parse-function now consumes optional 'when GUARD-EXPR' before -> and
emits (:case-when PAT GUARD BODY) — same handling as match clauses.
function-style sign extraction now works:
(function | n when n > 0 -> 1 | n when n < 0 -> -1 | _ -> 0)
Group anagrams by canonical (sorted-chars) key using Hashtbl +
List.sort. Demonstrates char-by-char traversal via String.get + for-loop +
ref accumulator + Hashtbl as a multi-valued counter.
Untyped lambda calculus interpreter inside OCaml-on-SX:
type term = Var | Abs of string * term | App | Num of int
type value = VNum of int | VClos of string * term * env
let rec eval env t = match t with ...
(\x.\y.x) 7 99 = 7. The substrate handles two ADTs, recursive eval,
closure-based env, and pattern matching all written as a single
self-contained OCaml program — strong validation.
ocaml-type-of-program now handles :def-mut (sequential generalize) and
:def-rec-mut (pre-bind tvs, infer rhs, unify, generalize all, infer
body — same algorithm as the inline let-rec-mut version).
Mutual top-level recursion now type-checks:
let rec even n = ... and odd n = ...;; even 10 : Bool
let rec map f xs = ... and length lst = ...;; map :
('a -> 'b) -> 'a list -> 'b list
Memoized fibonacci using Hashtbl.find_opt + Hashtbl.add.
fib(25) = 75025. Demonstrates mutable Hashtbl through the OCaml
stdlib API in real recursive code.
4-queens via recursive backtracking + List.fold_left. Returns 2 (the
two solutions of 4-queens). Per-program timeout in run.sh bumped to
240s — the tree-walking interpreter is slow on heavy recursion but
correct.
The substrate handles full backtracking + safe-check recursion +
list-driven candidate enumeration end-to-end.
Counter-style record with two mutable fields. Validates the new
r.f <- v field mutation end-to-end through type decl + record literal
+ field access + field assignment + sequence operator.
type counter = { mutable count : int; mutable last : int }
let bump c = c.count <- c.count + 1 ; c.last <- c.count
After 5 bumps: count=5, last=5, sum=10.
<- added to op-table at level 1 (same as :=). Eval short-circuits on
<- to mutate the lhs's field via host SX dict-set!. The lhs must be a
:field expression; otherwise raises.
Tested:
let r = { x = 1; y = 2 } in r.x <- 5; r.x (5)
let r = { x = 0 } in for i = 1 to 5 do r.x <- r.x + i done; r.x (15)
let r = { name = ...; age = 30 } in r.name <- "Alice"; r.name
The 'mutable' keyword in record type decls is parsed-and-discarded;
runtime semantics: every field is mutable. Phase 2 closes this gap
without changing the dict-based record representation.
type r = { x : int; mutable y : string } parses to
(:type-def-record NAME PARAMS FIELDS) with FIELDS each (NAME) or
(:mutable NAME). Parser dispatches on { after = to parse field list.
Field-type sources are skipped (HM registration TBD). Runtime no-op
since records already work as dynamic dicts.
bash lib/ocaml/conformance.sh now runs lib/ocaml/baseline/run.sh and
aggregates pass/fail counts under a 'baseline' suite. Full-suite
scoreboard now reports both unit-test results and end-to-end OCaml
program runs in a single artifact.
Polymorphic binary search tree with insert + in-order traversal.
Exercises parametric ADT (type 'a tree = Leaf | Node of 'a * 'a tree
* 'a tree), recursive match, List.append, List.fold_left.
Classic fizzbuzz using ref-cell accumulator, for-loop, mod, if/elseif
chain, String.concat, Int.to_string. Output verified via String.length
of the comma-joined result for n=15: 57.
print_string / print_endline / print_int / print_newline now route to
SX display primitive (not the non-existent print/println). print_endline
appends '\n'.
let _ = expr ;; at top level confirmed working via the
wildcard-param parser.
ocaml-infer-let-mut: each rhs inferred in parent env, generalized
sequentially before adding to body env.
ocaml-infer-let-rec-mut: pre-bind all names with fresh tvs; infer
each rhs against the joint env, unify each with its tv, then
generalize all and infer body.
Mutual recursion now type-checks:
let rec even n = if n = 0 then true else odd (n - 1)
and odd n = if n = 0 then false else even (n - 1)
in even : Int -> Bool
Option: join, to_result, some, none.
Result: value, iter, fold.
Bytes: length, get, of_string, to_string, concat, sub — thin alias of
String (SX has no separate immutable byte type).
Ordering fix: Bytes module placed after String so its closures capture
String in scope. Earlier draft put Bytes before String which made
String.* lookups fail with 'not a record/module' (treated as nullary
ctor).
Recursive-descent calculator parses '(1 + 2) * 3 + 4' = 13. Two parser
bugs fixed:
1. parse-let now handles inline 'let rec a () = ... and b () = ... in
body' via new (:let-rec-mut BINDINGS BODY) and (:let-mut BINDINGS
BODY) AST shapes; eval handles both.
2. has-matching-in? lookahead no longer stops at 'and' — 'and' is
internal to let-rec, not a decl boundary. Without this fix, the
inner 'let rec a () = ... and b () = ...' inside a let-decl rhs
would have been treated as the start of a new top-level decl.
Baseline exercises mutually-recursive functions, while-loops, ref-cell
imperative parsing, and ADT-based AST construction.
Parser fix: at-app-start? and parse-app's loop recognise prefix !
as a deref of the next app arg. So 'List.rev !b' parses as
'(:app List.rev (:deref b))' instead of stalling at !.
Buffer module backed by a ref holding string list:
create _ = ref []
add_string b s = b := s :: !b
contents b = String.concat "" (List.rev !b)
add_char/length/clear/reset
Uses Map.Make(StrOrd) + List.fold_left to count word frequencies;
exercises the full functor pipeline with a real-world idiom:
let inc_count m word =
match StrMap.find_opt word m with
| None -> StrMap.add word 1 m
| Some n -> StrMap.add word (n + 1) m
let count words = List.fold_left inc_count StrMap.empty words
10/10 baseline programs pass.
Was unconditionally throwing "Function constructor not supported".
Now js-function-ctor joins param strings with commas, wraps the
body in (function(<params>){<body>}), and runs it through js-eval.
Now Function('a', 'b', 'return a + b')(3,4) === 7.
built-ins/Function: 0/14 → 4/14. conformance.sh: 148/148.
Both written in OCaml inside lib/ocaml/runtime.sx:
module Map = struct module Make (Ord) = struct
let empty = []
let add k v m = ... (* sorted insert via Ord.compare *)
let find_opt / find / mem / remove / bindings / cardinal
end end
module Set = struct module Make (Ord) = struct
let empty = []
let mem / add / remove / elements / cardinal
end end
Sorted association list / sorted list backing — linear ops but
correct. Strong substrate-validation: Map.Make is a non-trivial
functor implemented entirely on top of the OCaml-on-SX evaluator.
os_type="SX", word_size=64, max_array_length, max_string_length,
executable_name="ocaml-on-sx", big_endian=false, unix=true,
win32=false, cygwin=false. Constants-only for now — argv/getenv_opt/
command would need host platform integration.
ocaml-hm-parse-type-src recognises primitive type names (int/bool/
string/float/unit), tyvars 'a, and simple parametric T list / T option.
Replaces the previous int-by-default placeholder in
ocaml-hm-register-type-def!.
So 'type tag = TStr of string | TInt of int' correctly registers
TStr : string -> tag and TInt : int -> tag. Pattern-match on tag
gives proper field types in the body. Multi-arg / function types
still fall back to a fresh tv.
Three related fixes:
1. Every JS function body binds arguments to (cons p1 ... __extra_args__),
so arguments[k] and arguments.length work as expected.
2. Array.from(iter, mapFn) invokes mapFn through js-call-with-this
with the index as second arg (was (map-fn x), missing index and
inheriting outer this).
3. thisArg defaults to js-global-this when omitted (per non-strict ES).
conformance.sh: 148/148.
Parser: when | follows a pattern inside parens, build (:por ALT1 ALT2
...). Eval: try alternatives, succeed on first match. Top-level |
remains the clause separator — parens-only avoids ambiguity without
lookahead.
Examples now work:
match n with | (1 | 2 | 3) -> 100 | _ -> 0
match c with | (Red | Green) -> 1 | Blue -> 2
module type S = sig DECLS end is parsed-and-discarded — sig..end
balanced skipping in parse-decl-module-type. AST (:module-type-def
NAME). Runtime no-op (signatures are type-level only).
Allows real OCaml programs with module type decls to parse and run
without stripping the sig blocks.
Parser: { f1 = pat; f2 = pat; ... } in pattern position emits
(:precord (FIELDNAME PAT)...). Mixed with the existing { in
expression position via the at-pattern-atom? whitelist.
Eval: :precord matches against a dict; required fields must be present
and each pat must match the field's value. Can mix literal+var:
'match { x = 1; y = y } with | { x = 1; y = y } -> y' matches only
when x is 1.
A tiny arithmetic-expression evaluator using:
type expr = Lit of int | Add of expr*expr | Mul of expr*expr | Neg of expr
let rec eval e = match e with | Lit n -> n | Add (a,b) -> ...
Exercises type-decl + multi-arg ctor + recursive match end-to-end.
Per-program timeout in run.sh bumped to 120s.
Was always emitting comma-joined via js-list-join, so user
mutations of Array.prototype.toString had no effect on String(arr)
/ "" + arr. Now look up the override via js-dict-get-walk and call
it on the list as this; fall back to (js-list-join v ",") when the
override doesn't return a string.
String fail count: 11 → 9. conformance.sh: 148/148.
The previous fd-fire-store fired every constraint exactly once. That
left the propagation incomplete in chains like
fd-plus c4 1 a; fd-neq c3 a
where, on the round c4 binds, fd-plus binds a, but fd-neq c3 a was
already past — so the conflict went undetected.
New: fd-store-signature is sum-of-domain-sizes + count-of-bindings.
fd-fire-store calls fd-fire-list and recurses while the signature
strictly decreases. Reaches a fixed point or fails.
This makes N-queens via FD tractable:
4-queens -> ((2 4 1 3) (3 1 4 2)) — exactly the two solutions.
5-queens -> 10 solutions (the canonical count), in seconds.
Phase 6 marked complete in the plan: domains, fd-in, fd-eq, fd-neq,
fd-lt, fd-lte, fd-plus, fd-times, fd-distinct, fd-label, all wired
through the constraint-reactivation loop.
Two new tests, 626/626 cumulative.
Real bug: the worklist used (set! queue (rest queue)) to pop the
head, which left queue bound to a fresh empty list as soon as the
last item was popped. Subsequent (append! queue ...) was a no-op
on the empty list — so when the head's rewrite generated new
(rel, adn) pairs to enqueue, they vanished. Multi-relation
programs (e.g. shortest -> path -> edge, or chained derived
relations) only had their head's rules rewritten; downstream
rules silently dropped.
Fix: use an index-based loop (idx 0 → len queue), with append!
adding to the same list. Items added after the current pointer
are picked up in subsequent iterations.
2 new regression tests:
- 4-level chain (a → r1 → r2 → r3 → r4) under magic returns 2
- shortest-path demo via magic equals dl-query (1 result)
Ground-cases propagator parallel to fd-plus. Division back-direction
checks (mod z x) = 0 before recovering a divisor. Edge cases:
multiplying by zero binds the product to zero; with z=0 and one
factor zero, the other factor is unconstrained.
7 tests including divisor enumeration, square-of-each, divisibility
rejection. 624/624 cumulative.
Ground-cases propagator: when at least two of {x, y, z} walk to
ground numbers, the third is derived (or checked, if also ground).
Three vars with domains: deferred — no bounds-consistency in this
iteration.
Includes a small fd-bind-or-narrow helper that handles the common
"bind a var to a target int, respecting any existing domain"
pattern shared across propagators.
7 new tests: ground/ground/ground, recover x, recover y, impossible
case, domain-check rejection, x+y=5 enumeration, large numbers.
617/617 cumulative.
(fd-distinct (list a b c ...)) imposes pairwise distinctness via O(n²)
fd-neq constraints. Each fd-neq propagates independently when any pair
becomes ground or has a domain-removable value.
Tests: empty/singleton trivially succeed; pair-distinct/equal cover
correctness; 3-perms-of-3 = 6 and 4-perms-of-4 = 24 confirm full
permutation enumeration; pigeonhole 4-of-3 fails.
7 new tests, 610/610 cumulative.
Three more constraint goals built on the same propagator-store
machinery as fd-neq:
fd-lt: x < y. Ground/ground compares; var/num filters domain;
var/var narrows x's domain to (< y-max) and y's to (> x-min).
fd-lte: ≤ variant.
fd-eq: x = y. Ground/ground checks. Var/num: requires num to be in
var's domain (or var unconstrained) before binding. Var/var: intersect
domains, narrow both, then unify the vars.
10 new tests: narrowing against ground, ordered-pair generation,
chained x<y<z determinism, domain-sharing, out-of-domain rejection.
603/603 cumulative (100/100 across the four CLP(FD) test files).
