<const L extends ReadonlyArray<SchemaAST.LiteralValue>>(
literals: L,
name?: string
): Config<L[number]>Creates a config that only accepts one of the specified literal values.
When to use
Use to restrict a config to a fixed set of allowed literal values.
Details
Shortcut for Config.schema(Schema.Literals(literals), name).
Example (Restricting to a set of literals)
import { Config } from "effect"
const env = Config.literals(["development", "production"], "ENV")export function function literals<
L extends ReadonlyArray<SchemaAST.LiteralValue>
>(literals: L, name?: string): Config<L[number]>
Creates a config that only accepts one of the specified literal values.
When to use
Use to restrict a config to a fixed set of allowed literal values.
Details
Shortcut for Config.schema(Schema.Literals(literals), name).
Example (Restricting to a set of literals)
import { Config } from "effect"
const env = Config.literals(["development", "production"], "ENV")
literals<const function (type parameter) L in literals<const L extends ReadonlyArray<SchemaAST.LiteralValue>>(literals: L, name?: string): Config<L[number]>L extends interface ReadonlyArray<T>ReadonlyArray<import SchemaASTSchemaAST.type LiteralValue =
| string
| number
| bigint
| boolean
The set of primitive types that can appear as a
Literal
value.
LiteralValue>>(literals: const L extends ReadonlyArray<SchemaAST.LiteralValue>literals: function (type parameter) L in literals<const L extends ReadonlyArray<SchemaAST.LiteralValue>>(literals: L, name?: string): Config<L[number]>L, name: string | undefinedname?: string) {
return function schema<T>(
codec: Schema.ConstraintCodec<T, unknown>,
path?: string | ConfigProvider.Path
): Config<T>
Creates a Config<T> from a Schema.Codec.
When to use
Use when you need to read structured or schema-validated configuration.
Details
The optional path sets the local path segment(s) for the config lookup.
It is appended to the logical path prefix accumulated from outer
nested
calls. Pass a single string for a flat key or an array for
nested paths.
Convenience constructors such as string, number, and boolean delegate
to this API.
The codec is used to decode the raw StringTree produced by the provider
into T. Schema validation errors are wrapped in ConfigError.
Example (Reading a structured config)
import { Config, ConfigProvider, Effect, Schema } from "effect"
const DbConfig = Config.schema(
Schema.Struct({
host: Schema.String,
port: Schema.Int
}),
"db"
)
const provider = ConfigProvider.fromUnknown({
db: { host: "localhost", port: 5432 }
})
// Effect.runSync(DbConfig.parse(provider))
// { host: "localhost", port: 5432 }
schema(import SchemaSchema.function Literals<
L extends ReadonlyArray<SchemaAST.LiteralValue>
>(literals: L): Literals<L>
Creates a union schema from an array of literal values.
Example (Defining status codes)
import { Schema } from "effect"
const schema = Schema.Literals(["active", "inactive", "pending"])
// accepts "active", "inactive", or "pending"
Literals(literals: const L extends ReadonlyArray<SchemaAST.LiteralValue>literals), name: string | undefinedname)
}