PuduLangHttpClient.Handler

type: module path: "@root/src/PuduLangHttpClient/Handler.pudu" fidelity: Active grammar: "[[grammar/pudu]]" depth_score: 0.6 depth_status: MODERATE tags: [module, backbone] aliases: [PuduLangHttpClient.Handler]

Purpose

Delegating handlers and their composition around a primary handler.

Interface

Signatures

export type Send = fn(Request.Request, Cancel.Token) -> HttpClient.Outcome[Response.Response]

export type Handler = fn(Request.Request, Cancel.Token, Send) -> HttpClient.Outcome[Response.Response]

export fn compose(handlers: &Array[Handler], primary: Send) -> Send

export fn around(handler: Handler, inner: Send) -> Send

export fn before(step: fn(Request.Request) -> Request.Request) -> Handler

export fn after(step: fn(Response.Response) -> Response.Response) -> Handler

export fn passThrough() -> Handler

Linkage

• Requires: [[src/PuduLangHttpClient]], [[src/PuduLangHttpClient/Request]], [[src/PuduLangHttpClient/Response]], the standard library.
• Consumed by: [[src/PuduLangHttpClient/Client]], [[src/PuduLangHttpClient/Events/Bus]], [[src/PuduLangHttpClient/Factory]], [[src/PuduLangHttpClient/Factory/Builder]], [[src/PuduLangHttpClient/Factory/Entry]], [[src/PuduLangHttpClient/Handlers/Authorization]], [[src/PuduLangHttpClient/Handlers/Logging]], [[src/PuduLangHttpClient/Handlers/Metrics]], [[src/PuduLangHttpClient/Handlers/Propagation]], [[src/PuduLangHttpClient/Handlers/Resilience]], [[src/PuduLangHttpClient/Stub]], [[src/PuduLangHttpClient/Transport]].

Algorithm

1. Send is the primary handler's shape; Handler sees the request, may call the rest, and sees the outcome.
2. compose wraps handlers from the innermost out, so the first is outermost.

Negative Logic (Prohibited Paths)

• A handler never reaches the transport except through the Send it is given.

Edge Cases

• No handlers leave the primary handler alone.

Depth

DEPTH 0.6 (MODERATE). Tested by the suite mirroring this module under test/.

Grill Log

• Q: Why functions rather than a handler trait? A: A handler has one operation; a function value composes, stores in a builder, and closes over its own state without a type per handler. _Rejected:_ a trait with a send member.

Referenced by

[[architecture/_MOC]] · [[domain/Pipeline]] · [[seams/Handler]] · [[src/PuduLangHttpClient]] · [[src/PuduLangHttpClient/Client]] · [[src/PuduLangHttpClient/Events/Bus]] · [[src/PuduLangHttpClient/Factory]] · [[src/PuduLangHttpClient/Factory/Builder]] · [[src/PuduLangHttpClient/Factory/Entry]] · [[src/PuduLangHttpClient/Handlers/Authorization]] · [[src/PuduLangHttpClient/Handlers/Logging]] · [[src/PuduLangHttpClient/Handlers/Metrics]] · [[src/PuduLangHttpClient/Handlers/Propagation]] · [[src/PuduLangHttpClient/Handlers/Resilience]] · [[src/PuduLangHttpClient/Request]] · [[src/PuduLangHttpClient/Response]] · [[src/PuduLangHttpClient/Stub]] · [[src/PuduLangHttpClient/Transport]] · [[src/PuduLangHttpClient/_MOC]] · [[subsystems/Messages]]