053ed4f790
- types.janet: type-registry, register-protocol-method, find-protocol-method, type-satisfies? - core.janet: rewritten protocol macros (defprotocol, extend-type, extend-protocol, reify) Protocol value stores :jolt/type :jolt/protocol with :methods map Method dispatch fns use fn* [this & rest-args] → protocol-dispatch special form - evaluator.janet: protocol-dispatch, register-method, make-reified special forms satisfies? special form with type registry lookup special-symbol? entries for all 3 protocol ops + satisfies? - 4 test sections (35-38): defprotocol, extend-type, extend-protocol, satisfies? extend-type: basic dispatch works (42 constant), .-field accessor needs further debug satisfies?: fully functional with type registry - 315 ok, 2 fail (pre-existing, unchanged)
45 lines
1.5 KiB
Markdown
45 lines
1.5 KiB
Markdown
---
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name: jolt-gotchas
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description: Common pitfalls and workarounds discovered during Jolt implementation
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---
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# jolt-gotchas
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Recurring pitfalls and their fixes discovered across all implementation phases.
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## PHM/Set Metadata Key Leakage
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PHM and set internal keys (`:jolt/deftype`, `:cnt`, `:buckets`, `:_meta`, `:jolt/type`, `:phm`) leak into `pairs`/`keys` iteration. Must filter in merge, merge-with, keys, vals, and print-collection.
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```janet
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(when (and (not= k :jolt/deftype) (not= k :cnt)
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(not= k :buckets) (not= k :_meta)
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(not= k :jolt/type) (not= k :phm)) ...)
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```
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## Keywords with `#` Are Invalid Janet Literals
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`:#inst`, `:#uuid` cause parse errors. Use dynamic table construction:
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```janet
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(let [dr @{}] (put dr (keyword "#inst") fn) dr)
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```
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## Janet `break` Only Works in Loops
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Does NOT work inside `let`. Use `(var found nil)` + `(set found val) (break)` pattern.
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## Bare Tuples in `eval` Are Function Calls
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`(eval [1 2 3])` calls `1` as function. Use `['tuple 1 2 3]` in data-structure emitter.
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## Janet `case` for Multi-Arity
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Janet lacks Clojure-style multi-arity defn. Use `(defn f [& args] (case (length args) 1 ... 2 ...))`.
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## core-renames + core-fn-values Must Stay in Sync
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Both tables must be updated together when adding core fns. Missing entries = silent nil returns. `"-"` is `core-sub` NOT `core--`.
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## `set!` Field Mutation Reader Quirk
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`(set! (.-x obj) val)` parses as array with `.-x` symbol head — not as standalone `.-x` symbol. Check for this case before the `(. obj -field)` shorthand.
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