Andreas Rumpf Araq

Cheap exceptions

Goals:

Avoid Rust's Option/Either manual error handling strategy.
Make exceptions cheaper.
Avoid error translation between Nim libraries by construction. The new vocabulary type ErrorCode is what should be used. Wrappers should translate errors to ErrorCode.
Make the error out of memory easier to handle.
Resolve once and for all the "error codes vs exceptions" choice.

	include prelude

	type
	Node {.acyclic.} = ref object
	le, ri: owned Node

	proc checkTree(n: Node): int =
	if n.le == nil: 1
	else: 1 + checkTree(n.le) + checkTree(n.ri)

	discard """
	cmd: "nim c --gc:orc $file"
	output: '''
	{"age": 12, "bio": "Я Cletus", "blob": [65, 66, 67, 128], "name": "Cletus"}
	true
	true
	alpha 100
	omega 200
	0'''
	"""


	import asynchttpserver, asyncdispatch, strutils, json, tables, streams

	# about 130 MB of alive data:
	var sessions: Table[string, JsonNode]

	for i in 0..<10:
	sessions[$i] = parseJson(newFileStream("1.json", fmRead), "1.json")

	var served = 0


	import macros

	macro awaitE(call: typed, r: untyped): untyped =
	let x = call[0]

	let tx = x.getType()
	expectKind tx, nnkBracketExpr
	var t = newTree(nnkProcTy)
	var p = newTree(nnkFormalParams, tx[1])


	import strutils, os

	type Target = tuple[repo, package, ext: string]

	proc newTarget*(path: string): Target =
	let splat = path.splitFile
	result = (repo: splat.dir, package: splat.name, ext: splat.ext)

	let mem = getOccupiedMem()


	const
	intrin = "<x86intrin.h>"
	{.localPassC: "-msse4.2".}
	type
	M128i {.importc: "__m128i", header: intrin, bycopy.} = object

	const
	SIDD_CMP_RANGES = 0b0000_0100'i32
	SIDD_NEGATIVE_POLARITY = 0b0001_0000'i32

	proc complement(s: set[char]): string =
	var last = '\0'
	result = ""
	for elem in '\0'..'\255':
	if elem notin s:
	if result.len == 0:
	result.add elem
	result.add elem
	elif pred(elem) == last:
	result[^1] = elem # patch last interval