coop/rose-ash
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
fa99652970d7239087c5ae4e506e0fdd4704706b
rose-ash/plans/go-on-sx.md
giles fa99652970
Some checks failed
Test, Build, and Deploy / test-build-deploy (push) Failing after 30s
Details
go: eval.sx — range-over-{slice,map,chan} + 7 tests; break-env fix [nothing] 
Phase 5 cont. New go-eval-range-for handles the parser's :range-for
AST shape. Dispatches on the collection's runtime type:

  :go-slice  → bind index + element, iterate by position
  :go-map    → bind key + value, walk entries assoc list
  :go-chan   → bind value, drain until buffer empty (v0 limitation)

Each loop carries:
  - go-range-extend: handles 0/1/2-name binding patterns uniformly
  - go-range-body:   evaluates body whether it's a :block or other shape
  - per-collection loop helper: threads env, catches :break/:continue/
    :return-value/:eval-error sentinels

**Subtle break fix:** loops were previously returning the *pre-loop*
env when break fired, clobbering all assignments made in prior
iterations. Now returns the current iteration's input env (which
carries forward successful iterations' state). Patched for the three
range variants and for the regular for-loop where the same pattern
applied. The shape:

  (= r :break) env    ;; was: (= r :break) original-env

Tests:
  range: slice — sum of 1..5 = 15
  range: slice — key only (index)
  range: map — sum values
  range: channel — collect all buffered
  range: slice with break exits early
  range: slice with continue skips an element
  range: empty slice — body never runs
  range: chan + goroutine producer

runtime 26/26, total 483/483.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-27 22:09:46 +00:00

1055 lines
60 KiB
Markdown
Raw Blame History

# Go-on-SX — Go as an SX guest language
Port Go to SX as the **first static-typed, bidirectional-checked guest** in
the rose-ash language family. Goal isn't a production Go compiler; it's to
prove the substrate from a paradigm angle the existing eleven guests don't
cover, and to chisel out the lib/guest kits that statically-typed guests N+1
and N+2 will need.
Reference:
- `plans/lib-guest.md` — parent, chiselling discipline, two-language rule.
- `plans/lib-guest-scheduler.md` — sister kit; Go's scheduler pairs with
Erlang's. Extraction gated on this loop reaching Phase 5.
- `plans/lib-guest-static-types-bidirectional.md` — sister kit; Go's
checker pairs with a TBD second consumer. Extraction gated on this loop
reaching Phase 3.
- `plans/erlang-on-sx.md` — reference implementation for paradigm-port:
process model, BIF registry, hot reload, VM bytecode opcodes.
**Branch:** `loops/go` (loop-style workstream once kicked off). SX files via
`sx-tree` MCP only.
## Thesis — why Go
Eleven guests already live in `lib/`: apl, common-lisp, datalog, erlang,
forth, haskell, hyperscript, js, kernel, lua, minikanren, ocaml, prolog,
ruby, scheme, smalltalk, tcl. Every one is either **dynamically typed**
(most) or **HM-inferred** (haskell, ocaml). None exercise:
1. **Bidirectional static type checking** — annotation-driven, locally-
inferred, the dominant paradigm of modern statically-typed languages.
2. **Anonymous-channel concurrency** — Go's `chan` and `select`. Erlang has
addressed processes + mailboxes; Go has anonymous values + structural
pairing. Two different vocabularies for the same underlying scheduler
machinery.
3. **Structural interfaces** — `io.Reader` is "anything with this method
signature", not a declared subtype relationship. Different from Haskell
typeclasses (nominal), different from Lua duck typing (no declaration).
These three together make Go an unusually high-value port for proving SX.
If SX can host Go cleanly, it can host the next decade of mainstream
statically-typed languages (Rust, TS, Swift, Kotlin, Scala 3, Hack) because
they share these three properties.
Like Erlang-on-SX validated the actor model on the substrate, Go-on-SX
validates the goroutine model + bidirectional types.
## Non-goals (deliberate)
Out of scope. Reject feature requests for these without further consideration:
- **`unsafe` package.** Memory mucking. Skip entirely.
- **CGo.** C interop. Out of scope at every level.
- **Full `reflect`.** Provide enough for `fmt.Println` to render values;
reject the rest.
- **Build tags, modules, vendoring.** Treat source as monolithic. One
package per file, no real import resolution.
- **Production performance.** Conformance tests pass; benchmarks don't.
- **Garbage collection tuning.** SX's GC is what you get.
- **Race detector, escape analysis, inlining.** Out of scope.
- **`os`, `net/http`, full stdlib.** Provide a deliberately small slice
(Phase 8 below).
## Architecture sketch
```
Go source text
│
▼
lib/go/lex.sx — tokens; ASI; literals; operators
│ (consumes lib/guest/core/lex.sx)
▼
lib/go/parse.sx — AST: package/import/var/const/type/func/struct/
│ interface; expressions; statements
│ (consumes lib/guest/core/pratt.sx + ast.sx)
▼
lib/go/types.sx — bidirectional type checker. Synth + check judgments;
│ structural interface satisfaction; pluggable subtype
│ (INDEPENDENT — no lib/guest/static-types-bidirectional
│ yet; this loop builds the first consumer)
▼
lib/go/eval.sx — tree-walk evaluator on CEK. Variables as mutable cells;
│ slices = (length, capacity, backing-vector); maps =
│ SX dict; defer stack per frame.
▼
lib/go/sched.sx — goroutine scheduler + channels + select
│ (INDEPENDENT — no lib/guest/scheduler yet; this loop
│ builds the first consumer)
▼
lib/go/std/ — minimal stdlib slice (fmt, strings, strconv, sync,
time, errors)
```
Semantic mappings (operational):
- `go fn(args)` → `task-spawn` on the local scheduler.
- `ch <- v` → `task-block` with predicate "receiver waiting on ch".
- `v := <-ch` → `task-block` with predicate "sender waiting on ch".
- `select { case ... }` → `task-block` with predicate "any case ready".
- `defer fn()` → push thunk onto per-frame defer stack; runs LIFO on
return or panic.
- `panic(v)` → raise SX exception; deferred fns run while unwinding.
- `recover()` → CEK exception capture inside a deferred fn.
- `interface{T}` → type-check matches structurally against T's method
set; at runtime, the value carries its concrete-type metadata.
- `struct{...}` → SX dict + type tag; methods are functions in the type's
method table.
- `*T` (pointer) → mutable cell (Common Lisp port did the same).
- `[]T` (slice) → triple (length, capacity, backing-vector).
- `map[K]V` → SX dict; iteration order spec-undefined (v1 = sorted for
determinism — programs that depend on indeterminism fail loudly, which
is a feature not a bug).
## Conformance scoreboard
Following `lib/erlang/scoreboard.json` precedent. Add
`lib/go/scoreboard.json` on first iteration; populate as suites land.
Suites planned:
| Suite | Tests target | What it covers |
|---|---|---|
| `lex` | 50+ | Keywords, operators, literals, ASI |
| `parse` | 80+ | All statement & expression shapes |
| `types` | 90+ | Synth, check, interface satisfaction, generics |
| `eval` | 100+ | Tree-walk over typed AST |
| `runtime` | 60+ | Goroutines, channels, select, close |
| `stdlib` | 40+ | fmt, strings, strconv, sync, time, errors |
| `e2e` | 10+ | Complete representative programs |
## Phasing — one feature per commit
Loop-style. Each phase: implement → test → commit → tick `[ ]` → append
Progress-log line → push `origin/loops/go`.
### Phase 1 — Tokenizer (`lib/go/lex.sx`) ✅
- [x] Scaffold + scoreboard + conformance runner (consumes lib/guest/lex.sx)
- [x] Identifiers + 25 keywords
- [x] Decimal integer literals
- [x] Interpreted string literals `"..."` with `\n \t \r \\ \" \'` escapes
- [x] Rune literals `'x'` (single char + simple escapes)
- [x] Line + block comments (block w/ newline triggers ASI)
- [x] Common operator/punct set incl. `:= <- ++ -- == != <= >= && || ...`
- [x] **Automatic semicolon insertion** (Go spec § Semicolons) — newline,
EOF, and block-comment-with-newline trigger `;` after
ident/int/string/rune/{break,continue,fallthrough,return}/{++,--,),],}}.
- [x] Float / imaginary literals (decimal floats: `3.14 .5 1. 1e10 1.5e-3`;
imag: `2i 3.14i 1e2i`; hex floats `0x1.fp0` deferred)
- [x] Raw string literals `` `...` `` (multi-line, no escape processing,
`\r` stripped per Go spec § String literals; same `"string"` type
as interpreted strings)
- [x] Hex/octal/binary integer literals (0x… 0o… 0b…) + underscores
(legacy 0123 octal also accepted; consumes lex-hex-digit?)
- [x] Full operator set audit (47 distinct per Go spec, plus `~` for
generics type-sets). Exhaustive coverage tests in `op-audit:` block.
- **Acceptance:** lex/ suite at 50+ tests. Current: 129/129. **Phase 1
done** — hex floats deferred (rare). Move to Phase 2 next.
### Phase 2 — Parser (`lib/go/parse.sx`) ✅
- [x] Parser scaffold + Go operator-precedence table (entry shape from
`lib/guest/pratt.sx`) + primary expressions (int/float/imag/string/
rune/ident → ast-literal / ast-var via `lib/guest/ast.sx`).
- [x] Binary operators (Pratt precedence climbing using `pratt-op-lookup`
+ Go precedence table). Operator app emitted as
`(ast-app (ast-var OP) [LHS RHS])`; left-assoc raises right-min by 1.
- [x] Unary operators (`+x`, `-x`, `!x`, `^x`, `*p`, `&v`, `<-ch`).
`gp-parse-unary` recursive, sits between `gp-parse-expr` and
`gp-parse-primary`; right-associative chains (`!!x`).
- [x] Function calls `f(a, b)` (canonical `ast-app`) and member access
`x.field` (Go-specific `(list :select OBJ "field")` — the AST kit
doesn't ship a selector node; this is a sister-plan-static-types
data point about what the canonical AST is missing).
- [x] Index `x[i]` and slice `x[a:b]`/`x[a:b:c]`. Go-specific
`(list :index OBJ IDX)` and `(list :slice OBJ LOW HIGH MAX)`
(LOW/HIGH/MAX may be nil) — kit lacks both. Permissive parser
accepts `a[1::3]` (strict Go rejects, but type phase can enforce).
- [x] Type assertion `v.(T)`. `(list :assert OBJ TYPE)`. Includes a
minimal `gp-parse-type` (named / qualified `pkg.T` / pointer
`*T` / `**T`); full type grammar still pending below.
- [x] Type expressions: **slice `[]T`, array `[N]T`, map `map[K]V`, chan
`chan T` / `chan<- T` / `<-chan T`, pointer `*T`, named `T`,
qualified `pkg.T`, func `func(...) ...`, struct `struct{...}` with
shared-type field rows (`x, y int`), interface `interface{...}`
with methods + embedded interfaces (named and qualified)** all
done — kit has no type primitives. Field tags, struct embeds,
variadic, named func-params, Go 1.18 type sets, generics deferred.
- [x] Composite literals: `T{...}`, `[]T{...}`, `[N]T{...}`,
`map[K]V{...}`, `pkg.T{...}`, nested. Positional and keyed
(`X: 1, Y: 2`) elements. AST `(list :composite TYPE-OR-EXPR ELEMS)`;
elements are exprs or `(list :kv KEY VALUE)`. Note: in statement
context (e.g. `if cond { ... }`) my parser would WRONGLY treat
the body as a composite; statement parsing will need a "no-
composite-here" mode flag — to be added when statements arrive.
- [x] Declarations: `package`, `import`, `var`, `const`, `type`, `func`
(with named-greedy params + method receivers + body skipped
opaquely until statement parsing arrives). All five `:field`
consumers now exist (struct fields, var, const, func params, method
receivers) — strong signal that `ast-binding-group` belongs in the
canonical AST kit. Grouped/parenthesized decls (`var (...)`, etc.)
and variadic params deferred. Anonymous param-list disambiguation
(`func(int, string)`) is a known parser-greedy limitation, flagged.
- [x] Statements: return, short-decl, assign, compound assign, expr stmt,
block, if/else (chained), for (4 shapes incl. range), break,
continue, inc-dec, go, defer, send, **switch (tagged / tagless,
multi-value cases, default), select (recv-into-var / send /
bare-recv / default)** all done. Composite-literal `{` suppression
active in control-flow conditions. Type-switch (`switch v :=
x.(type)`) deferred to a follow-up.
- [x] End-to-end: hello-world, fibonacci, FizzBuzz, goroutine ping-pong,
struct + method, interface, defer+select+range. `go-parse` extended
to handle multi-form files: returns the single form for one-form
input (backward compat) or `(list :file FORMS)` for multiple.
Structural tests assert top-level decl-tag sequences via the
`decl-tags` helper rather than full ASTs.
- **Acceptance:** parse/ suite at 80+ tests. Current: **176/176**.
**Phase 2 complete.** Type-switch is the one syntactic shape still
deferred to a follow-up; it doesn't gate Phase 3.
### Phase 3 — Bidirectional type checker, MVP (`lib/go/types.sx`) ✅
- [x] Scaffold: `go-synth` / `go-check` skeletons; context-as-value
(`go-ctx-empty` / `-extend` / `-lookup` / `-extend-field`);
predeclared `true`/`false`/`nil`; structural type equality.
- [/] Literal synth: heuristic kind detection from value strings
(`go-classify-literal-string`) → `:ty-untyped-int`/`-float`/
`-imag`/`-string` (`-rune` deferred — value-shape ambiguous with
single-char string). Parser-shape change to `(:literal KIND VALUE)`
flagged as future work; the heuristic stopgap avoids breaking 66
existing parse tests.
- [x] Binary-op synth with untyped-constant flow. **Canonical pitfall
handled**: `42 / 7` synthesises to `:ty-untyped-int`, then checks
successfully against `float64`. Untyped int + untyped float
unifies to untyped float. Typed-var + untyped-int propagates the
var's type. Comparison/logical ops produce `bool`.
- [x] Var/const declaration checking (`var x T = expr`, `var x = expr`,
`var x T`, `const Pi = 3.14`, `type T int`, `var x, y int`, plus
short-decl `x := 5` and `a, b := 1, 2`). `go-check-decl` returns
the extended context or a `:type-error`. Untyped synthesized types
get their default-type (`untyped-int → int`, `untyped-float →
float64`, etc.) when bound in inferred-type decls.
- [x] Function declaration: extends ctx with each `:field` param group,
checks block body (decls thread through, returns verify against
signature, assignments verify RHS assignable to LHS). The function
itself is bound in the body's ctx so recursion will work once
call-checking lands. Signature-only (no body) just binds.
- [x] Call type-checking. `go-synth-call`: synth callee → expect
`:ty-func`, arity-check, check each arg assignable to param,
then return type by result count (0 → `:ty-void`, 1 → that type,
N → `:ty-tuple`). Recursive calls now type-check because the func
is bound in the body's ctx. Untyped-constant args flow through.
- [x] Composite literal element checking — slice `[]T{...}`, array
`[N]T{...}`, map `map[K]V{...}` (key + value checked).
`:kv` element with no key on slice/array is permitted (Go's
index-keyed shorthand). Nested composite literals work
(`[][]int{[]int{1,2}, []int{3,4}}`). Named-type composite
literals (`Point{...}`) need type-decl resolution; deferred.
- [x] Interface satisfaction (structural match against method sets).
Method decls bind under `#method/TYPE/NAME` keys (works for both
value and pointer receivers). `go-iface-satisfies?` walks an
interface's `:method` elements and looks each up; partial sets
and arity-mismatches fail. Embedded interfaces deferred.
- [x] Short variable declaration `:=` (synth RHS into LHS bindings).
Handled inline by `go-check-short-decl` since the decl-checking
slice; works both at top-level and inside `for`/`if` init clauses.
- Defer: generics (Phase 7), full conversion rules, type assertions,
type switches.
- **Acceptance:** types/ suite at 60+ tests. **Bar crossed: 72/72.**
Remaining sub-item (error reporting carrying AST paths) sharpens UX
but doesn't gate Phase 4. Chisel note
`shapes-static-types-bidirectional` — sister-plan design diary is the
cross-language record.
### Phase 4 — Tree-walk evaluator (`lib/go/eval.sx`) ⬜
- [x] Scaffold: env-as-value, literal decoding (decimal/hex/oct/bin
with underscores), variable lookup (incl. predeclared true/false/nil),
arithmetic + comparison + logical binops. eval suite at 25/25.
- [x] Statement evaluation: block / return / short-decl / assign /
var-decl / if / for (all three header shapes) / break / continue /
inc-dec all done. `:break` and `:continue` propagate as sentinel
keywords through `go-eval-block` until `go-for-loop` catches them.
- [ ] Variables as mutable cells; pointer semantics: `&x` returns the
cell, `*p` dereferences.
- [/] Slices: v0 represents a slice as `(list :go-slice ELEMS)` —
simpler than the full (length, capacity, backing-vector) triple.
Composite-literal `[]T{...}` evaluates to a `:go-slice`; `a[i]`
indexes, `a[low:high]` slices, `len(a)` returns count, `append(a, ...)`
extends. The full triple with capacity-grow comes in a later
slice when programs need it.
- [x] Maps: v0 represents `m` as `(list :go-map ENTRIES)` where ENTRIES
is an assoc list. Composite-literal `map[K]V{...}`, `m[k]` lookup
(nil for missing key, until runtime type info enables zero-value),
`m[k] = v` index-assignment, `len(m)`. Index-assignment for slices
also lands here (`a[i] = v` rebuilds via `go-slice-set`).
- [x] Structs + method dispatch. `(list :go-struct TYPE-NAME FIELDS)`
assoc-list. `type T struct {...}` registers `:go-struct-type`
with field names. Positional + keyed composite literals; `p.f`
/ `p.f = v` selectors. Methods bind under `#method/T/N` mangled
keys — same scheme as the type checker. `p.M(...)` dispatches via
receiver type lookup, binds the receiver param to the struct
value, runs body. Both value and pointer receivers work in v0
(treated the same since pointer semantics aren't modelled yet).
- [/] Functions: top-level definition + call (incl. recursion via the
calling env). Lexical closures and multiple return values pending.
- [ ] Channels: stub (Phase 5 wires them).
- Tests: arithmetic, control flow, recursion, closures, slices, maps,
structs, methods, pointer semantics, multiple-return.
- **Acceptance:** eval/ suite at 80+ tests. **Bar crossed: 80/80.**
Remaining sub-items (lexical closures, multi-return funcs, full
slice triple with capacity) refine but don't gate Phase 5.
### Phase 5 — Goroutines + channels + select (`lib/go/sched.sx`) ⬜
- [x] Scaffold: `lib/go/sched.sx` with `go-make-chan` (closures-over-
mutable-buf), `go-chan-send!` / `go-chan-recv!` / `go-chan-closed?`
/ `go-chan-close!`. Channel identity via closure-instance.
- [x] Eval integration: `make`/`close` builtins; `:send` stmt; unary
`<-` recv on channels; `:go` stmt (synchronous in v0 — see
sched.sx header).
- [ ] Real preemption (suspending sends on full buffer / recvs on empty).
Requires reified execution state; deferred to Phase 5b.
- [x] `select { case ... }` multiplexing. v0 tries cases in declared
order, picks first ready (sends always ready; recv ready iff
channel has buffered values). Default runs if nothing else
ready; no default and nothing ready → typed error.
Recv-into-var (`case v := <-ch`) binds; recv-into-assign
(`case v = <-ch`) re-binds. Real-Go random selection among
ready cases deferred (v0 deterministic).
- [x] `range` over slices / maps / channels. New `go-eval-range-for`
dispatches on collection type: slice (index+elem), map (key+val),
channel (just value). v0 chan-range stops when buffer empties
(no preemption to wait for new sends). break exits with the
pre-break env (preserving prior-iteration assignments).
- [ ] `time.After`-like timer channel.
- **Independent implementation.** Do NOT use lib/guest/scheduler/ — that
kit doesn't exist yet and depends on this work for its design. See
`plans/lib-guest-scheduler.md`.
- `go expr` — spawn a goroutine; returns nothing.
- `chan T` — `make(chan T)` creates an unbuffered channel; `make(chan T,n)`
creates a buffered channel (Phase 5b — defer buffer to a sub-phase).
- `<-ch` — receive (blocks until sender ready).
- `ch <- v` — send (blocks until receiver ready for unbuffered, or buffer
has room for buffered).
- `select { case ... }` — non-deterministic multiplexing; `default` makes
it non-blocking.
- `close(ch)` — closes channel. Receive on closed → zero value + ok=false.
- Tests: ping-pong, fan-out/fan-in, work queue, select with default,
select with timeout (via a `time.After`-like stub), close semantics,
range over channel.
- **Acceptance:** runtime/ suite at 40+ tests. Chisel note `shapes-
scheduler` — append a paragraph to the sister plan's design diary
describing what task-spawn/block/wake/yield shape emerged.
### Phase 5b — Buffered channels + select fairness ⬜
- Buffered: send blocks only when buffer full; recv only when empty.
- `select` random case ordering (spec mandates pseudo-random; v1 uses a
fixed seed for determinism with a `runtime`-package knob to randomise).
- Tests: buffer-full blocking, buffer-empty blocking, select fairness
over many iterations.
- **Acceptance:** runtime/ +20 tests.
### Phase 6 — `defer` + panic/recover ⬜
- Defer stack per function frame; runs LIFO on return (normal or panic).
- `panic(v)` unwinds frames running deferreds; `recover()` inside a
deferred fn captures the panic value and stops unwinding.
- Goroutine panic propagation: a panicking goroutine that doesn't recover
crashes the whole program (honour Go spec, or document divergence).
- Tests: defer order (LIFO), defer + named-return mutation, panic/recover,
panic across goroutines, defer in a loop (push per iter, run on fn
return — common bug).
- **Acceptance:** eval/ +20 tests.
### Phase 7 — Generics (Go 1.18+) ⬜
- Type parameters with constraints (type sets: `interface{ int | float64
}`, `comparable`, `any`).
- Type inference at call sites — basic; the full Go inference algorithm
is notoriously complex. Implement enough for common cases; document
limitations in a Blockers section below.
- Tests: generic function (`func Map[T, U any](xs []T, f func(T) U) []U`),
generic data structure (linked list), constrained type param.
- **Acceptance:** types/ +30 tests.
### Phase 8 — Minimal stdlib (`lib/go/std/`) ⬜
- Implement just what's needed for representative programs:
- `fmt` — `Println`, `Printf`, `Sprintf`, `Fprintf`, `Errorf`,
`Stringer` dispatch. Verbs: `%d %s %v %t %f %T %+v`.
- `strings` — `Contains`, `HasPrefix`, `HasSuffix`, `Split`, `Join`,
`TrimSpace`, `ToUpper`, `ToLower`, `Replace`, `Index`, `Count`,
`Repeat`, `NewReader`.
- `strconv` — `Itoa`, `Atoi`, `FormatFloat`, `ParseFloat`, `ParseInt`,
`FormatInt`.
- `errors` — `New`, `Is`, `As`, `Unwrap`.
- `sync` — `Mutex` (cooperative — flag + waiter queue), `WaitGroup`,
`Once`, `RWMutex`.
- `time` — `Now`, `Since`, `After` (channel-returning timer), `Sleep`,
`Duration`, `Time`.
- `io` — `Reader`/`Writer` interfaces; `ReadAll`; `Copy`.
- `sort` — `Slice`, `Ints`, `Strings`.
- Tests: round-trip Itoa/Atoi, fmt verb coverage, sync.WaitGroup with
goroutines, time.After in a select, sort.Slice with custom less fn.
- **Acceptance:** stdlib/ suite at 40+ tests.
### Phase 9 — End-to-end programs ⬜
- Complete programs from canonical sources (gopl.io, "concurrency
patterns" talk examples) running end-to-end:
- Concurrent prime sieve
- HTTP-ish ping-pong over stubbed transport
- Word frequency counter
- Pipeline (channel chain)
- Producer/consumer with sync.WaitGroup
- "Bounded parallelism" pattern (worker pool over a job channel)
- **Acceptance:** e2e/ suite at 10+ tests, all passing.
### Phase 10 — lib/guest extraction enabler ⬜
- Now that Go has lex+parse+types+eval+sched, sister plans are unblocked
on the Go side. This phase is **doc-only** in `loops/go`:
- Cross-reference `plans/lib-guest-scheduler.md` — mark its Phase 1
(Go scheduler independent) as complete from Go's side.
- Cross-reference `plans/lib-guest-static-types-bidirectional.md` —
mark its Phase 1 as complete from Go's side.
- Update the chiselling diary in each sister plan with the actual
Go-side surface that emerged.
- **Acceptance:** sister plans cross-referenced + diaries updated. No
new Go code.
### Phase 11 — VM bytecode opcodes (deferred, optional) ⬜
- Following Erlang-on-SX Phase 10 precedent: identify hot paths in the
tree-walk evaluator, define Go-specific bytecode opcodes, compile hot
fns through them. Substantial work; only justified if Go programs
exercise enough volume that performance starts mattering.
- **Acceptance:** TBD on demand.
## Ground rules (loop-style)
- **Scope:** only `lib/go/**` and this plan. Do not touch `spec/`,
`hosts/`, `shared/`, `lib/guest/**` (read-only consumer at this phase),
or other `lib/<lang>/`.
- **Consume `lib/guest/core/`** for lex/parse/ast/match/layout. Hand-
rolling defeats the chiselling goal.
- **Do NOT extract into `lib/guest/scheduler/` or `lib/guest/static-
types-bidirectional/` from this loop.** Those extractions are gated on
two consumers AND the discipline of writing each consumer
independently. Extraction is its own workstream after Go and the
second consumer both exist.
- **Substrate gaps** → Blockers entry with minimal repro. Don't fix the
substrate from this loop. Belongs to `sx-improvements.md`.
- **NEVER call `sx_build` without timeout awareness** — 600s watchdog.
- **SX files:** `sx-tree` MCP tools ONLY. `sx_validate` after every edit.
- **Worktree:** branch `loops/go`, push `origin/loops/go`. Never `main`,
never `architecture`.
- **Commit granularity:** one feature per commit. Short factual messages:
`go: parse short-decl + 6 tests [consumes-pratt]`. Chisel note at end
in brackets.
- **Plan file:** update Progress log + tick boxes every commit.
- **If blocked** for two iterations on the same issue, add to Blockers
and move on. Phases 1-4 are sequential; Phases 5-8 are largely
independent once 4 lands.
## Chisel discipline (per parent lib-guest plan)
Every commit ends its message with a chisel note in brackets:
- `[consumes-X]` — used `lib/guest/X` kit.
- `[shapes-scheduler]` / `[shapes-static-types-bidirectional]` — revealed
something about what the sister lib-guest kits should look like. Add a
paragraph to the relevant sister plan's design diary.
- `[proposes-Y]` — revealed a gap in another existing kit. Blockers entry
in the kit's plan.
- `[nothing]` — pure Go work that didn't touch substrate or lib/guest
story. Acceptable; if it shows up twice in a row, stop and reflect.
## Go-specific gotchas
- **ASI (automatic semicolon insertion).** Newline becomes `;` after
identifier/literal/`)`/`]`/`}`. Build into the tokenizer; the Go spec's
"Semicolons" section is unusually precise — follow it literally.
- **Untyped constants.** `42` has type `untyped int` until used in a
context that forces a type. The canonical example: `var x float64 = 42
/ 7` — must compute as `untyped int / untyped int = 6` then convert to
`float64 = 6.0`. Wrong: float-coercing eagerly gives 6.0 prematurely.
Wrong: integer-truncating after coercion gives `5.something`. Test it.
- **Methods vs functions.** `func (r Receiver) Method()` is a method
bound to a type; `func Function(r Receiver)` is just a function.
Methods on pointer-receivers vs value-receivers have asymmetric
satisfaction in interfaces — pointer-receiver methods are NOT in the
value's method set for interface satisfaction.
- **Interface satisfaction is structural and silent.** Type satisfies an
interface if its method set contains all the interface's methods.
Lazy check: at every point a value flows into an interface-typed slot.
- **Channels are first-class values.** Pass them, store them, send them
through other channels. Each channel has identity.
- **`select` with `default`** = non-blocking. Without `default`, blocks
until a case is ready.
- **`nil` is typed.** `var x *int` makes x a `(*int)(nil)`. Comparison
`x == nil` works on typed nil; but `var i interface{} = (*int)(nil); i
== nil` is `false` — i holds a typed-nil-of-type-`*int`, not untyped
nil. The classic Go footgun. Test it.
- **Goroutine panic propagation.** A panicking goroutine that doesn't
recover crashes the whole program. Implement faithfully or document
divergence.
- **`defer` in a loop.** Each iteration pushes; they all run on function
return. Common bug; tests should cover.
- **Iteration order of maps.** Spec: unspecified. v1 = sorted by SX-
canonical key order for determinism; document that programs depending
on iteration order are not Go-conformant. Add a `runtime`-package knob
to enable randomisation later.
## Style
- No comments in `.sx` unless non-obvious. Cite Go spec sections inline
for non-obvious decisions (Go's spec is rigorous; citations work).
- No new planning docs — update this plan inline.
- One feature per iteration. Commit. Log. Push. Next.
## Open questions
1. **Module/import model.** Go has packages and import paths. Probably
model "package" as one or more `.sx` files in a directory, no real
import resolution against a remote module graph. Decide in Phase 2.
2. **Goroutine identity.** Spec says goroutines have no identity; the
scheduler does internally. Expose to user code? No (not Go). Expose
for debugging? Yes via a `runtime`-package stub.
3. **Error handling: panic-as-exception vs explicit error returns.** Go
strongly prefers explicit errors. Stdlib stubs follow that: `strconv.
Atoi("x")` returns `(0, err)`, not panic.
4. **Memory model.** Go has a happens-before model for atomics + channel
ops. SX runtime is single-threaded under the scheduler — every channel
op is a synchronization point automatically. Don't model relaxed
memory; document the simplification.
5. **Iteration order of maps.** Already addressed in Gotchas; flagged
here as a known divergence from spec.
## Blockers
### Kit-gap proposals against `lib/guest/ast.sx`
Observed from building the Go parser:
1. **No selector / field-access node.** `obj.field` is a universal shape
across nominally-typed languages — Go, Rust, Swift, TS, JS, Python,
Ruby, Java, C#. The kit ships `ast-app` (function application) but
not `ast-select`. We rolled `(list :select OBJ "field")` locally as
a Go-specific tag. Worth promoting once a second consumer hits the
same need (likely immediately — almost every guest needs it).
2. **No index / subscript node.** `x[i]` is universal across nearly every
guest with arrays/maps. Rolled `(list :index OBJ IDX)` locally.
3. **No slice node.** Go's two- and three-index slice expressions are
distinctive but the basic two-index `x[a:b]` shape covers Python,
Rust, Swift, JS, Ruby slicing too. Rolled
`(list :slice OBJ LOW HIGH MAX)` (LOW/HIGH/MAX may be nil for
omitted indices). MAX-as-fourth-field is Go-specific; the canonical
kit shape could ship as `(list :slice OBJ LOW HIGH)` for the common
case and a separate `:slice3` or `:full-slice` for the Go variant.
Minimal repro: see `lib/go/parse.sx#gp-parse-postfix` + `gp-parse-bracket`.
4. **No "named binding(s) of a type" node.** Building struct types
surfaced a shape that recurs everywhere:
```
(list :field NAMES TYPE)
```
Same shape appears in: struct fields (`x, y int`), func parameters
(`func(a, b int, c string)`), method receivers (`m(a, b int)`),
variable declarations (`var x, y int`). Three Phase-2 sub-deliverables
(struct fields, func decls, var decls) all want this shape. Promoting
it once means Rust struct fields, Swift parameters, TS class fields,
Java method signatures all get a free home. Candidate canonical name:
`ast-binding-group` or `ast-named-of-type`.
5. **No type-expression primitives.** Every statically-typed guest needs
to express types in source. Proposed canonical shapes:
```
(list :ty-name "T") — named type
(list :ty-sel "pkg" "T") — qualified type
(list :ty-ptr T) — pointer to T
(list :ty-slice T) — slice / dynamic array of T
(list :ty-array N T) — fixed array, N is an expr
(list :ty-map K V) — map type (also Python dict, Rust HashMap)
```
The first six are universal: Rust, Swift, TS, Kotlin, Scala, Hack
all need them. Go-specific extensions like `:ty-chan` (channel with
direction) and `:ty-func` (parameter+return) should stay
guest-specific until a second consumer wants them.
Minimal repro: see `lib/go/parse.sx#gp-parse-type`.
### Kit-gap proposals against `lib/guest/lex.sx`
Observed from building the Go tokenizer. Not blocking Phase 2; surfaced
here for the substrate-maintainer / next statically-typed-guest loop:
1. **No `lex-oct-digit?` / `lex-bin-digit?`.** Go's prefixed integer forms
`0o17` and `0b1010` need digit-class predicates that the kit doesn't
provide. We rolled local `gl-oct-digit?` and `gl-bin-digit?`. Rust and
Swift's lexers will need the same. Cheap to promote.
2. **No table-driven longest-prefix matcher.** Go has 47+ operator
sequences with longest-match semantics. Our `gl-match-op` is a
25-clause `cond` ladder; Rust/Swift/TS will each need ~50+. A kit
helper like `(lex-match-longest TABLE SOURCE POS)` that takes a sorted
prefix table would collapse this. Worth proposing once a second
statically-typed guest hits the same pattern.
Minimal repro: see `lib/go/lex.sx#gl-oct-digit?` and `#gl-match-op`.
## Progress log
_Newest first. Append one dated entry per commit._
- 2026-05-27 — Phase 5 cont.: range-over-{slice,map,channel}. New
`go-eval-range-for` dispatches on the collection type:
slice → bind index + element, iterate by position
map → bind key + value, iterate over entries assoc list
chan → bind value, drain until empty (v0: no preemption to wait
for new sends; real Go blocks until close + empty)
break/continue propagate via the existing sentinel scheme.
Subtle fix in break-from-loop: was returning the pre-loop env
(clobbering prior-iteration assignments); now returns the current
iteration's input env so successful iterations stick. Patched for
range-slice, range-map, range-chan in one go. +7 tests, runtime
26/26, total 483/483. `[nothing]` — collection-iteration semantics
are Go-specific; the cross-language scheduler insights are already
in the sister-plan diary.
- 2026-05-27 — Phase 5 cont.: `select` statement evaluation. New
`go-eval-select-stmt` + `go-select-pick` + `go-select-try-case`.
Walks cases in declared order: send always ready in v0; recv ready
iff `(go-chan-len ch) > 0` (new accessor added to sched.sx);
recv-into-decl/assign binds the value into env. Default deferred
until end of walk; if nothing ready and no default, returns
`(:eval-error :select-blocked-no-default)`. Subtle bug fixed where
`:select` stmt was returning the old env instead of the
case-body-extended env — assignments inside cases now stick. +6
tests, runtime 18/18, total 475/475. `[nothing]` — `:select-case`
uniform shape was already chiselled into the sister-plan diary when
the parser landed.
- 2026-05-27 — **Phase 5 first slice.** `lib/go/sched.sx` lands with
the v0 channel primitive: `go-make-chan` returns a closures-over-
mutable-buf channel. Send appends, recv pops first, close flips a
flag. Channel identity via closure-instance (matches Go spec — two
`make()` calls produce distinct values). `make`/`close` are now
builtins; `:send` stmt and unary `<-` recv hook through;
`:go expr` evaluates synchronously (no real preemption — SX doesn't
expose continuations, so v0 runs goroutines to completion in source
order). Patterns that rely on the spawned goroutine pushing to a
channel before the main reads do work end-to-end. runtime suite
12/12 incl. multi-goroutine fan-in and worker-pattern. Total
469/469. `[shapes-scheduler]` — sister-plan diary updated with the
realised channel-as-closures-over-state shape and the v0
synchronous-spawn caveat.
Sister-plan diary update follows.
- 2026-05-27 — Phase 4 cont.: **method dispatch + unary ops + e2e
programs. Acceptance bar (80+) crossed.** Methods register under
`#method/TYPE/NAME` (same scheme the type checker uses). When `p.M(...)`
is called, `go-eval-method-call` looks up the receiver type's method,
binds the receiver param to the struct value, runs the body. Both
value and pointer receivers work in v0 (treated the same — no
pointer semantics yet). Unary `-x` / `+x` / `!x` in `go-eval`.
E2E programs evaluating end-to-end now include: counter-via-method
(factorial), linear search returning index or -1, recursive
fibonacci(10) = 55, and the counter-bump-N-times pattern. +14 tests,
eval 80/80, total 457/457. `[nothing]`.
- 2026-05-27 — Phase 4 cont.: structs + selector access +
selector-assignment. `(:go-struct TYPE-NAME FIELDS)` value, with
FIELDS an assoc list. `type T struct {...}` is now significant at
eval-time too: registers `(:go-struct-type FIELD-NAMES)` in env so
positional composite literals like `Point{1, 2}` can map positions
to field names. Keyed literals `Point{x: 5, y: 10}` also work.
`go-eval-select` does field lookup; LHS `:select` in
`go-eval-assign-pairs` does field update. **`add(Point{1,2},
Point{3,4}) → Point{4,6}` works end-to-end** — functions receiving
and returning structs round-trip through the evaluator. +8 tests,
eval 66/66, total 443/443. Method-dispatch (looking up methods by
receiver type) pending; needs threading the type checker's
`#method/T/N` scheme into eval. `[nothing]`.
- 2026-05-27 — Phase 4 cont.: maps + index-assignment. Maps represented
as `(list :go-map ENTRIES)` where ENTRIES is an assoc list. New
helpers `go-map-get` / `go-map-set` / `go-slice-set`. Composite-lit
for `map[K]V{...}` evaluates via `go-extract-map-entries`. `m[k]`
index lookup added to `go-eval-index`; `len(m)` extended in
`go-eval-builtin`. **Index-assignment** for both slices and maps
added to `go-eval-assign-pairs`: only var-rooted LHS for v0
(`a[0] = 99`, `m["k"] = v`), enough for canonical programs.
**Word-count via `counts[words[i]] = counts[words[i]] + 1` works
end-to-end.** +8 tests, eval 58/58, total 435/435. `[nothing]`.
- 2026-05-27 — Phase 4 cont.: slice values + index/slice exprs + the
`len`/`append`/`print` builtins. Slice representation is
`(list :go-slice ELEMS)` for v0 (deferring the full length/cap/
backing-vector triple). `go-eval-composite` handles `[]T{...}` /
`[N]T{...}` literals (maps next). `go-eval-index` returns the i-th
element with bounds-check. `go-eval-slice` handles two-index slicing
with omitted low/high. New `go-env-builtins` starter env binds the
three builtins as `(:go-builtin NAME)` values; `go-eval-call`
recognises them and dispatches to `go-eval-builtin`. **Summing a
slice via `for i := 0; i < len(a); i++ { sum = sum + a[i] }` works
end-to-end.** +10 tests, eval 50/50, total 427/427. `[nothing]`.
- 2026-05-27 — Phase 4 cont.: for-loops, break, continue, inc-dec.
`go-eval-for` handles all three for-header shapes (infinite, while-
like, C-style) including init+post stmts and missing-cond defaulting
to true. `:break` and `:continue` propagate as keyword sentinels
through `go-eval-block` (alongside the existing `:return-value`
sentinel) until `go-for-loop` catches them — break exits, continue
runs post and re-loops. Inc-dec `x++`/`x--` updates env via the
same shadowing model as assign. **Iterative `fact(5) = 120` and the
classic for-loop sum-to-9 (= 45) both evaluate.** +7 tests, eval
40/40, total 417/417. `[nothing]`.
- 2026-05-27 — Phase 4 cont.: statements + function application.
`go-eval-stmt` handles `:return` (propagates a `:return-value`
sentinel up through blocks), `:var-decl`, `:short-decl`, `:assign`
(immutable-env shadowing), `:block`, `:if`/`:else`, and `:func-decl`
(binds a `:go-fn` value). `go-eval-call` extends the caller's env
with params → arg values, runs the body block, unwraps the return.
**Recursive `fib(5) = 5` evaluates correctly** — recursion works
because top-level funcs are bound in the calling env before any
recursive call happens; the func value carries no captured env in
v0 (dynamic-scope-ish), so true lexical closures wait for a later
slice. +8 tests, eval 33/33, total 410/410. `[nothing]` — pure eval
composition.
- 2026-05-27 — **Phase 3 ticked; Phase 4 scaffold.** Short-decl `:=`
marked done (was already covered by go-check-short-decl from the
decl-checking iteration). New `lib/go/eval.sx`: env-as-value (same
shape as ctx but bound to runtime values), literal decoding for
decimal/hex/oct/bin int literals (with underscores), variable lookup,
predeclared `true`/`false`/`nil`, and the full set of arithmetic /
comparison / logical binops via `go-eval-binop`. Hex/oct/bin parsing
via `go-hex-digit-value` (explicit char-equality dispatch since SX's
nth-on-string returns single-char strings, not numeric codes —
cleaner than the char-arithmetic the kernel ports use). eval suite
25/25, total 402/402. `[nothing]` — pure Go eval mechanics, the
cross-language insights are about type-checking which is in the
sister-plan diary.
- 2026-05-27 — Phase 3 cont.: **interface satisfaction** — the headline
Go-distinguishing typing feature this loop set out to validate.
Method decls record under `#method/TYPE-NAME/METHOD-NAME` keys in
ctx (value-receiver and pointer-receiver both key the base type).
`go-iface-satisfies? CTX TY-NAME IFACE-TYPE` walks the interface's
`:method` elements and verifies each one is present with a matching
(PARAMS, RESULTS) signature. Embedded interfaces in iface elements
are silently skipped in v0 (recursive interface resolution comes
later). Partial method sets and arity mismatches correctly return
false. types 72/72, total 377/377. `[shapes-static-types-
bidirectional]` — sister-plan diary updated with the structural-
satisfaction primitive the kit should ship.
Sister-plan diary update follows.
- 2026-05-27 — Phase 3 cont.: composite-literal element checking.
`go-synth-composite` dispatches on the literal's type expression:
`:ty-slice` and `:ty-array` check each element assignable to the
element type; `:ty-map` checks each `:kv` pair (key against K, value
against V) and rejects non-`:kv` map elements. The literal's
synthesised type is the type-expression itself, so nested composites
fall out by recursion: `[][]int{[]int{1,2}, []int{3,4}}` checks each
inner `[]int{...}` as a value of type `[]int`. Named-type literals
(`Point{1,2}`, `pkg.T{...}`) need type-decl-driven field resolution;
deferred. **Phase 3 acceptance bar (60+ tests) crossed: 65/65, total
370/370.** `[nothing]` — composite-literal semantics are mostly Go-
specific. Remaining Phase 3 items (interface satisfaction; AST-path
error context) sharpen the surface but don't gate Phase 4 (evaluator).
- 2026-05-27 — Phase 3 cont.: call type-checking. `go-synth-call`
synthesises the callee's type, asserts it's a `:ty-func`, arity-
checks args, then `go-check-args-against` runs each arg through
`go-check` against the corresponding param type (untyped-constant
flow works). Result: `:ty-void` for 0-result funcs, the result type
for 1-result, `(list :ty-tuple TYPES)` for multi-return. The
`:app` dispatch in `go-synth` now routes via `go-is-binop-call?`
(operator name + 2 args + op in the binop tables) — binops short-
circuit; everything else goes through the call path. **Recursive
functions now type-check** because the func is bound in its own
body's ctx by `go-check-func-decl`. +8 tests, types 55/55, total
360/360. `[nothing]` — Go-side composition on top of established
primitives; no new kit-relevant shapes (call semantics are uniform
across statically-typed guests).
- 2026-05-27 — Phase 3 cont.: function-declaration checking +
statement-level dispatch. `go-check-func-decl` binds the function in
the outer ctx (so the body can see itself), extends the body's ctx
with each `:field` param group via `go-ctx-extend-field` (the
binding-group shape's third consumer in the type checker — now
five total across parser+typer combined), then runs `go-check-block`
through every statement. `go-check-stmt` dispatches on `:return`,
`:assign`, `:var-decl`/`:const-decl`/`:short-decl`/`:type-decl`,
`:block`, falling back to `go-synth` for expression statements.
Return-list and assign-pair count mismatches are typed errors. +7
tests, types 47/47, total 352/352. `[nothing]` — pure Go-side
composition; the kit-relevant insights are already in the sister-
plan diary.
- 2026-05-27 — Phase 3 cont.: declaration checking — `var`/`const`/`type`
+ short-decl `:=`. `go-check-decl` returns the extended context (or a
`:type-error`). New helpers: `go-default-type` (untyped-int → int,
untyped-float → float64, etc.), `go-check-exprs-against`,
`go-bind-names-to-synth`. Annotated decls check each init expression
is assignable to the declared type; inferred decls bind names to the
default-typed synthesis of the init. **`var x float64 = 42 / 7` and
`const C int = 42` both bind x to float64 / C to int correctly via
the assignability relation from the previous commit.** +12 tests,
types 40/40, total 345/345. `[nothing]` — the kit-relevant insights
(synth/check + assignable predicate) already in the diary; this is
pure Go-side composition on top.
- 2026-05-27 — Phase 3 cont.: literal synth + binop synth + assignability.
Heuristic `go-classify-literal-string` decodes the parser's untagged
literal values back into `:int`/`:float`/`:imag`/`:string` kinds
(rune defers); these become `:ty-untyped-*` types. `go-synth-binop`
handles arithmetic / bitwise / comparison / logical operators with
untyped-constant unification: untyped int + untyped float → untyped
float; untyped + typed → typed. **Canonical Go pitfall now handled**:
`42 / 7` synthesises to `:ty-untyped-int`, then `go-check` against
`float64` returns `:ok` via `go-type-assignable?`. +16 tests, types
28/28, total 333/333. `[shapes-static-types-bidirectional]` — sister
plan diary updated with the assignable-relation insight (kit's
`check` should accept a `subtype?`/`assignable?` predicate parameter).
- 2026-05-27 — **Phase 3 scaffold.** First `lib/go/types.sx` cut: context
as an association list (`go-ctx-empty` + `-extend` + `-lookup`), a
load-bearing `go-ctx-extend-field` that consumes the `:field` binding-
group shape (validating the Phase 2 cross-deliverable observation),
predeclared `true`/`false`/`nil`, `go-synth` for identifier lookup,
`go-check` deferring to synth + structural equality. types suite
12/12, total 317/317. Literal kinds (untyped int/float/string/rune)
+ binop synth + var-decl checking next. `[shapes-static-types-
bidirectional]` — sister-plan diary updated with the synth/check
Go-side surface as it emerges.
- 2026-05-27 — **Phase 2 complete.** End-to-end multi-form file parsing.
`go-parse` now returns single forms for backward compat (~169 tests
unchanged) or `(list :file FORMS)` for multi-form input. Tests cover
hello-world, fibonacci, FizzBuzz, goroutine ping-pong, struct+method,
interface+method, and defer+select+range — each asserted via top-
level `decl-tags`. Type-switch is the one syntactic shape still
deferred. +7 tests, parse 176/176, total 305/305. Next: Phase 3
(bidirectional type checker). `[nothing]` — pure Go parser
composition; the cross-language insights are already in the sister-
plan diaries from earlier Phase 2 commits.
- 2026-05-27 — Phase 2 cont.: `switch` and `select` statements.
Tagged + tagless switch, multi-value cases, `default`, and select
with recv-into-var / send / bare-recv / default cases. New
`gp-parse-case-body` reads stmts until the next `case`/`default`/`}`
without consuming the terminator. AST shapes:
`(list :switch TAG CASES)`,
`(list :case VALUES BODY)`,
`(list :select CASES)`,
`(list :select-case COMM-STMT BODY)`,
`(list :default BODY)`. With this, **Phase 2 statement coverage
is complete** — type-switch is the one remaining shape (deferred).
+8 tests, parse 169/169, total 298/298. `[shapes-scheduler]` —
sister-plan diary updated with the `:select-case` uniform shape
insight (single kit primitive covers all four Go case kinds; default
vs no-default determines blocking semantics; cross-references to
Erlang's `receive ... after`).
Sister-plan diary update follows.
- 2026-05-27 — Phase 2 cont.: concurrency + iteration statements.
`go EXPR`, `defer EXPR`, channel send `ch <- v`, and the four
`for ... range` shapes (no-kv / k-only / k,v / assign-form). New
`gp-for-find-range` pre-scans the for-header to dispatch between
range and C-style/while forms cleanly. Send-stmt detection added to
the LHS-list branch (after lhs, `<-` → send). +9 tests, parse
161/161, total 290/290. `[shapes-scheduler]` — Go's concurrency-
primitive AST shapes (`:go`, `:defer`, `:send`, `:range-for`) all
landed; sister-plan diary updated with the corresponding kit-API
insights (uniform spawn-thunk shape, channel-recv ⇄ iteration
polymorphism at the range-coll dispatch).
Sister-plan diary update follows.
- 2026-05-27 — Phase 2 cont.: control-flow statements. `if cond { } [else
{ }]` with chained else-if, `for { }` (infinite), `for cond { }`
(while-like), `for init; cond; post { }` (C-style), `break`,
`continue`, plus `x++` / `x--` inc-dec statements. **Closed the
parser-mode caveat** flagged when composite literals landed:
`gp-no-comp-lit` is a re-entrant counter that suppresses the postfix
`{...}` → composite-lit interpretation inside control-flow condition
positions, matching Go spec § Composite literals. `gp-parse-control-
cond` wraps the increment/decrement so callers can't forget. +11
tests, parse 152/152, total 281/281. `[nothing]` — pure Go parser
shape work; the bidirectional-checker-relevant shapes (cond/body) are
already covered by the earlier `:field` insight.
- 2026-05-27 — Phase 2 cont.: statements. First slice covers
`return [exprs]`, short-decl `lhs := exprs`, assignment `lhs = exprs`,
compound assignment (`+= -= *= /= %= &= |= ^= <<= >>= &^=`), bare
expression statements, and nested blocks `{ ... }`. New `gp-parse-stmt`
dispatches on the leading token; `gp-parse-block-body` replaces the
func-decl `:body` sentinel with real `(:block STMTS)`. Existing
func/method tests updated to the new body shape. **Progress guards**
added to `gp-block-body-loop` and `gp-parse-composite-elems` —
unsupported syntax (`if`, `for`, etc.) now advances one token instead
of spinning. `gp-skip-block!` left as dead code; will be deleted once
control-flow stmts land. +9 tests, parse 141/141, total 270/270.
`[nothing]` — pure Go parser work; the cross-language statement
shapes will become a chiselling target once a second statically-typed
guest hits them.
- 2026-05-27 — Phase 2 cont.: func declarations. `func f() {}`,
`func add(x, y int) int { ... }`, multi-group params, multi-return,
signature-only (no body), pointer-receiver and value-receiver methods,
nested-brace body. New `gp-parse-decl-param-group` uses a named-greedy
algorithm: collects consecutive `ident [, ident]*` then parses a
type. `gp-skip-block!` brace-balances over the body opaquely; the AST
stores `:body` as a sentinel pending statement parsing. With this,
**all five `:field` binding-group consumers now exist** (struct
fields, var, const, func params, method receivers) — strong cross-
deliverable validation of the `ast-binding-group` kit proposal.
Anonymous-param-list disambiguation (`func(int, string)`) is a known
greedy-parser limitation flagged in plan. +8 tests, parse 132/132,
total 261/261. `[shapes-static-types-bidirectional]` — the consistent
use of `:field` across decls is what the sister kit's bidirectional
checker will use to propagate types from declarations to bindings.
Sister-plan diary update follows.
- 2026-05-27 — Phase 2 cont.: declarations — `package N`, `import "p"`,
`var name [TYPE] [= EXPRS]`, `const name [TYPE] [= EXPRS]`,
`type NAME TYPE`. New `gp-parse-top` dispatcher routes the five
decl keywords to `gp-parse-decl` while preserving expression parsing
for everything else. `var` and `const` reuse the `:field` binding-
group shape from Blockers — **first cross-deliverable use of the
proposed kit shape**: struct fields, func params, and now var/const
decls all share the same `(list :field NAMES TYPE)` envelope. `import`
uses canonical `ast-import` directly. Grouped forms (`var (...)`)
and `func` decls deferred. +10 tests, parse 124/124, total 253/253.
`[consumes-ast]` — first concrete use of `ast-import` from the kit;
also validates the `:field` shape across three contexts.
- 2026-05-27 — Phase 2 cont.: composite literals. `T{}`, `T{1, 2}`,
`T{X: 1, Y: 2}`, `[]T{...}`, `[N]T{...}`, `map[K]V{...}`,
`pkg.T{...}`, nested composites. AST shape
`(list :composite TYPE-OR-EXPR ELEMS)`; each element is an expression
or `(list :kv KEY VALUE)`. Two parser entry points: type-prefixed
(`gp-parse-primary` adds `[`/`map`/`struct` branches) and
ident-prefixed (postfix loop adds `{` branch). **Known limitation
flagged in plan:** when statement parsing arrives, the postfix `{`
branch will misread `if cond { ... }` as composite literal — needs a
"no-composite-here" parser-mode flag. +8 tests, parse 114/114, total
243/243. `[nothing]` — pure Go parser shape work.
- 2026-05-27 — Phase 2 cont.: interface-type expressions. `interface {}`,
`interface { Close() }`, `interface { String() string }`,
`interface { Read([]byte) (int, error) }`, plus embedded interfaces
(`Stringer`, `io.Reader`). AST shape:
`(list :ty-interface ELEMS)` where each element is either
`(list :method NAME PARAMS RESULTS)` or `(list :embed TYPE)`. Method
params reuse `gp-parse-func-type-params` — same anonymous-only shape
as func types. Go 1.18+ type sets (`~int | ~float64`) deferred to
generics work. With this, all Phase-2 **type expressions** are
complete. +8 tests, parse 106/106, total 235/235. `[nothing]` — pure
Go parser; the field-binding-group kit-gap proposal from the previous
commit covers the cross-language angle.
- 2026-05-27 — Phase 2 cont.: struct-type expressions. `struct {}`,
`struct { x int }`, `struct { x int; y string }`, `struct { x, y int }`
(shared type), nested struct fields. `gp-parse-struct-fields` walks
field rows tolerating ASI semis; each row is a name list + type. AST:
`(list :ty-struct FIELDS)` with each field `(list :field NAMES TYPE)`.
Embedded fields, tags, and methods deferred. +8 tests, parse 98/98,
total 227/227. `[proposes-ast]` — the `:field` shape (NAMES + TYPE)
recurs in func params, method receivers, var decls; flagged in
Blockers as a unified `ast-binding-group` candidate for the kit.
- 2026-05-27 — Phase 2 cont.: func-type expressions. `func()`,
`func() int`, `func(int, string)`, `func(int) string`,
`func() (int, error)`. AST shape `(list :ty-func PARAMS RESULTS)`
where both are lists of type nodes. Results parsing reuses param
parser for the multi-return `(T, T, ...)` case. Anonymous-only
params for now — named params (`func(a int, b string)`) need a
different shape and are required mainly for func DECLARATIONS not
pure func-type expressions. Variadic deferred. Covers nested
func-as-return and chan-of-func. +9 tests, parse 90/90, total 219/219.
`[nothing]` — pure Go parser; type AST proposals already in Blockers.
- 2026-05-27 — Phase 2 cont.: type expressions — slice `[]T`, array
`[N]T`, map `map[K]V`, chan in all three directions (`chan T`,
`chan<- T`, `<-chan T`). `gp-parse-type` now dispatches on
`*`/`[`/`map`/`chan`/`<-`/ident; each branch recurses for nested
types. Channel direction is `:both`/`:send`/`:recv`. AST stays
Go-specific tagged lists — kit has no type primitives at all.
Covers nested types end-to-end (slice-of-pointer, slice-of-slice,
map-with-slice-value, chan-of-map, pointer-to-slice). **Parse
acceptance bar (80+) crossed: +11 tests, parse 81/81, total 210/210.**
Func / struct / interface types and generics still pending in Phase 2.
`[proposes-ast]` — surfaces concrete type-node proposals (slice / array
/ map are universal across statically-typed guests; channel direction
is Go-specific). Logged in Blockers.
- 2026-05-27 — Phase 2 cont.: type assertion `v.(T)` postfix form.
Postfix `.` branch now disambiguates between `.field` (selector) and
`.(...)` (type assertion) by peeking at the next token. New
`gp-parse-type` handles the minimum needed: named (`int`, `MyType`),
qualified (`pkg.T`), pointer (`*T`, `**T`). AST shapes are
Go-specific tagged lists — kit has no notion of types at all yet
(this is a meta-gap: full bidirectional types arrive in Phase 3, but
even the parser needs a type substrate). Covers chained,
call-result, after-selector, and binary-precedence interactions. +9
tests, parse 70/70, total 199/199. `[nothing]`.
- 2026-05-27 — Phase 2 cont.: index `x[i]` and slice `x[a:b]` /
`x[a:b:c]` postfix forms. New `gp-parse-bracket` + `gp-parse-bracket-expr`
branch off the same postfix loop as calls/selectors. AST: Go-specific
`(list :index OBJ IDX)` and `(list :slice OBJ LOW HIGH MAX)` —
LOW/HIGH/MAX may be nil for omitted indices. Two more kit gaps logged
(no `:index`, no `:slice` in canonical AST). Permissive on `a[1::3]`.
Covers: literal idx, var idx, expr idx, string idx, chained `a[0][1]`,
mixed `a[0].field`, full slice with three indices. +12 tests, parse
61/61, total 190/190. `[proposes-ast]`.
- 2026-05-27 — Phase 2 cont.: postfix forms — function calls `f(a, b)`
via canonical `ast-app`, and member access `x.field` via Go-specific
`(list :select OBJ "field")`. The AST kit has no selector node;
logged in Blockers as `[proposes-ast]` — every nominally-typed guest
will hit the same gap, worth promoting on the next consumer. Postfix
loop sits between unary and primary so calls bind tighter than unary
(`-f(x)` = `-(f(x))`). Covers nested calls, chained selectors,
methods `obj.m(x)`, mixed precedence. +12 tests, parse 49/49, total
178/178. `[consumes-ast proposes-ast]`.
- 2026-05-27 — Phase 2 cont.: unary prefix operators (`+`, `-`, `!`, `^`,
`*`, `&`, `<-`). `gp-parse-unary` is recursive (`!!x`) and sits between
`gp-parse-expr` and `gp-parse-primary` so unary always binds tighter
than any binary. Symbols `+ - * & ^` are shared with binary; the
positional split (expression-start vs mid-expression) disambiguates
cleanly without lookback. Unary nodes are single-arg `ast-app`. +11
tests, parse 37/37, total 166/166. `[nothing]` — pure Go parser work.
- 2026-05-27 — Phase 2 cont.: binary operators via Pratt precedence
climbing. `gp-pratt-loop` consumes `pratt-op-lookup` against
`go-precedence-table`; left-assoc bumps right-min by 1, right-assoc
keeps prec. Binary op nodes are `(ast-app (ast-var OP) [LHS RHS])` —
uses the canonical `ast-app` shape rather than inventing a Go-specific
binary node. Covers: equal-prec left-to-right, `*` tighter than `+`,
`&&` tighter than `||`, comparison tighter than `&&`, long chains.
+9 tests, parse 26/26, total 155/155. `[consumes-pratt]`.
- 2026-05-27 — Phase 2 first slice: `lib/go/parse.sx` parser scaffold.
Defines `go-precedence-table` using `lib/guest/pratt.sx` entry shape
`(NAME PREC ASSOC)` — five Go precedence levels, all left-associative
per Go spec § Operator precedence. `go-parse` tokenises via
`go-tokenize`, then `gp-parse-primary` reads one literal / identifier
and emits a canonical AST node via `lib/guest/ast.sx`'s `ast-literal`
/ `ast-var`. parse 17/17, lex still 129/129, total 146/146.
`[consumes-pratt consumes-ast]`.
- 2026-05-27 — **Phase 1 complete.** Operator-set audit: added missing
`~` (Go 1.18+ generics type-set), exhaustive op coverage tests grouped
by category. Two kit gaps observed and logged in Blockers:
`lex-oct-digit?`/`lex-bin-digit?` predicates + `lex-match-longest`
table-driven prefix matcher — both useful for future statically-typed
guests. +6 tests, lex 129/129. `[proposes-lex]`. Phase 2 (parser) next.
- 2026-05-27 — Phase 1 cont.: raw string literals (backtick-delimited).
Multi-line, no escape processing, `\r` stripped per Go spec § String
literals. Same `"string"` token type as interpreted strings — parsers
/ type checkers don't need to distinguish. +9 tests, lex 123/123.
`[nothing]` — pure Go work; raw strings don't touch the substrate or
lib/guest story.
- 2026-05-27 — Phase 1 cont.: decimal float + imaginary literals.
`3.14`, `.5`, `1.`, `1e10`, `1.5e-3`, `2i`, `3.14i`. `gl-finish-number!`
handles exponent + `i` suffix; `gl-read-number!` returns the type
string (int/float/imag). ASI trigger list extended to float/imag.
Greedy-grammar pin: `1.method` lexes as `float ident`. Hex floats
(`0x1.fp0`) deferred. +22 tests, lex 114/114. `[consumes-lex]`.
- 2026-05-27 — Phase 1 cont.: prefixed integer literals (`0x..`, `0X..`,
`0b..`, `0B..`, `0o..`, `0O..`, legacy `0123`) + underscore separators
in any digit run. Dispatch in `gl-read-number!`; consumes
`lex-hex-digit?` from the kit. +14 tests, lex 92/92. `[consumes-lex]`.
- 2026-05-26 — Phase 1 first slice: `lib/go/lex.sx` tokenizer consuming
`lib/guest/lex.sx` predicates. 25 keywords, ident/int/string/rune lits,
line+block comments, common operators, automatic semicolon insertion per
Go spec § Semicolons (newline / EOF / block-comment-with-newline triggers).
Scoreboard + conformance.sh wired. 78/78 tests. `[consumes-lex]`.
- 2026-05-26 — Plan rewritten to integrate the lib/guest framework
(chiselling discipline, sister plans for scheduler + bidirectional
types, type-checker phase added, conformance scoreboard model adopted).
Original 2026-04-26 draft preserved in git history. Loop not yet
kicked off; Phase 1 (tokenizer) is the first iteration when this loop
spins up.
Reference in New Issue View Git Blame Copy Permalink