feat: support existing io.print formatting

TODO.md

@@ -12,8 +12,8 @@ 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.
+native scalar/pointer `c_func` declarations include variadic calls and C integer
+promotions; 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.
@@ -82,6 +82,11 @@ aggregate copies and allocator failure/cleanup through both paths; native checks
 cover automatic integer/bool/enum/distinct/array/record keys, content-based strings
 and custom callbacks with the real C allocator. expected result types infer initializer
 types/callbacks, including automatic, string and custom maps.
+existing `io.print` expands constant formats and tuple fields, with exact boolean,
+integer, string, enum and distinct formatting through both paths. native float
+formatting uses imported `snprintf`; interpreter float formatting retains the FFI trap.
+character literals, multiline conditional branches, partial compile-time argument
+prefixes and checked `rem!` support the formatter without a replacement library.
 `unreachable` is a demanded source trap; terminal literal-true loops need no return.
 `compile_error!` retains owned user messages and skips unselected compile-time bodies.
 boolean and optional-capture `if ... else` expressions reuse checked matches for
@@ -111,9 +116,10 @@ needs records, pointers, generics and C calls.
 - [x] 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; `@hide:file` isolates private
-declarations from sibling files and import selection. other unsupported attributes
-are diagnosed. the scalar-function milestone did not
-include record fields or imported types; those now work for the record/tuple slice.
+declarations from sibling files and import selection. bare `@hide` and
+`@hide:package` retain sibling access but reject imports. unknown attributes diagnose.
+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
@@ -156,7 +162,7 @@ test discovery and FFI remain outside these completed slices.
   - [x] composed inline-match checkpoint: composed error sets expand remaining variants through interpreter/native execution, including nested/repeated/aliased enum, tagged-union and named struct members. all-void sets use one static tag capture; payload-bearing sets use exact immutable by-value payloads and optional static tags, including void members. catch captures, nested inline tag matches, generic calls, owned aggregate copies, deferred cleanup and error returns retain ordinary semantics. constant inputs and type-producing bodies select generated storage with cached nominal identity; struct variant names remain identifiers in generated constants rather than embedding declarations. invalid compositions/captures, narrow payload types, redundant arms, imported dependencies and repeatable compilation retain diagnostics and ownership. member discovery shares the type-control bound; pointer captures and metadata reflection remain open.
   - [x] type-metadata reflection checkpoint: `typeinfo!(T)` uses the actual `@std/meta` ABI to classify supported types and expose array child/length, immediate distinct backing, record names/tuple/layout and enum/record fields through interpreter/native execution. readonly owned metadata collections retain exact nominal/type leaves, ordinal indices, composed enum identity, checked projections, by-value iteration/copies and compile-time procedure boundaries. ordinary/inline matches select runtime bodies; reflected fields drive `field!`, generics and generated storage/defaults. arity/type/import/ABI failures, match/capture validation, bounds, readonly updates, runtime escape rejection, imported provenance, shared construction bounds and repeatable compilation retain diagnostics and ownership. existing `meta.EnumFieldStruct` and `enummap.EnumMap` generated storage are verified without replacement library code; full `enummap.init/get` is covered below, while general type-valued execution and broader constant materialization remain open.
   - [x] enum-map acceptance checkpoint: existing `enummap.init/get` run through interpreter/native execution with sparse/aliased/composed enum keys, absent entries and owned aggregate values. contextual `.tag` and aggregate arguments reuse key/value types inferred from rigid generated-map arguments; unresolved generics and rigid conflicts still diagnose. `some!` constructs exact, single-evaluation optional payloads and preserves nested present-null values through compile-time results, cache keys and generated defaults. concrete mutable runtime locals initialize from `undefined`, including nested record/array updates, pointer access and by-value copies; ordinary compile-time procedures materialize fully initialized storage and reject incomplete snapshots. native undefined storage is poison, not zeroed or per-leaf checked. `get` now explicitly returns `null` on lookup fallthrough, preserving the ordinary nonvoid return contract.
-  - [x] array-list acceptance checkpoint: existing `std/arraylist` and `std/mem` initialize, reserve/grow, append/pop/clear and release ordinary/aggregate/zero-sized storage without replacement library code. nested generic inference canonicalizes generated types through pointers and derives exact slice `.ptr` types; rigid conflicts remain diagnostic. `minval!`/`maxval!` preserve integer types and checked `divtrunc!` traps on zero and signed overflow through interpreter/native execution. file-local helpers retain real `@hide:file` visibility, newline `else` preserves match default arms, and repeated `_` parameters remain sinks. generated C records, nominal opaque pointers and foreign callbacks load from existing `ffi/c`; unused unsupported signatures neither diagnose nor emit external symbols, while demanded unsupported ABI/types diagnose. interpreter fixed-capacity allocator checks cover failure without losing storage and deferred error cleanup; native `mem.c_allocator` checks cover aggregate growth and over-aligned allocation/reallocation at `-O0`/`-O2`. arbitrary interpreter FFI, variadic/aggregate C calls and broader library acceptance remain open.
+  - [x] array-list acceptance checkpoint: existing `std/arraylist` and `std/mem` initialize, reserve/grow, append/pop/clear and release ordinary/aggregate/zero-sized storage without replacement library code. nested generic inference canonicalizes generated types through pointers and derives exact slice `.ptr` types; rigid conflicts remain diagnostic. `minval!`/`maxval!` preserve integer types and checked `divtrunc!` traps on zero and signed overflow through interpreter/native execution. file-local helpers retain real `@hide:file` visibility, newline `else` preserves match default arms, and repeated `_` parameters remain sinks. generated C records, nominal opaque pointers and foreign callbacks load from existing `ffi/c`; unused unsupported signatures neither diagnose nor emit external symbols, while demanded unsupported ABI/types diagnose. interpreter fixed-capacity allocator checks cover failure without losing storage and deferred error cleanup; native `mem.c_allocator` checks cover aggregate growth and over-aligned allocation/reallocation at `-O0`/`-O2`. variadic C calls and formatted IO are covered below; arbitrary interpreter FFI, aggregate C calls and broader metadata acceptance remain open.
   - [x] boolean conditional-expression checkpoint: `if (guard) then_value else else_value` reuses canonical matches through interpreter/native execution. guards evaluate once and only the selected expression executes; nested conditionals bind `else` to the nearest conditional. exact result types, aggregate copy isolation, contextual optional/fallible channels, direct `$()` values, constant-input procedures, generic branch selection and nested generated type positions retain existing checked execution. missing `else`, nonboolean guards and incompatible runtime branch types diagnose. optional captures, yielding value blocks, compound updates and bitwise operators are covered below.
   - [x] optional conditional-expression checkpoint: `if value |payload| then_value else else_value` reuses canonical presence matches through interpreter/native execution. single-evaluation guards and lazy branches preserve exact immutable by-value captures, nested optional presence, aggregate isolation and runtime pointer/callback/slice/zero-sized payloads. contextual optional/fallible results, constant-input procedures, generated types/defaults and explicit compile-time subject selection retain checked execution and owned payload snapshots. nonoptional guards, capture scope/shadowing, malformed captures, missing `else`, incompatible branches and compile-time overflow retain diagnostics. yielding value blocks are covered below; broader constant materialization remains open.
   - [x] yielding-block checkpoint: value blocks and `yield expression` produce exact/contextual results through interpreter/native execution, including conditional branches, match arms and catch handlers. nested value sources select the nearest target; ordinary blocks/loops preserve it. yielded aggregates snapshot before LIFO cleanup, successful yields skip `errdefer`, and return/error/break/continue retain enclosing targets. ordinary constants, generic branch specialization and type-producing blocks generate owned values, types, storage and defaults. missing operands/results, incompatible yields, capture mutation and outward cleanup transfers retain diagnostics and demand-driven traps; imported provenance and repeatable compilation are verified. labeled yields and value-producing loops remain outside this checkpoint.
@@ -176,7 +182,8 @@ test discovery and FFI remain outside these completed slices.
   - [x] metadata-input execution checkpoint: procedures with ordinary type-valued parameters execute entirely at compile time even when returning runtime-representable values. all inputs remain explicit constants; owned scalar/record/array/string results, recursive readonly metadata iteration, reflected field names/counts and private nominal leaves work through interpreter/native execution. plain/fallible `void` retain bare-return/fallthrough semantics; ordinary fallible results propagate through `try`/`catch` and run scoped `defer`/`errdefer`. runtime dependencies and incomplete payloads retain diagnostics; source/session disposal and repeat compilation preserve ownership. dependent signature parameters still require `$`; general type-valued execution, mutable metadata borrowing and broader constant materialization remain open.
   - [x] explicit metadata-local execution checkpoint: procedures with explicitly annotated type-valued locals execute entirely at compile time without metadata inputs or results. scalar inputs remain explicit constants; nested metadata records/arrays, undefined initialization, owned copies, checked field/index updates, loops, captures, recursion and scoped fallible cleanup reuse existing type-control execution through interpreter/native paths. runtime inputs and uninitialized leaves diagnose; ordinary unannotated local type aliases retain runtime parameters. imported private nominal leaves, source/session disposal and repeat compilation preserve ownership. inferred metadata-only locals are covered below; mixed runtime/type-valued execution, mutable metadata borrowing and broader constant materialization remain open.
   - [x] inferred metadata-local execution checkpoint: inferred mutable type bindings and metadata array/record/tuple locals select fully constant-input execution without metadata inputs, results or local annotations. literal/helper results, checked field/index/optional projections, yielding blocks and conditional/fallible selection preserve owned copies, nominal leaves, whole-value replacement, loops, recursion and scoped cleanup through interpreter/native execution. inferred array elements remain readonly; runtime inputs diagnose. ordinary local aliases and scalar metadata projections retain runtime parameters. ordinary fallible success/error snapshots use checked channel discrimination rather than assuming every payload carries a nominal type. imported private types, source/session disposal and repeat compilation preserve ownership. erased compile-time-only procedures cannot become runtime entries. mixed runtime/type-valued execution, mutable metadata borrowing and broader materialization remain open.
-  - [ ] remaining gate: general type-valued compile-time execution, broader constant materialization (including address-bearing untagged unions, nonnull data pointers and mutable slices), plus remaining existing-library acceptance for broader `meta` operations and `io.print`. formatting parsing and broader imported C-binding support may interleave with later gates.
+  - [x] formatted-IO acceptance checkpoint: existing `std/io.print` parses constant formats and expands tuple fields through interpreter/native execution. escaped braces, all integer bases/boundaries, booleans, strings/arrays, sparse/aliased enums, nested scalar distinct values, runtime arguments and computed formats retain exact output; short writes, zero progress, invalid callback counts and write errors retain checked propagation. malformed formats, wrong tuple/count/type inputs and unsupported specifiers diagnose. native `f64` default/decimal/scientific formatting uses imported variadic `snprintf` at `-O0`/`-O2`, while interpreter FFI remains a demanded trap. character literals preserve Unicode code points and byte escapes; newline-separated conditional branches and package-local visibility match Bro. partial compile-time prefixes infer remaining arguments without overriding explicit values; pure type builtins specialize guards. `rem!` preserves exact numeric types, signed-minimum remainder and checked zero divisors. immutable C byte-pointer coercions, borrowed pointer-to-array slices and optional presence retain mutability/nominal checks. the private format parser reuses inferred metadata-local execution and owned token initialization; inline metadata lookup and explicit predicate guards avoid runtime metadata storage. general type-valued execution, broader materialization and broader `meta` acceptance remain open.
+  - [ ] remaining gate: general type-valued compile-time execution, broader constant materialization (including address-bearing untagged unions, nonnull data pointers and mutable slices), plus remaining existing-library acceptance for broader `meta` operations. broader imported C-binding support may interleave with later gates.
 - [ ] remaining source constructs: multiline strings. boolean and optional-capture conditional expressions, yielding value blocks, `yield`, compound updates and bitwise operators are covered above. 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.