add claude skills

2026-03-31 12:44:27 +02:00
parent 49c2e0668d
commit b444979669
13 changed files with 698 additions and 0 deletions
--- a/.claude/skills/native-monad-option/SKILL.md
+++ b/.claude/skills/native-monad-option/SKILL.md
@@ -0,0 +1,60 @@
+---
+name: native-monad-option
+description: "Option<T> API reference. ALWAYS invoke when using Some, None, Option, OptionPromise, Option.from, Option.all, Option.partition, option.map, option.flatMap, option.match(2 args), option.filter(NO errorFactory). Do not guess Option methods — consult this skill."
+---
+
+# Option<T> Usage Guide
+
+## Quick Reference
+
+| Method                  | Signature (on Some)            | Signature (on None) |
+|-------------------------|--------------------------------|---------------------|
+| `isSome()`              | `this is Some<T>`              | `this is never`     |
+| `isNone()`              | `this is never`                | `this is None`      |
+| `map(fn)`               | `(fn: (v: T) => U) => Some<U>` | `() => None`        |
+| `flatMap(fn)`           | `(fn: (v: T) => R) => R`       | `() => this`        |
+| `match(onSome, onNone)` | 2 callbacks                    | 2 callbacks         |
+| `filter(pred)`          | NO errorFactory                | `() => None`        |
+| `toNullable()`          | `T`                            | `null`              |
+| `toUndefined()`         | `T`                            | `undefined`         |
+| `toString()`            | `string`                       | `string`            |
+
+## Critical Rules
+
+1. `match()` takes exactly **2 callbacks**: `(onSome, onNone)`.
+2. `filter()` takes ONLY a predicate — NO `errorFactory` (unlike Result).
+3. Option has **NO** `mapErr()` or `flatMapErr()` — those are Result/Query only.
+4. `flatMap` constraint: `R extends Option<any>` — callback must return an Option.
+5. Type guard: after `isSome()`, access `.value`. None has no `.value`.
+6. `none()` returns a frozen singleton — do not try to construct `new None()`.
+7. `Option.from()` treats only `null | undefined` as None. `0`, `false`, `""` become `Some`.
+
+## Anti-Patterns
+
+```typescript
+// WRONG — Option.filter does NOT take errorFactory
+option.filter((v) => v > 0, () => new Error("bad"));
+
+// CORRECT — just a predicate
+option.filter((v) => v > 0);
+```
+
+```typescript
+// WRONG — mapErr does not exist on Option
+option.mapErr((e) => new Error(e));
+
+// CORRECT — Option has no error channel. Use Result if you need errors.
+```
+
+```typescript
+// WRONG — fromNullable does not exist
+Option.fromNullable(value);
+
+// CORRECT
+Option.from(value);
+```
+
+## Namespace & Async Methods
+
+Read `references/api-surface.md` for the complete Option namespace (`.from`, `.all`, `.partition`, `.compact`, `.some`,
+`.every`) and OptionPromise namespace.