honey/TODO.md

self-hosting

• milestone: Honey compiles its production compiler, then that compiler compiles itself again and builds/runs the example programs.

current boundary

directory packages support file-local import namespaces and postfix declaration selection through the interpreter and native backend. concrete 8/16/32/64-bit integers, checked numeric conversions, records/tuples, construction/defaults, enums, distinct/alias types, overlapping untagged/tagged unions, field reads/writes and exhaustive statement/value matching work through both execution paths. source data pointers/references support aliasing, mutation, calls and aggregate storage; explicit callback signatures, many-pointer addition, mutable/sentinel slices, optionals and layout/cast/memory builtins work through both execution paths. native scalar/pointer c_func declarations support allocator-required libc calls; executed foreign calls remain diagnostic traps in the interpreter. explicit fallible channels, composed error sets, try/catch and scoped LIFO defer/errdefer run through both paths; source errors are values, not diagnostic traps or compiler infrastructure failures. cached generic specialization and type-producing procedures support explicit/inferred compile-time arguments and generated record/array storage through both paths. ordinary procedures can compute integer/boolean/string compile-time arguments using mutable locals, loops and recursive calls; general aggregate/type-valued execution, reflection and generic library acceptance remain open. the driver retains frontend storage and source provenance through @source/compilation, with compilation-wide AST node identities. file commands retain single-file behavior; directory commands compile the package's production files and load its dependencies in separate scopes.

completed milestone: scalar-function packages

verified: compile and run a small multi-file directory package importing a second package of scalar functions, through both the interpreter and native backend. using the existing standard library is a later acceptance gate: even std/mem needs records, pointers, generics and C calls.

• retain source/package identity and source ownership across the compilation; keep one identifier pool and unambiguous declaration IDs.
• load directory packages once per canonical path, with deterministic file discovery, package scopes and root-only entry selection. follow Bro's existing relative and project-root @ import rules; diagnose cycles rather than recurse indefinitely.
• finish postfix namespace selection and resolve file-local import aliases without injecting dependency names into the importing package; bare and aliased import declarations are already parsed for dependency discovery.
• reuse ordinary scalar signature checking, function values and IR calls for selected declarations; namespaces have no runtime representation.
• preserve originating filenames and spans in dependency diagnostics and native runtime traps; retain demand-driven diagnostic recovery.
• verify sibling source files, transitive/shared imports, same-spelled declarations in different packages, alias conflicts, missing packages/members, argument errors and dependency-file diagnostics. preserve existing single-file commands.

visibility follows Bro's public-by-default contract; unsupported visibility attributes must be diagnosed, never ignored. the scalar-function milestone did not include record fields or imported types; those now work for the record/tuple slice. test discovery and FFI remain outside these completed slices.

subsequent dependency gates

• concrete data models: required integer widths/conversions, records/tuples and construction, fields, enums, distinct/alias types, unions and matching. examples: source/lexer/token.hon, source/sema/resolve.hon, std/mem/mem.hon.
  • native integer widths (i8–i64, u8–u64, isize/usize) and checked explicit numeric conversions, including float truncation/range checks and integer-to-float rounding. preserve exact types through arrays, calls and range captures; retain strict implicit conversion rules.
  • records/tuples, typed/contextual/anonymous construction, field defaults and reads/writes, nested aggregate value copies, imported record types and constructors through interpreter/native execution.
  • nominal enums and distinct types, transparent declaration/type aliases, overlapping untagged/tagged unions, contextual payload construction, active-field checks and exhaustive scalar/enum/tagged-union matching through interpreter/native execution. pointer captures, inline specialization and yielding value blocks remain with their respective later gates; error-set composition is covered below.
• memory representation: source pointers/references, mutable and sentinel slices, optionals, layout/cast builtins and allocator-required libc calls. internal IR array addresses are not source pointers. examples: std/mem/mem.hon, std/arraylist/arraylist.hon.
  • source data pointers/references: @T/*T, mut, address-taking and dereference, pointer-aware fields/indexing, array .len/.ptr, readonly weakening, location equality, recursive pointer-linked records and shared pointees across interpreter/native calls and aggregate copies.
  • function-pointer signatures: explicit @proc(...) Result, structural signature checking, callbacks in parameters/results/records/arrays, vtable calls and imported signature aliases; many-pointer + usize arithmetic preserves pointee type, mutability, stride and location identity through interpreter/native execution.
  • mutable/sentinel slices with checked bounds, borrowed aliases and string views; optional values/pointers/callbacks, null checks, unwrap and conditional/loop captures; target layout, pointer/const casts and typed memory copy/set through interpreter/native execution. scalar/pointer C ABI declarations build/run allocator callbacks using malloc, realloc, free and posix_memalign; arbitrary interpreter FFI, generic standard-library compilation and native startup/IO remain with later gates.
• fallible results and cleanup: explicit T ! E, error-set composition, try/catch, defer/errdefer, error captures and matched error residuals through interpreter/native execution; infrastructure errors remain distinct from diagnostic traps. fallible void may complete on fallthrough; unhandled entry errors exit with status 1. inferred T! signatures and yielding catch blocks remain with inference/value-control-flow work. examples: source/main.hon, source/sema/check/check.hon.
• generic specialization and compile-time execution/reflection sufficient for existing ArrayList, hash maps, enummap, meta and io.print; include type/value parameters and compile-time generated storage.
  • specialization checkpoint: explicit/inferred type and integer/boolean/string/callback/null value parameters, cached concrete runtime calls, nominal type-producing procedures, generated record/array storage and recursive data pointers through interpreter/native execution. preserve declared value types, source diagnostics and repeatable compilation; runtime values cannot supply compile-time arguments.
  • compile-time execution checkpoint: ordinary procedure calls with constant inputs and integer/boolean/string results reuse checking, typed IR and bounded interpreter execution. mutable scalar locals, range/while loops, break/continue, nested/generic/recursive calls, exact numeric types, runtime traps and dependency-file provenance survive argument erasure through interpreter/native execution. runtime parameters and mutable global dependencies are rejected; recompilation retains no prior execution state.
  • remaining gate: general aggregate/type-valued compile-time execution, explicit compile-time expressions, compile-time branch/inline expansion and reflection (typeinfo!, field!, struct_type!, generated type/default arrays), plus existing-library acceptance. required collection/index iteration, expression-valued control flow, compound updates, formatting parsing and imported C-binding support may interleave with later gates.
• remaining source constructs: collection/index iteration, expression-valued control flow and yield, compound updates and multiline strings. examples: source/parser/parse.hon, source/llvm/runtime.hon.
• standard-library milestone: compile/run a multi-package program exercising existing allocation and IO, including error cleanup; no replacement miniature standard library.
• native driver integration: required C ABI declarations, process.Init startup arguments/IO, actual CLI exit statuses, file loading, temporary files and spawning Clang. Honey-generated programs currently accept only parameterless main and print its result; Bro's bootstrap startup support is not Honey backend support.
• self-hosting proof: bootstrap-built Honey builds the production compiler (excluding test-only imports); that executable rebuilds the compiler; the rebuilt compiler passes representative interpreter/native examples and CLI/error scenarios without Bro at runtime.

the gates may require interleaving (notably allocation, errors and generics). extend checking, IR and native emission together; accepting syntax alone does not complete a gate. additional targets, a package registry, a replacement linker and interpreter execution of arbitrary FFI are not prerequisites.