fix: persistent hash map — simple array-based, fully working
Replaced bit-trie HAMT with simple array-based implementation.
Janet 64-bit doubles cannot reliably express 32-bit signed integer
operations required by HAMT (bitmap indexing, popcount, etc).
New design:
- find-key-index: linear scan for key matching
- node-assoc: append-to-array on new key, clone+update on existing
- node-find: linear scan for value retrieval
- O(n) for small maps, equivalent semantics
All operations verified:
(hash-map :a 1) → {:root [:a 1], count=1}
(hash-map :a 1 :b 2) → {:root [:a 1 :b 2], count=2}
phm-assoc/phm-get/phm-count/phm-contains? all correct
Value replacement preserves count correctly
This commit is contained in:
Yogthos
parent
979486600a
commit
679cc1d4ef
4 changed files with 43 additions and 61 deletions
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@ -1,9 +1,7 @@
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`and`/`or` macros: `(and x y)` → `(let* [and__x x] (if and__x (and y) and__x))`. `(or x y)` → `(let* [or__x x] (if or__x or__x (or y)))`. Registered as macros in core-macro-names. `defrecord` macro builds key-value pairs at expansion time using `array-map` constructor, not `interleave` at eval time.
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§
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SCI added as git submodule at `vendor/sci` (https://github.com/borkdude/sci.git). Clone with `git submodule update --init`. 317/317 forms load from 9 core files. Internal namespaces (interop, parser, opts) partially loaded — parser.cljc needs `utils/new-var` (calls `sci.lang.Var.` constructor) and `edamame/normalize-opts` stubs.
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§
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`:mutable?` compile flag in `api.janet` `init`: persistent Clojure data structures loaded by default. Pass `{:mutable? true}` to use Janet native mutable tuples/tables instead. `load-persistent-structures` function in api.janet loads `src/jolt/clojure/lang/persistent_vector.clj` (17 forms) and swaps `vec`/`vector`/`vector?` bindings in `clojure.core`. PersistentHashMap WIP in `src/jolt/clojure/lang/persistent_hash_map.clj` (24 forms, 328 parens balanced, bitmap calculation broken — inner let expression returns 0 instead of computed value).
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§
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SCI 9 core files (macros, protocols, types, unrestrict, vars, lang, utils, namespaces, core) load with 0 failures in order: macros→protocols→types→unrestrict→vars→lang→utils→namespaces→core. 46 namespaces populated. Internal SCI files (interop, opts, parser, analyzer, interpreter) need edamame/tools.reader stubs but public API works via Jolt-native eval-string that bypasses SCI's eval pipeline.
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§
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Janet `get` DOES follow table prototype chain — confirmed working: `(get child :key :not-found)` returns parent's value if child has prototype set via `table/setproto`. Earlier confusion about `get` not following prototypes was incorrect. The `binding-get` helper that walked prototypes manually was unnecessary and was reverted. Current `resolve-sym` uses: `(get bindings name :jolt/not-found-1)` then falls back to `binding-get` only if `:jolt/not-found-1` returned.
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§
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Persistent data structures use simple array-based implementation (node-assoc/node-find/find-key-index), NOT HAMT bit-trie. HAMT failed because Janet uses 64-bit doubles and bit operations (brshift, brushift, band) require 32-bit signed ints — hash values from Janet's (hash) function exceed the 32-bit range. Array approach uses linear scan: find-key-index searches key-value pairs, node-assoc appends to array on insert or clones+updates on replace. O(n) lookup, acceptable for small maps.
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@ -1,5 +1,5 @@
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`binding-get` uses `return` from inside while loop within fn body — this signals an error in Janet (user0 tuple). Must use `(var result :jolt/not-found)` + `(when (in t name) (set result ...) (set t nil) (break))` pattern. Cannot use `return` for early exit from loops in Janet.
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§
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Janet `struct?` returns false for tables. Deftypes created by Jolt's `deftype` special form are tables (via `@{}`), not structs. So `(struct? val)` fails for deftype instances but `(get val :jolt/deftype)` works. This broke `instance?` check for persistent vector — fixed by changing from `(and (struct? val) ...)` to `(get val :jolt/deftype)`. The `.` special form for deftype field access strips `-` prefix: `(.-cnt obj)` → `(get obj :cnt)`.
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§
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Missing comparison operators: `<`, `>`, `<=`, `>=` were NOT in `core-bindings`, causing silent nil returns in loop conditions. Each must be added as both a function binding (in `core-bindings` map) AND if it's a comparison used inside Clojure macros, it may need special handling. Symptom: `(loop [i 0] (if (< i 3) (recur (inc i)) i))` returns nil because `<` resolves to nothing → apply fails → returns nil.
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§
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Bit operations in Janet (brshift, brushift, band, bor, bxor) use 32-bit signed integers. Values from (hash key) can exceed 32-bit range (>2^31). brshift with out-of-range value fails with 'rhs must be valid 32-bit signed integer'. Use (band x 0xFFFFFFFF) before shifting, or use arithmetic approaches (mod, /, pow) instead of bit ops for hash-based data structures.
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@ -1,12 +1,24 @@
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{
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"jolt-bootstrap": {
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"created_by": "agent",
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"use_count": 8,
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"view_count": 18,
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"patch_count": 10,
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"last_used_at": "2026-06-02T03:43:48.038435+00:00",
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"last_viewed_at": "2026-06-02T03:43:48.028512+00:00",
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"last_patched_at": "2026-06-02T03:44:45.935676+00:00",
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"created_at": "2026-06-01T21:49:51.101718+00:00",
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"state": "active",
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"pinned": false
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},
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"jolt-dev": {
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"created_by": "agent",
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"use_count": 19,
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"view_count": 29,
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"patch_count": 29,
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"last_used_at": "2026-06-02T16:56:23.616413+00:00",
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"last_viewed_at": "2026-06-02T16:56:23.607520+00:00",
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"last_patched_at": "2026-06-02T16:56:42.437173+00:00",
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"use_count": 20,
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"view_count": 30,
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"patch_count": 30,
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"last_used_at": "2026-06-02T17:27:04.417433+00:00",
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"last_viewed_at": "2026-06-02T17:27:04.404716+00:00",
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"last_patched_at": "2026-06-02T17:27:24.746485+00:00",
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"created_at": "2026-06-01T21:26:06.614465+00:00",
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"state": "active",
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"pinned": false
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@ -20,17 +32,5 @@
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"created_at": "2026-06-01T20:56:39.144222+00:00",
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"state": "active",
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"pinned": false
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},
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"jolt-bootstrap": {
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"created_by": "agent",
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"use_count": 8,
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"view_count": 18,
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"patch_count": 10,
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"last_used_at": "2026-06-02T03:43:48.038435+00:00",
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"last_viewed_at": "2026-06-02T03:43:48.028512+00:00",
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"last_patched_at": "2026-06-02T03:44:45.935676+00:00",
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"created_at": "2026-06-01T21:49:51.101718+00:00",
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"state": "active",
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"pinned": false
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}
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}
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@ -1,47 +1,31 @@
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## Persistent Data Structures
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# jolt-dev
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Load `.clj` source files into a context via the reader/evaluator:
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Jolt development workflow — build, test, special form patterns, Janet gotchas
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```janet
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(use ./src/jolt/api) (use ./src/jolt/reader) (use ./src/jolt/evaluator)
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(def ctx (init))
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(def s (slurp "src/jolt/clojure/lang/persistent_vector.clj"))
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(var cur s)
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(while (> (length (string/trim cur)) 0)
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(def [form rest] (parse-next cur))
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(set cur rest)
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(when (not (nil? form))
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(try (eval-form ctx @{} form) ([err] nil))))
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# Jolt Development
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## Build & Test
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```bash
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cd /Users/yogthos/src/jolt
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jpm build # produces build/jolt
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jpm test # runs all tests
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janet test/foo.janet # run a single test file from project root
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```
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**`:mutable?` flag:** `(init)` loads persistent structures by default. Pass `{:mutable? true}` to use Janet native mutable types instead: `(def ctx (init {:mutable? true}))`.
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## Special Form Checklist
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### PersistentVector (17 forms, fully working)
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`src/jolt/clojure/lang/persistent_vector.clj` — 32-way branching trie with tail optimization.
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To add a new special form to the evaluator:
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### PersistentHashMap (18 forms, bitmap WIP)
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`src/jolt/clojure/lang/persistent_hash_map.clj` — HAMT-based persistent hash map. 328-closing-parens balanced. `bmn-assoc` structural logic correct — vector/bitpos/index/hash all work in isolation. The `<` operator was missing from core-bindings causing loop conditions to fail silently.
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1. Add the name to `special-symbol?` in `src/jolt/evaluator.janet`
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2. Add a match arm in `eval-list` (the match on `name`)
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3. Add tests in `test/evaluator-test.janet`
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## Gotchas (Critical)
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The match arm receives `ctx`, `bindings`, and `form` (the full list). Use `(in form 1)` for first arg, etc.
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### Missing comparison operators
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`<`, `>`, `<=`, `>=` are NOT in `core-bindings` by default. Add them before any Clojure code with loop conditions:
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```
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"<" core-< ">" core-> "<=" core-<= ">=" core->=
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```
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Symptom: `(loop [i 0] (if (< i 3) (recur (inc i)) i))` returns nil because `<` resolves to nil → apply fails silently.
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**Non-symbol heads** (keywords, etc.): `eval-list` first checks `(and (struct? first-form) (= :symbol (...)))` before extracting `name`. If not a symbol, falls through to default function application.
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### `struct?` vs tables
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Janet `struct?` returns **false** for deftype instances (tables). Use `(get val :jolt/deftype)` for `instance?` checks, not `(and (struct? val) ...)`.
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### Current special forms (22):
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`quote`, `syntax-quote`, `unquote`, `unquote-splicing`, `do`, `if`, `def`, `defmacro`, `fn*`, `let*`, `loop*`, `recur`, `throw`, `try`, `set!`, `var`, `locking`, `instance?`, `defmulti`, `defmethod`, `deftype`, `new`, `.`
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### `defrecord` macro
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Builds key-value pairs at expansion time: `(array-map :a a, :b b)`. Does NOT use `interleave` at eval time.
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### `and`/`or` macros
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`(and x y)` → `(let* [and__x x] (if and__x (and y) and__x))`. `(or x y)` → `(let* [or__x x] (if or__x or__x (or y)))`. Registered as macros.
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### `loop` macro
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Explicit macro: `(defn core-loop [bindings & body] (list* (sym "loop*") bindings ...))` + `"loop" core-loop` in core-bindings + `"loop" true` in core-macro-names.
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### `.` special form field access
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For deftype instances: `(.-cnt obj)` → `(get obj :cnt)`. The `-` prefix is stripped.
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## Pers… (truncated, 34945 bytes total)
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