Canonical generic functions: Map, Filter, Reduce, First end-to-end
type-check + run. Plus 20+ typer-only shape tests covering Apply,
Compose, ToMap, Swap, Box, Triple, ToSlice, Take, Send, Fill, Eq,
Values, Pair, Inspect, etc. Index synth (slice/array/map →
element type) added to typer.
v0 limitations stamped in tests: SX `/` is float (no int mod
emulation), `var r []T` indistinguishable from unbound, single-name
constraints opaque (no type-set arithmetic).
Shape locked in: "the parser recognizes shapes, the validator
recognizes roles." Same AST + different role-validators = different
guest semantics. Diary documents this as the lemma the kit should
extract — three deliverables (binding-groups, control-flow sentinels,
index synthesis) now all instantiate it.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
gp-parse-type-params consumes the optional [NAMES CONSTRAINT, ...]
clause after a func name. AST stays backward-compatible: 5-slot
func-decl when no [...] is present, 6-slot when it is.
Typer binds each type-param name as (:ty-param NAME CONSTRAINT) so
body's (:ty-name "T") references resolve. Eval is type-erasing —
ignores type info, dispatches by name + arity.
10 new tests: parse (3), types (5), eval (2). Total 527/527.
Shape: the field binding-group from the canonical kit now feeds
6 consumers (struct fields, var-decls, const-decls, params,
receivers, type-params). Confirms it as a TRUE cross-deliverable
shape — sister-plan diary documents the 5 roles binding-groups
take and why the kit should expose ONE parser + pluggable validators.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Phase 3 cont. The headline Go-distinguishing typing feature: interfaces
are satisfied *structurally and silently* — no `implements` declaration,
no nominal subtyping. Any type whose method set contains all the
interface's methods (with matching signatures) satisfies it.
Method declarations now type-check via go-check-method-decl:
* Receiver type extracted (T or *T → "T") via go-extract-recv-ty-name.
* Method signature (:ty-func PARAMS RESULTS) bound under a mangled
key "#method/RECV-NAME/METHOD-NAME" in ctx.
* Body checked with receiver + params extended into the body ctx.
go-iface-satisfies? CTX TY-NAME IFACE-TYPE walks the interface's
:method elements; for each, looks up #method/TY-NAME/METHOD-NAME and
compares (PARAMS, RESULTS) tuples. Embedded interfaces (:embed
elements) skipped in v0 — recursive interface resolution later.
Tests:
* method-decl binds under #method/Point/String
* pointer-receiver method also keys the base type
* Point with String() satisfies interface { String() string }
* empty type does NOT satisfy Stringer
* arity-mismatch method fails satisfaction
* multi-method satisfaction works
* partial method-set fails
types 72/72, total 377/377. Phase 3 sub-deliverable list is now
substantially complete; only AST-path error context remains as a UX
sharpener.
Sister-plan static-types-bidirectional diary updated with the
**constraint-satisfies? pluggable predicate** kit-API proposal —
third pluggable point after synth/check + assignable?. Go interfaces,
Haskell typeclasses, Rust traits, and TS structural subtyping all
answer "does this value-type fit this constraint-type?" with
different machinery; the kit's check uses constraint-satisfies? when
EXPECTED is itself a constraint type.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Phase 3 cont. Adds composite-literal type-checking via go-synth-composite:
[]T{...} — go-check-composite-elems with VAL-TY=T, KEY-TY=nil.
Each plain elem assignable to T; :kv element accepted
(Go's index-keyed shorthand: `[]int{0: 5, 1: 10}`)
with only the value checked.
[N]T{...} — same as slice; result :ty-array N T.
map[K]V{...} — KEY-TY=K, VAL-TY=V. Each :kv pair: key assignable
to K, value to V. Non-:kv elements in maps are
(:type-error :map-elem-missing-key).
The literal's *synthesised* type is the type expression itself, so
nested composites fall out by recursion:
[][]int{[]int{1,2}, []int{3,4}}
→ outer: go-check-composite-elems with VAL-TY=[]int
→ each inner []int{1,2} goes through go-synth-composite recursively,
yielding :ty-slice :ty-name "int" — assignable-equal to VAL-TY.
Coverage: positive cases (homogeneous slices/arrays/maps, empty
slice, nested), and three negative cases (slice element mismatch,
map key mismatch, map value mismatch). Also a decl test:
var x = []int{1, 2, 3} → binds x to :ty-slice :ty-name "int"
Named-type literals (`Point{1,2}`, `pkg.T{...}`) need type-decl-driven
field resolution; deferred. Interface satisfaction and AST-path error
context also remain — neither gates Phase 4.
**Phase 3 acceptance bar (60+) crossed: types 65/65, total 370/370.**
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Phase 3 cont. The expression-synth :app dispatch is now bifurcated:
* go-is-binop-call? — head is :var with an operator name AND 2 args
AND the operator is in one of the binop tables. Short-circuits to
go-synth-binop as before.
* Everything else routes to go-synth-call.
go-synth-call:
1. Synth the callee. Must produce a (list :ty-func PARAMS RESULTS).
Otherwise → (:type-error :not-callable TYPE).
2. Arity-check args vs params. Mismatch → (:type-error :arity-mismatch).
3. go-check-args-against: each arg assignable to corresponding param
(untyped-constant flow works — `f(42)` accepts the untyped int
into an int param).
4. Result by count:
0 results → (list :ty-void)
1 result → that result directly
N results → (list :ty-tuple TYPES) for multi-return
The recursive case lights up: go-check-func-decl binds the function
in its own body's ctx before checking. So:
func fib(n int) int { return fib(n) + fib(n) }
now type-checks because `fib` resolves inside the body, synth-call
sees its `:ty-func` and verifies the recursive call. Multi-return
functions destructure into `:ty-tuple` which short-decl will need to
consume next iteration.
types 55/55, total 360/360.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Phase 3 cont. Adds:
* go-check-func-decl — binds the function in the outer ctx (recursive
self-reference will work once call-checking lands), 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;
five total across parser+typer when counted with struct fields,
var-decls, const-decls, func params, method receivers).
* go-check-stmt — dispatches on :return / :assign / :var-decl /
:const-decl / :short-decl / :type-decl / :block; falls back to
go-synth for expression statements.
* go-check-block — threads ctx through stmts so that decls inside
the block extend the ctx for subsequent stmts.
* go-check-return-list — each return expr assignable to the
corresponding declared result type; mismatch counts are typed.
* go-check-assign / go-check-assign-pairs — RHS assignable to LHS
synthesised type, count mismatch typed.
* Helpers: go-decl-params-to-ty-list (flattens :field NAMES TYPE to
a flat list of N types), go-extend-with-params (folds extend-field
over a param-group list), go-repeat-ty.
Coverage tests:
func empty() {} → ok
func add(x, y int) int { return x + y } → ok
func bad() int { return "hi" } → typed error
func sig(x int) int → signature-only binds
func sumsq(x, y int) int { return x*x + y*y } → params visible
func two() int { var x int = 1; var y int = 2; → nested decl
return x + y }
func g() int { var x int; x = 5; return x } → assign verified
types 47/47, total 352/352.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Phase 3 cont. Adds go-check-decl which dispatches on AST shape and
returns either the extended context or a :type-error:
:var-decl (:field NAMES TYPE-or-nil) EXPRS-or-nil
:const-decl (same shape; same logic in v0 — mutability later)
:short-decl LHS-LIST EXPRS (lhs is a list of :var nodes)
:type-decl NAME TYPE (type alias)
New helpers:
go-default-type — untyped-int → int, untyped-float → float64,
etc. Used when inferring var x = EXPR.
go-check-exprs-against — every expr assignable to the declared type.
go-bind-names-to-synth — pair names with default-typed synth of
corresponding exprs; extends ctx.
The canonical Go pitfall flows through end-to-end now:
(go-check-decl ctx (go-parse "var x float64 = 42 / 7"))
→ ctx + (x → float64)
Because: 42/7 synthesises to ty-untyped-int (binop result of two
untyped operands), then go-check-exprs-against uses go-type-assignable?
to check ty-untyped-int → ty-name "float64" — :ok via the
untyped-int-to-any-numeric assignability rule. The 6 (integer) result
gets float-converted on assignment, never floated mid-computation.
types 40/40, total 345/345.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Phase 3 cont. Adds:
* go-classify-literal-string — heuristic detection of literal kind
from the value-string (parser strips lexer's kind tag; flagged for
follow-up to extend AST shape).
* go-synth-literal — :ty-untyped-int / -float / -imag / -string.
* go-synth-binop — arithmetic, bitwise, comparison, logical ops with
untyped-constant unification:
untyped-int + untyped-float → untyped-float
untyped + typed → typed
comparison ops → bool
logical ops → bool
* go-untyped? + go-type-assignable? — pluggable assignability that
swaps in where structural equality used to gate go-check. Untyped
int assignable to any numeric type; untyped float assignable to
float/complex; untyped string to string.
**Canonical Go pitfall handled correctly**: `var x float64 = 42 / 7`
parses to a binop, synth produces :ty-untyped-int (since BOTH operands
are untyped, the int division stays in the int domain), and check
against float64 returns :ok via assignability. Wrong implementations
that float-coerce eagerly would give 6.0; the right behaviour is
"compute 6 as int, then convert to float64 = 6.0".
Verified by test "binop: 42 / 7 assignable to float64 (canonical
pitfall)" and the type-only test "binop: 42 / 7 — untyped int".
Sister-plan static-types-bidirectional diary updated with the
**pluggable-assignable-predicate** kit-API proposal:
(check-with assignable? CTX EXPR EXPECTED)
Each consumer plugs in its own variance discipline (Go untyped-flow,
TS structural subtyping, Rust lifetime-aware identity) without
rewriting synth or the judgment skeleton.
types 28/28, total 333/333.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
First slice of Phase 3 (bidirectional type checker).
lib/go/types.sx defines:
* go-ctx-empty / go-ctx-extend / go-ctx-lookup — context as a value.
* go-ctx-extend-field — consumes the (:field NAMES TYPE) shape from
the parser, binding every name to the shared type. This is the
cross-deliverable validation of the :field binding-group
observation made during Phase 2 func decls: parser produces it,
type checker consumes it, same shape end-to-end.
* go-predeclared — true / false / nil baked in. Full list expanded
on demand.
* go-synth — currently handles variable lookup; literals / calls /
binops follow in subsequent iterations.
* go-check — v0 defers to synth + structural type equality. Untyped-
constant flow and assignment-compatibility relations land later.
* Type errors carry first-class tags (:unbound, :mismatch,
:unsupported-synth) so consumers and tooling can dispatch.
Conformance.sh wired with new types suite. Scoreboard cleanup: drop
the "pending" types row since the suite is now real.
types 12/12, total 317/317. Phase 3 underway.
Sister-plan static-types-bidirectional diary updated with the
synth/check shape: judgment skeleton, error tag structure, and the
proposal that `check` should accept a `subtype?` predicate parameter
so each consumer (Go untyped-constants, TS variance, Rust lifetimes)
plugs in its own variance discipline without rewriting the judgment.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
