Returns after parsing, with missing -fields retained in private memory instead of separate exit maps. -The [construction-group prototype](../chapter29/docs/construction-groups.md) -adds unfinished constructor parameters and inferred field requirements. Remaining -work includes contracts for reference paths, exported contracts for separate -compilation, and forward calls with unfinished arguments. A disabled completion -test records the existing `TOP`-marker/inlining failure beside nullable defaults. +Constructor completion now uses private-memory field types and the existing +TypeCheck walk, after Iter/Opto propagation. The +[incomplete-reference design](../chapter29/docs/construction-groups.md) uses a +partial qualifier plus forward field views for local read-only borrowers. +Inferred field requirements, nested guarantees, and imported construction +contracts remain longer-term proposals. Keep the recursive-descent path aligned with the grammar. Review moving `TYPES` to `CodeGen`. Consider whether an allocation-free use of try-with-resources makes keep/unkeep pairing clearer; @@ -30,6 +29,13 @@ implementation and tests are experiments, not part of Chapter 29's behavior. ## Compilation and optimization +### Better error messages + +Improve compiler diagnostics: identify the offending source expression, explain +what was expected and what was found, and point to relevant declarations or call +sites. Preserve useful source locations through optimization and imports, and +avoid cascading errors that obscure the original problem. + ### Phase ordering and incremental analysis Remaining work: @@ -161,19 +167,6 @@ remain legal. String spill fixtures with helpers outside `_String` accessing keep those fixtures unchanged. Validate native execution and imported source ownership alongside the access diagnostics. -### Constructor helpers and completion - -Local SSA field updates, including final fields, repeated assignments, and -loops, are implemented. The remaining question is broader: should constructors -be allowed to pass unfinished `self` to helpers that become safe after -inlining, and should completion checks wait until SCCP? - -Decide those rules before changing the current parser-time completion checks -and early-publication restrictions. Separate reading an initialized field of -an unfinished object from exposing that object to arbitrary code. The -construction/escape teaching boundary can then be reviewed against the chosen -semantics. - ### ELF visibility and unknown callers Escape analysis tracks functions reachable by unknown callers, while the ELF @@ -229,11 +222,27 @@ ownership, borrowing, cycles, and native retention. Compact storage alone does not establish those rules. Preserve static class images and explicit native boundary conversions when choosing the representation. -## Data and library proposals +## Longer-term language and library proposals These are language-design alternatives. The sketches below are not executable examples of the current Simple grammar. +### Inferred partial-initialization contracts — deferred + +Allow partial arguments to expose initialized fields, retain partial references, +and propagate nested initialization guarantees, while reserving final-field +writes to the original constructor. Cliff decided against implementing this +now (2026-11-07): tracing requirements through aliases, nested fields, forwarding, +recursive calls, and returned/stored references adds more infrastructure than +is justified for this feature alone. + +Revisit alongside a general backwards/liveness analysis, which may also serve +future memory management. The normal-type contract proposal and its unresolved +details are recorded in the +[construction notes](../chapter29/docs/construction-groups.md#deferred-field-aware-contracts-2026-11-07). +The forward-only prototype permits local reads of proven initialized fields; +it adds no inferred contracts. Keep the separate-compilation restriction meanwhile. + ### Automatic memory management Explore automatic memory reclamation with few explicit lifetime annotations, |