@ndn/tlv/lib/struct-field_browser.js

NDNts: TLV

import { toHex, toUtf8 } from "@ndn/util";
import { Decoder } from "./decoder_browser.js";
import { Encoder } from "./encoder_browser.js";
import { NNI } from "./nni_browser.js";
export var StructFieldType;
(function (StructFieldType) {
    /**
     * Turn a TLV class into a field type, where the TLV directly appears as the field.
     *
     * @example
     * Given this structure:
     * ```abnf
     * Outer = OUTER-TYPE TLV-LENGTH Inner
     * Inner = INNER-TYPE TLV-LENGTH INNER-VALUE
     * ```
     *
     * You can define the `Outer` builder:
     * ```ts
     * const buildOuter = new StructBuilder("Outer", TT.Outer)
     *   .add(TT.Inner, "inner", StructFieldType.wrap(Inner));
     * ```
     *
     * `Inner` type must encode itself as a TLV, and its TLV-TYPE must equal field TLV-TYPE.
     */
    function wrap(F, overrides = {}) {
        return {
            newValue: () => new F(),
            encode: (value) => {
                const d = new Decoder(Encoder.encode(value));
                return d.read().value;
            },
            decode: ({ decoder }) => decoder.decode(F),
            asString: (value) => value.toString(),
            ...overrides,
        };
    }
    StructFieldType.wrap = wrap;
    /**
     * Turn a TLV class into a field type, where the TLV is nested inside the field.
     *
     * @example
     * Given this structure:
     * ```abnf
     * Outer = OUTER-TYPE TLV-LENGTH Middle
     * Middle = MIDDLE-TYPE TLV-LENGTH Inner
     * Inner = INNER-TYPE TLV-LENGTH INNER-VALUE
     * ```
     *
     * You can define the `Outer` builder:
     * ```ts
     * const buildOuter = new StructBuilder("Outer", TT.Outer)
     *   .add(TT.Middle, "inner", StructFieldType.nest(Inner));
     * ```
     *
     * `Inner` type does not have to encode itself as a TLV. Its encoding result appears as
     * the TLV-VALUE of the "middle" field TLV.
     */
    function nest(F, overrides = {}) {
        return {
            newValue: () => new F(),
            encode: (value) => value,
            decode: ({ vd }) => vd.decode(F),
            asString: (value) => value.toString(),
            ...overrides,
        };
    }
    StructFieldType.nest = nest;
})(StructFieldType || (StructFieldType = {}));
export const StructFieldBool = {
    newValue: () => false,
    encode: (value) => value ? new Uint8Array(0) : Encoder.OmitEmpty,
    decode: () => true,
};
/**
 * StructBuilder field type of non-negative integer.
 *
 * @remarks
 * The field is defined as number.
 * If the field is required, it is initialized as zero.
 */
export const StructFieldNNI = {
    newValue: () => 0,
    encode: NNI,
    decode: ({ nni }) => nni,
};
/**
 * StructBuilder field type of non-negative integer.
 *
 * @remarks
 * The field is defined as bigint.
 * If the field is required, it is initialized as zero.
 */
export const StructFieldNNIBig = {
    newValue: () => 0n,
    encode: NNI,
    decode: ({ nniBig }) => nniBig,
};
/**
 * Declare a StructBuilder field type of non-negative integer from an enum.
 * @param Enum - A flat (not OR'ed flags) enum type.
 *
 * @remarks
 * The field is defined as a flat enum type.
 * If the field is required, it is initialized as zero.
 */
export function StructFieldEnum(Enum) {
    return {
        ...StructFieldNNI,
        asString: (value) => `${value}(${Enum[value] ?? "unknown"})`,
    };
}
/**
 * StructBuilder field type of UTF-8 text.
 *
 * @remarks
 * The field is defined as string.
 * If the field is required, it is initialized as an empty string.
 */
export const StructFieldText = {
    newValue: () => "",
    encode: toUtf8,
    decode: ({ text }) => text,
    asString: (value) => JSON.stringify(value),
};
/**
 * StructBuilder field type of raw bytes.
 *
 * @remarks
 * The field is defined as Uint8Array.
 * If the field is required, it is initialized as an empty Uint8Array.
 */
export const StructFieldBytes = {
    newValue: () => new Uint8Array(),
    encode: (value) => value,
    decode: ({ value }) => value,
    asString: (value) => toHex(value),
};