<K, V>(value: unknown): value is TxHashMap<K, V>Returns true if the specified value is a TxHashMap, false otherwise.
Example (Checking TxHashMap values)
import { Effect, TxHashMap } from "effect"
const program = Effect.gen(function*() {
const txMap = yield* TxHashMap.make(["key", "value"])
console.log(TxHashMap.isTxHashMap(txMap)) // true
console.log(TxHashMap.isTxHashMap({})) // false
console.log(TxHashMap.isTxHashMap(null)) // false
console.log(TxHashMap.isTxHashMap("not a map")) // false
// Useful for type guards in runtime checks
const validateInput = (value: unknown) => {
if (TxHashMap.isTxHashMap(value)) {
// TypeScript now knows this is a TxHashMap
return Effect.succeed("Valid TxHashMap")
}
return Effect.fail("Invalid input")
}
})guards
Source effect/TxHashMap.ts:12103 lines
export const const isTxHashMap: <K, V>(
value: unknown
) => value is TxHashMap<K, V>
Returns true if the specified value is a TxHashMap, false otherwise.
Example (Checking TxHashMap values)
import { Effect, TxHashMap } from "effect"
const program = Effect.gen(function*() {
const txMap = yield* TxHashMap.make(["key", "value"])
console.log(TxHashMap.isTxHashMap(txMap)) // true
console.log(TxHashMap.isTxHashMap({})) // false
console.log(TxHashMap.isTxHashMap(null)) // false
console.log(TxHashMap.isTxHashMap("not a map")) // false
// Useful for type guards in runtime checks
const validateInput = (value: unknown) => {
if (TxHashMap.isTxHashMap(value)) {
// TypeScript now knows this is a TxHashMap
return Effect.succeed("Valid TxHashMap")
}
return Effect.fail("Invalid input")
}
})
isTxHashMap = <function (type parameter) K in <K, V>(value: unknown): value is TxHashMap<K, V>K, function (type parameter) V in <K, V>(value: unknown): value is TxHashMap<K, V>V>(value: unknownvalue: unknown): value: unknownvalue is interface TxHashMap<in out K, in out V>A TxHashMap is a transactional hash map data structure that provides atomic operations
on key-value pairs within Effect transactions. It uses an immutable HashMap internally
with TxRef for transactional semantics, ensuring all operations are performed atomically.
Example (Using transactional hash maps)
import { Effect, TxHashMap } from "effect"
const program = Effect.gen(function*() {
// Create a transactional hash map
const txMap = yield* TxHashMap.make(["user1", "Alice"], ["user2", "Bob"])
// Single operations are automatically transactional
yield* TxHashMap.set(txMap, "user3", "Charlie")
const user = yield* TxHashMap.get(txMap, "user1")
console.log(user) // Option.some("Alice")
// Multi-step atomic operations
yield* Effect.tx(
Effect.gen(function*() {
const currentUser = yield* TxHashMap.get(txMap, "user1")
if (currentUser._tag === "Some") {
yield* TxHashMap.set(txMap, "user1", currentUser.value + "_updated")
yield* TxHashMap.remove(txMap, "user2")
}
})
)
const size = yield* TxHashMap.size(txMap)
console.log(size) // 2
})
The TxHashMap namespace contains type-level utilities and helper types
for working with TxHashMap instances.
Example (Reusing extracted TxHashMap types)
import { Effect, TxHashMap } from "effect"
const program = Effect.gen(function*() {
// Create a transactional inventory map
const inventory = yield* TxHashMap.make(
["laptop", { stock: 5, price: 999 }],
["mouse", { stock: 20, price: 29 }]
)
// Extract types for reuse
type ProductId = TxHashMap.TxHashMap.Key<typeof inventory> // string
type Product = TxHashMap.TxHashMap.Value<typeof inventory> // { stock: number, price: number }
type InventoryEntry = TxHashMap.TxHashMap.Entry<typeof inventory> // [string, Product]
// Use extracted types in functions
const updateStock = (id: ProductId, newStock: number) =>
TxHashMap.modify(
inventory,
id,
(product) => ({ ...product, stock: newStock })
)
yield* updateStock("laptop", 3)
})
TxHashMap<function (type parameter) K in <K, V>(value: unknown): value is TxHashMap<K, V>K, function (type parameter) V in <K, V>(value: unknown): value is TxHashMap<K, V>V> => {
return import hasPropertyhasProperty(value: unknownvalue, const TypeId: "~effect/transactions/TxHashMap"TypeId)
}