v0.0.20 — Consolidation

Consolidation release

No new compiler features — this release focuses on documentation hygiene, spec correctness, and test coverage.

Fixed

• Spec @t notation: corrected 30 code blocks across 5 spec files where @T was incorrectly used in data constructor fields and effect operation signatures
• Stale README limitations: removed rows for closures (#27) and effect handlers (#28), closed in v0.0.18/v0.0.19
• Spec limitation tracking: created issues #50–#53 for all previously unlinked limitations in Chapter 11; added limitation label

Added

• 104 new tests (795 total, up from 691):
  • test_types.py — 55 tests for type operations
  • test_wasm.py — 22 tests for WASM internals
  • test_errors.py — 18 new tests for diagnostics
  • test_cli.py — 10 new tests for error paths

Changed

• Spec allowlist cleaned: 0 MISMATCH entries (was 30), 37 blocks parse OK (was 21)

v0.0.19: Effect handler compilation (C6j)

C6j: Effect Handler Compilation

Compile handle[State<T>] expressions to WASM via host imports.

Added

• State handler translation: handle[State<T>](@T = init) { get/put clauses } in { body } compiles by initializing state via state_put_T, then compiling body with get/put mapped to host imports
• Handler clauses serve as specifications (not compiled) — resume() calls describe the default State semantics, validated by type checker
• Effect discharge: pure functions containing handle[State<T>] are compilable — state imports registered by scanning function body for handle expressions
• Unsupported handlers (Exn, custom effects) cause function to be skipped with warning
• Reworked examples/effect_handler.vera: added test_state_init and test_put_get
• 14 new codegen tests (691 total)

Closes #28 · PR: #49

v0.0.18: Closure compilation (C6h)

C6h: Closure Compilation

Compile anonymous functions and closures to WASM via function tables and call_indirect.

Added

• Closure representation: heap-allocated struct [func_table_idx: i32, captures...] as i32 pointer
• Function table infrastructure: closure signature types, funcref table, element segments
• Closure lifting: anonymous functions compiled as module-level WASM functions with $env parameter
• Free variable capture: detect SlotRef nodes referencing outer-scope bindings
• apply_fn built-in emitting call_indirect
• Function type aliases resolved to i32 closure pointers
• Reworked examples/closures.vera with make_adder, apply, map_option
• 17 new codegen tests (677 total)

Closes #27 · PR: #48

v0.0.17: Generics monomorphization (C6i)

C6i: Generics Monomorphization

Compile forall<T> functions to WASM via monomorphization.

Added

• Collection pass: walk non-generic bodies to find calls to generic functions, infer type bindings
• AST substitution: create monomorphized FnDecl copies with type variables replaced
• Name mangling: identity + (Int,) becomes identity$Int
• Call rewriting: generic calls resolve to mangled names at WASM translation time
• FnCall type inference for if-branches and chained calls
• 17 new codegen tests (660 total)

Closes #29 · PR: #42

v0.0.16: Match expression codegen (C6g)

C6g: Match Expression Codegen

Compile MatchExpr AST nodes to WASM chained if-else cascades.

Added

• ADT tag dispatch: load tag from heap pointer, compare, branch
• Field extraction at computed offsets into locals
• Pattern types: ConstructorPattern, NullaryPattern, WildcardPattern, BindingPattern, BoolPattern, IntPattern
• Recursive if-else cascade with environment scoping per arm
• 20 new codegen tests (643 total)

Closes #26 · PR: #41

v0.0.15: ADT constructor codegen (C6f)

C6f: ADT Constructor Codegen

Compile ConstructorCall and NullaryConstructor AST nodes to WASM heap-allocated tagged unions.

Added

• Nullary constructors: alloc, store tag, return pointer
• Constructors with fields: alloc, store tag, store fields at computed offsets, return pointer
• Field offsets computed from concrete argument types (handles monomorphized generics)
• ADT types compile to i32 (heap pointer) in signatures and type inference
• 12 new codegen tests (623 total)

PR: #40

v0.0.14: Bump allocator infrastructure (C6e)

C6e: Bump Allocator Infrastructure

Heap allocation support for ADT constructor codegen.

Added

• $heap_ptr mutable global with 8-byte aligned bump allocation
• $alloc internal function
• ConstructorLayout dataclass: tag, field offsets, total size per constructor
• Allocator emitted only when user-declared ADTs are present
• 26 new codegen tests (611 total)

PR: #39

v0.0.13: State<T> WASM host imports (C6d)

C6d: State<T> WASM Host Imports

Compile get/put operations for State<T> effects as WASM host imports.

Added

• State<Int>, State<Nat>, State<Bool>, State<Float64> compile to typed host import pairs
• get(()) compiles to call $vera.state_get_T; put(x) compiles to call $vera.state_put_T
• Host runtime maintains mutable state cells per type
• execute() accepts optional initial_state and returns final state
• Mixed effects supported: effects(<State<Int>, IO>)
• 15 new codegen tests (585 total)
• examples/increment.vera now compiles and runs

PR: #38

v0.0.12: Match exhaustiveness checking (C6c)

C6c: Match Exhaustiveness Checking

Compile-time verification that match expressions cover all possible values.

Added

• ADT exhaustiveness: all constructors covered or catch-all present
• Bool exhaustiveness: both true and false covered
• Infinite type exhaustiveness: Int, String, Float64, Nat require wildcard
• Unreachable arm warnings
• 17 new type checker tests (570 total)

Closes #18 · PR: #37

v0.0.11: Callee precondition verification (C6b)

C6b: Callee Precondition Verification

Modular call-site contract checking — when function f calls function g, verify preconditions hold.

Added

• Callee precondition checking at call sites with Z3
• Callee postconditions assumed at call sites for symbolic reasoning
• Recursive functions now verify ensures() at Tier 1 instead of Tier 3 fallback
• CallViolation dataclass and diagnostics
• 13 new verifier tests (553 total)

Closes #19 · PR: #36