<K, A>(self: TxHashMap<K, Option.Option<A>>): Effect.Effect<
TxHashMap<K, A>
>Removes all None values from a TxHashMap containing Option values.
Details
This function returns a new TxHashMap reference with only the Some values unwrapped. The original TxHashMap is not modified.
Example (Compacting optional values)
import { Effect, Option, TxHashMap } from "effect"
const program = Effect.gen(function*() {
// Create a map with optional user data
const userData = yield* TxHashMap.make<
string,
Option.Option<{ age: number; email?: string }>
>(
["alice", Option.some({ age: 30, email: "[email protected]" })],
["bob", Option.none()], // incomplete data
["charlie", Option.some({ age: 25 })],
["diana", Option.none()], // missing data
["eve", Option.some({ age: 28, email: "[email protected]" })]
)
// Remove all None values and unwrap Some values
const validUsers = yield* TxHashMap.compact(userData)
const size = yield* TxHashMap.size(validUsers)
console.log(size) // 3 (alice, charlie, eve)
const alice = yield* TxHashMap.get(validUsers, "alice")
console.log(alice) // Option.some({ age: 30, email: "[email protected]" })
const bob = yield* TxHashMap.get(validUsers, "bob")
console.log(bob) // Option.none() (removed from map)
// Useful for cleaning up optional data processing results
const userAges = yield* TxHashMap.map(validUsers, (user) => user.age)
const ageEntries = yield* TxHashMap.entries(userAges)
const sortedAgeEntries = ageEntries.toSorted(([left], [right]) => left.localeCompare(right))
console.log(sortedAgeEntries) // [["alice", 30], ["charlie", 25], ["eve", 28]]
})combinators
Source effect/TxHashMap.ts:20708 lines
export const const compact: <K, A>(
self: TxHashMap<K, Option.Option<A>>
) => Effect.Effect<TxHashMap<K, A>>
Removes all None values from a TxHashMap containing Option values.
Details
This function returns a new TxHashMap reference with only the Some values
unwrapped. The original TxHashMap is not modified.
Example (Compacting optional values)
import { Effect, Option, TxHashMap } from "effect"
const program = Effect.gen(function*() {
// Create a map with optional user data
const userData = yield* TxHashMap.make<
string,
Option.Option<{ age: number; email?: string }>
>(
["alice", Option.some({ age: 30, email: "[email protected]" })],
["bob", Option.none()], // incomplete data
["charlie", Option.some({ age: 25 })],
["diana", Option.none()], // missing data
["eve", Option.some({ age: 28, email: "[email protected]" })]
)
// Remove all None values and unwrap Some values
const validUsers = yield* TxHashMap.compact(userData)
const size = yield* TxHashMap.size(validUsers)
console.log(size) // 3 (alice, charlie, eve)
const alice = yield* TxHashMap.get(validUsers, "alice")
console.log(alice) // Option.some({ age: 30, email: "[email protected]" })
const bob = yield* TxHashMap.get(validUsers, "bob")
console.log(bob) // Option.none() (removed from map)
// Useful for cleaning up optional data processing results
const userAges = yield* TxHashMap.map(validUsers, (user) => user.age)
const ageEntries = yield* TxHashMap.entries(userAges)
const sortedAgeEntries = ageEntries.toSorted(([left], [right]) => left.localeCompare(right))
console.log(sortedAgeEntries) // [["alice", 30], ["charlie", 25], ["eve", 28]]
})
compact = <function (type parameter) K in <K, A>(self: TxHashMap<K, Option.Option<A>>): Effect.Effect<TxHashMap<K, A>>K, function (type parameter) A in <K, A>(self: TxHashMap<K, Option.Option<A>>): Effect.Effect<TxHashMap<K, A>>A>(
self: TxHashMap<K, Option.Option<A>>(parameter) self: {
ref: TxRef.TxRef<HashMap.HashMap<K, V>>;
toString: () => string;
toJSON: () => unknown;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
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, A>(self: TxHashMap<K, Option.Option<A>>): Effect.Effect<TxHashMap<K, A>>K, import OptionOption.type Option.Option = /*unresolved*/ anyOption<function (type parameter) A in <K, A>(self: TxHashMap<K, Option.Option<A>>): Effect.Effect<TxHashMap<K, A>>A>>
): import EffectEffect.type Effect.Effect = /*unresolved*/ anyEffect<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, A>(self: TxHashMap<K, Option.Option<A>>): Effect.Effect<TxHashMap<K, A>>K, function (type parameter) A in <K, A>(self: TxHashMap<K, Option.Option<A>>): Effect.Effect<TxHashMap<K, A>>A>> =>
import EffectEffect.gen(function*() {
const const currentMap: HashMap.HashMap<
K,
Option.Option<A>
>
const currentMap: {
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
import TxRefTxRef.const get: <A>(
self: TxRef<A>
) => Effect.Effect<A>
Reads the current value of the TxRef.
When to use
Use to read the current value of a TxRef.
Example (Reading transactional references)
import { Effect, TxRef } from "effect"
const program = Effect.gen(function*() {
const counter = yield* TxRef.make(42)
// Read the value within a transaction
const value = yield* Effect.tx(
TxRef.get(counter)
)
console.log(value) // 42
})
get(self: TxHashMap<K, Option.Option<A>>(parameter) self: {
ref: TxRef.TxRef<HashMap.HashMap<K, V>>;
toString: () => string;
toJSON: () => unknown;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
TxHashMap<in out K, in out V>.ref: TxRef.TxRef<HashMap.HashMap<K, V>>(property) TxHashMap<in out K, in out V>.ref: {
version: number;
pending: Map<unknown, () => void>;
value: A;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
const compactedMap: HashMap.HashMap<K, A>const compactedMap: {
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
import HashMapHashMap.compact(const currentMap: HashMap.HashMap<
K,
Option.Option<A>
>
const currentMap: {
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
const fromHashMap: <K, V>(
hashMap: HashMap.HashMap<K, V>
) => Effect.Effect<TxHashMap<K, V>>
Helper function to create a TxHashMap from an existing HashMap
fromHashMap(const compactedMap: HashMap.HashMap<K, A>const compactedMap: {
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
import EffectEffect.tx)