Wren Tutorial: Core to Advanced

Basics

Wren: OOP scripting. Classes: class Name { construct new(args) { _vars } methods }. Inherit: is Super. Fn: Fn.new { |args| body }. Import: import "mod" for Items. Vars: var x = val. Loops: for (i in seq) { }, while (cond) { }. Conditionals: if/else. Errors: Fiber.abort("msg").

Example:

class Point {
  construct new(x, y) { _x = x; _y = y }
  x { _x }
}
var p = Point.new(1, 2)
System.print(p.x) // 1

Core Classes

  • Bool/Fiber/Fn/Null/Num: Base.
  • Sequence: all/any(f), contains(el), count/f, each(f), isEmpty, map(f), skip/take(n), where(f), reduce/acc+f, join/sep, toList.
  • String: bytes/codePoints (seqs), split(delim), replace(from/to), trim/chars/start/end, *(n).
  • List: addAll(other), sort/comparer (quicksort), toString, +/ *(other/n).
  • Map: keys/values (seqs), toString, iteratorValue → MapEntry(key/val).
  • Range: Seq empty.
  • System: print/obj/All, write/obj/All, clock.

Meta/Random

  • Meta: getModuleVariables(mod), eval(src), compileExpression/src.
  • Random: new/seed, float/int/range, sample(list/n), shuffle(list).

IO/OS

  • File: read/write(path), exists/delete.
  • Directory: list/exists/mkdir/rmdir/delete(path).
  • Stdin/Stdout: readLine, flush.
  • Process: args, timed exec.

Fibers/Scheduler/Timer

  • Fiber: new { body }, call/try.
  • Scheduler: add { body } (runs on IO).
  • Timer: sleep(ms) (suspends).

Modules/Examples

  • Argparse: new(desc), addArgument(opt, {help/default/action/type}), parseArgs(args) → map.
  • Base64: encode/decode(str), encodeUrl/decodeUrl.
  • Bytes: fromList/toList, length/concat/slice, xorMask(payload/mask).
  • Crypto: randomBytes(n)/Int(min,max); Hash: md5/sha1/sha256(str), toHex.
  • Dataset: memory()["table"]: insert(map) → uid, all/find(query)/findOne, update/delete(uid), columns/tables.
  • Datetime: now/fromTimestamp, components, format(fmt), +/- Duration (fromHours/etc, seconds/+/-/*).
  • Dns: lookup(host,4/6) → [ips].
  • Pathlib: new(path), exists/isDir/File, expanduser/glob/rglob, iterdir/joinpath/match/mkdir, name/stem/suffix/es, parent/parents/parts, readText/writeText/unlink, relativeTo/rename/walk, withName/Stem/Suffix.
  • Regex: new(pat/flags), test/replace/All/split.
  • Signal: Constants (SIGINT=2, etc.).
  • Sqlite: memory(): execute(sql,params), lastInsertId/changes, query → rows.
  • String Utils: toLower/Upper/hexEncode/Decode/repeat/padLeft/Right/escapeHtml/Json/urlEncode/Decode.
  • Strutil: As above.
  • Subprocess: run(cmd/args) → ProcessResult(success/exitCode/stdout).
  • Tempfile: gettempdir/mkdtemp/stemp/temp(suffix/prefix/dir), NamedTemporaryFile/TemporaryDirectory (name/write/read/close/delete/use/cleanup).
  • Uuid: v4() → str, isValid/V4.
  • Wdantic: Schema: new({field: Field.type(opts)}), validate(data) → ValidationResult(isValid/errors/data); Validators: email/domain/etc.
  • Web: Client: parseUrl_(url) → {scheme/host/port/path}; Request: new_(method/path/query/headers/body/params/files), header/json/cookies/form; Response: text/html/json/redirect/new(status/body/header/cookie/build); Router: new(), get/post/etc(path,handler), match(method/path) → {handler/params}; SessionStore: create/get/save/destroy.
  • Websocket: computeAcceptKey(base64), Message: new_(opcode/payload/fin), isText/etc; Server: bind/accept/receive/sendBinary/close.

Tests/Benchmarks

  • Fib: Recursive fib(28).
  • Nbody: Solar system sim (bodies, energy, advance).
  • Demos: Animals game (tree nodes), chat server (TCP fibers), browser auto (WS commands), etc.

Usage

Import modules, use classes/fns. Run: Compile/eval via Meta. Async: Fibers + Scheduler/Timer.

Feature-Packed Example

import "io" for File, Directory, Stdin
import "timer" for Timer
import "scheduler" for Scheduler
import "random" for Random
import "meta" for Meta
import "os" for Process

class Demo is Sequence {
  construct new() { _list = [1,2,3] }
  iterate(i) { _list.iterate(i) }
  iteratorValue(i) { _list.iteratorValue(i) * 2 }
}

var rand = Random.new()
System.print(rand.int(10)) // Random num

var seq = Demo.new()
System.print(seq.map { |x| x + 1 }.toList) // [3,5,7]

Scheduler.add {
  Timer.sleep(100)
  System.print("Async fiber")
}

var modVars = Meta.getModuleVariables("io")
System.print(modVars) // Module vars

var file = "temp.txt"
File.create(file) { |f| f.writeBytes("data") }
System.print(File.read(file)) // data
File.delete(file)

var sub = Subprocess.run("echo hello")
System.print(sub.stdout.trim()) // hello

System.print(Process.args) // Args