System I/O and Networking

System I/O (import System)

Implementation status: File read/write/exists/copy Implemented; readAsync goes to the blocking pool awaitable, not an epoll reactor GA. Http.serve lives under Networking (default back end = hyper+tokio). Same-port HMR product-path automation, overlapping accept, in-process HTTPS GET, and upgradeTerminate frame paths are met as pinned elsewhere — still ≠ browser Playwright GA / full concurrency SLA / WSS product GA.

import System

func main() {
    File.write(path: "/tmp/syx-io-demo.txt", content: "hi")
    print(File.read(path: "/tmp/syx-io-demo.txt"))
}

Examples: examples/file_tool/ · examples/io_demo.sy

Public types: File, Directory, Stdin, FilePath (import System).

Networking (import Networking)

Implementation status: Http / Url return HTTPResponse / Url; TLS client real path; not server TLS GA, not streaming body. WebSocket / gRPC narrowed surfaces exist as opt-in experimental paths; still not product GA.

import Networking

func main() {
    let r = Http.fetch(url: "https://example.com")
    print(r.status)
}

Examples: examples/http_tool/ · examples/http_server_tool/ · examples/httpclient_demo.sy

API	Notes
Http.fetch(url:)	GET; single labeled url argument
Http.post(url:body:)	POST body as String
Url	Parse / components
UdpSocket.bind / sendTo / recvFrom	Host id Int; recvFrom → Dictionary (R-7; ≠ Object bag)
HttpBodyStream.open / openWithOptions	→ Dictionary (handle/status; R-8); access via opened["handle"]
Url.encodeQuery / Url.build	query: Dictionary (R-9; ≠ Object)
WebSocket.connect / send / recv / close	session bag Dictionary (R-10; ≠ Object; ≠ WSS GA); access via ws["url"]

Loopback positive cases can be configured with SYX_EC_M2_1_HTTP_BASE. The request-count ceiling of Http.serve is set by SYX_HTTP_SERVE_MAX_REQUESTS (≠ graceful Http.shutdown GA).