Initial import with skill sheet working

node_modules/level-transcoder/lib/encoding.d.ts

@@ -0,0 +1,158 @@
+import { BufferFormat, ViewFormat, UTF8Format } from './formats'
+
+/**
+ * Encodes {@link TIn} to {@link TFormat} and decodes
+ * {@link TFormat} to {@link TOut}.
+ */
+export abstract class Encoding<TIn, TFormat, TOut> implements IEncoding<TIn, TFormat, TOut> {
+  constructor (options: IEncoding<TIn, TFormat, TOut>)
+
+  encode: (data: TIn) => TFormat
+  decode: (data: TFormat) => TOut
+  name: string
+  format: 'buffer' | 'view' | 'utf8'
+  createViewTranscoder (): ViewFormat<TIn, TOut>
+  createBufferTranscoder (): BufferFormat<TIn, TOut>
+  createUTF8Transcoder (): UTF8Format<TIn, TOut>
+
+  /**
+   * Common name, computed from {@link name}. If this encoding is a
+   * transcoder encoding, {@link name} will be for example 'json+view'
+   * and {@link commonName} will be just 'json'. Else {@link name}
+   * will equal {@link commonName}.
+   */
+  get commonName (): string
+}
+
+export interface IEncoding<TIn, TFormat, TOut> {
+  /**
+   * Encode data.
+   */
+  encode: (data: TIn) => TFormat
+
+  /**
+   * Decode data.
+   */
+  decode: (data: TFormat) => TOut
+
+  /**
+   * Unique name.
+   */
+  name: string
+
+  /**
+   * The name of the (lower-level) encoding used by the return value of
+   * {@link encode}. One of 'buffer', 'view', 'utf8'.
+   */
+  format: 'buffer' | 'view' | 'utf8'
+
+  /**
+   * Create a new encoding that transcodes {@link TFormat} from / to a view.
+   */
+  createViewTranscoder?: (() => ViewFormat<TIn, TOut>) | undefined
+
+  /**
+   * Create a new encoding that transcodes {@link TFormat} from / to a buffer.
+   */
+  createBufferTranscoder?: (() => BufferFormat<TIn, TOut>) | undefined
+
+  /**
+   * Create a new encoding that transcodes {@link TFormat} from / to a UTF-8 string.
+   */
+  createUTF8Transcoder?: (() => UTF8Format<TIn, TOut>) | undefined
+}
+
+export interface IExternalEncoding<TIn, TFormat, TOut> {
+  /**
+   * Encode data.
+   */
+  encode: (data: TIn) => TFormat
+
+  /**
+   * Decode data.
+   */
+  decode: (data: TFormat) => TOut
+
+  /**
+   * Unique name.
+   */
+  name?: string | undefined
+
+  /**
+   * Legacy `level-codec` option that means the same as `format: 'buffer'`
+   * if true or `format: 'utf8'` if false.
+   */
+  buffer?: boolean | undefined
+
+  /**
+   * Legacy `level-codec` alias for {@link name}. Used only when the
+   * {@link name} option is undefined.
+   */
+  type?: any
+
+  /**
+   * To detect `multiformats`. If a number, then the encoding is
+   * assumed to have a {@link format} of 'view'.
+   * @see https://github.com/multiformats/js-multiformats/blob/master/src/codecs/interface.ts
+   */
+  code?: any
+}
+
+/**
+ * Names of built-in encodings.
+ */
+export type KnownEncodingName = 'utf8' | 'buffer' | 'view' | 'json' | 'hex' | 'base64'
+
+/**
+ * One of the supported encoding interfaces.
+ */
+export type MixedEncoding<TIn, TFormat, TOut> =
+  IEncoding<TIn, TFormat, TOut> |
+  IExternalEncoding<TIn, TFormat, TOut>
+
+/**
+ * Type utility to cast a built-in encoding identified by its name to an {@link Encoding}.
+ */
+export type KnownEncoding<N extends KnownEncodingName, TFormat>
+  = Encoding<KnownEncodingInput<N>, TFormat, KnownEncodingOutput<N>>
+
+/**
+ * Type utility to get the input type of a built-in encoding identified by its name.
+ */
+export type KnownEncodingInput<N extends KnownEncodingName>
+  = N extends 'utf8' ? string | Buffer | Uint8Array
+    : N extends 'buffer' ? Buffer | Uint8Array | string
+      : N extends 'view' ? Uint8Array | string
+        : N extends 'json' ? any
+          : N extends 'hex' ? Buffer | string
+            : N extends 'base64' ? Buffer | string
+              : never
+
+/**
+ * Type utility to get the output type of a built-in encoding identified by its name.
+ */
+export type KnownEncodingOutput<N extends KnownEncodingName>
+  = N extends 'utf8' ? string
+    : N extends 'buffer' ? Buffer
+      : N extends 'view' ? Uint8Array
+        : N extends 'json' ? any
+          : N extends 'hex' ? string
+            : N extends 'base64' ? string
+              : never
+
+/**
+ * Type utility to use a {@link MixedEncoding} with an untyped format.
+ */
+export type PartialEncoding<TIn, TOut = TIn> = MixedEncoding<TIn, any, TOut>
+
+/**
+ * Type utility to use a {@link MixedEncoding} with an untyped format and output.
+ * For when only the encoding side is needed.
+ */
+export type PartialEncoder<TIn> = MixedEncoding<TIn, any, any>
+
+/**
+ * Type utility to use a {@link MixedEncoding} with an untyped input and format.
+ * For when only the decoding side is needed.
+ */
+export type PartialDecoder<TOut> = MixedEncoding<any, any, TOut>