function splitNotation
splitNotation(notation: string): Notation

Splits an IP notation string into its address, zone ID and prefix slots.

One pass over the string records where % and / are, then slices. Nothing about IP is checked here; the parsers that call this do that on the slices. Exactly five shapes are rejected, all TypeError:

  • % more than once: fe80::1%eth0%1
  • / more than once: 10.0.0.0/8/8
  • % after /: 10.0.0.0/8%eth0 (RFC 4007 section 11.7 puts the zone first)
  • an empty address: %eth0, /64
  • an empty zone ID or prefix: fe80::1%, 10.0.0.0/

Because no slot may contain % or /, both positions are unique, and the zone slice ends at the / rather than running to the end of the string. fe80::1%eth0/64 is therefore the zone eth0 with the prefix 64; there is no greedy reading to get wrong.

Examples

An address alone

import { assertEquals } from "@std/assert";
import { splitNotation } from "@hertzg/ip/notation";

assertEquals(splitNotation("192.168.1.1"), { address: "192.168.1.1" });
assertEquals(splitNotation("fe80::1"), { address: "fe80::1" });

The zone slice stops at the slash

import { assertEquals } from "@std/assert";
import { splitNotation } from "@hertzg/ip/notation";

assertEquals(splitNotation("fe80::1%eth0/64"), {
  address: "fe80::1",
  zoneId: "eth0",
  prefix: "64",
});
assertEquals(splitNotation("fe80::1%eth0.100"), {
  address: "fe80::1",
  zoneId: "eth0.100",
});

The five rejected shapes

import { assertThrows } from "@std/assert";
import { splitNotation } from "@hertzg/ip/notation";

assertThrows(() => splitNotation("fe80::1%eth0%1"), TypeError);
assertThrows(() => splitNotation("10.0.0.0/8/8"), TypeError);
assertThrows(() => splitNotation("10.0.0.0/8%eth0"), TypeError);
assertThrows(() => splitNotation("%eth0"), TypeError);
assertThrows(() => splitNotation("fe80::1%"), TypeError);
assertThrows(() => splitNotation("10.0.0.0/"), TypeError);

Parameters

notation: string

The notation string

Return Type

The three slots as slices; zoneId and prefix are present only when the string has them

Throws

TypeError

On any of the five shapes above

Usage

import { splitNotation } from "notation.ts";