PreparedRegExpRouter

Kind: Class

Source: src/router/reg-exp-router/prepared-router.ts

Part of: Router

PreparedRegExpRouter<T> collects route definitions and prepares regular-expression matchers for the routing layer. It separates path and wildcard handling while producing a MatcherMap<T> through buildAllMatchers().

Implements: Router

Methods

Properties

Where it refuses work

• PreparedRegExpRouter stops the work with Error when !data.

Diagram

mermaid
graph LR
  A[add method path handler] --> B{Route pattern}
  B -->|Path| C[#addPath]
  B -->|Wildcard| D[#addWildcard]
  C --> E[Prepared route data]
  D --> E
  E --> F[buildAllMatchers]
  F --> G[MatcherMap<T>]

Usage

ts
import { PreparedRegExpRouter } from './src/router/reg-exp-router/prepared-router'

type Handler = (request: Request) => Response

const router = new PreparedRegExpRouter<Handler>()

router.add('GET', '/articles/:slug', (request) => {
  return new Response(`Article request: ${request.url}`)
})

router.add('GET', '/assets/*', () => {
  return new Response('Asset request')
})

const matchers = router.buildAllMatchers()

// Pass `matchers` to the router component that resolves requests.

AI Coding Instructions

• Register routes through add(); keep #addPath() and #addWildcard() as internal preparation details.
• Preserve the generic T consistently between registered handlers and the resulting MatcherMap<T>.
• Handle wildcard paths through the existing wildcard flow rather than adding separate matcher logic at call sites.
• Build matchers after route registration and pass the resulting map to the request-matching layer.

How it works

• PreparedRegExpRouter<T> is a Router<T> implementation whose name is "PreparedRegExpRouter". Its constructor accepts a prebuilt MatcherMap<T> and a relocation map, then stores both in private fields. [src/router/reg-exp-router/prepared-router.ts:9-17]

• It expects its initialization data to describe the paths that may later be registered. buildInitParams({ paths }) builds that data by adding every path to a temporary RegExpRouter under the ALL method, exporting its compiled matchers, recording where each path’s handlers and parameter-index map belong, and clearing those handler slots before returning [matchers, relocateMap]. [src/router/reg-exp-router/prepared-router.ts:95-153]

• add(method, path, handler) registers a handler into the already prepared matcher data. If the specified method has no matcher entry, it creates one by copying the ALL matcher’s regular expression, handler lists, and static-route handler lists. [src/router/reg-exp-router/prepared-router.ts:47-59]

• For '*' and '/*', add creates [handler, {}]; for a specific method it appends that pair to every existing dynamic and static handler list for that method. For ALL, it does the same for every matcher currently present. [src/router/reg-exp-router/prepared-router.ts:19-23] [src/router/reg-exp-router/prepared-router.ts:61-70]

• For every non-wildcard path, add requires an entry in the relocation map. If none exists, it throws Error("Path <path> is not registered"). [src/router/reg-exp-router/prepared-router.ts:73-76] The relocation data determines whether the handler is appended to a static-path list or one or more dynamic handler lists, and associates the handler with the recorded ParamIndexMap. [src/router/reg-exp-router/prepared-router.ts:25-45] With method ALL, this insertion is repeated for each current matcher; otherwise it is done only for the selected method. [src/router/reg-exp-router/prepared-router.ts:77-85]

• match(method, path) is the shared regular-expression matcher. It selects the matcher for method, falling back to the ALL matcher; it first checks an exact static-path entry, then tests the path against the matcher regular expression. [src/router/reg-exp-router/matcher.ts:10-24] A non-match returns [[], emptyParam]; a dynamic match selects a handler list from the first empty capture after index 0 and returns that list with the regular-expression match array. [src/router/reg-exp-router/matcher.ts:22-29] On its first call, this function replaces the instance’s match property with the bound matching closure. [src/router/reg-exp-router/matcher.ts:10-12] [src/router/reg-exp-router/matcher.ts:31-32] PreparedRegExpRouter assigns this function as its match member. [src/router/reg-exp-router/prepared-router.ts:92]

• A match result contains handler and parameter-index-map pairs plus a parameter stash, as represented by Result<T>; static routes use an empty parameter stash. [src/router.ts:67-98] [src/router/reg-exp-router/matcher.ts:17-20] Parameter-index maps are records from parameter names to numeric capture positions. [src/router.ts:54-58]

• buildInitParams omits wildcard paths from the relocation map, because wildcard registration is handled directly by add. [src/router/reg-exp-router/prepared-router.ts:61-70] [src/router/reg-exp-router/prepared-router.ts:111-115] It also merges parameter maps and records distinct dynamic or static handler locations for each non-wildcard path. [src/router/reg-exp-router/prepared-router.ts:116-143]

• serializeInitParams converts constructor parameters to a JavaScript array-expression string. It serializes RegExp values through toString(), removes the marker quoting, adjusts doubled backslashes, and appends JSON for the relocation map. [src/router/reg-exp-router/prepared-router.ts:156-165]

Relationships

• IMPORTS → METHOD_NAME_ALL
• IMPORTS → match
• IMPORTS → emptyParam
• IMPORTS → RegExpRouter