Max Moiseev moiseev

Introduce Sequence.filteredMap(_:)

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	public protocol Dividable {
	static func / (lhs: Self, rhs: Self) -> Self
	}

	extension Int : Dividable {}
	extension Double : Dividable {}

	extension Sequence where Element : Numeric & Dividable {
	func average() -> Element {
	var i: Element = 0


	def append(xs, yss):
	return [[x] + ys for x in xs for ys in yss]

	def make_lists(*xss):
	if len(xss) == 1:
	return [[x] for x in xss[0]]
	h, t = xss[0], xss[1:]
	return append(h, make_lists(*t))

	type IClauseVisitor<'TState> =
	abstract member Simple : String array * Condition * Val -> 'TState
	abstract member Complex : 'TState * LogicalOperation * 'TState -> 'TState

	let visitClause (visitor:#IClauseVisitor<'TState>) clause =
	let simpleF props (cond:Cond) value = visitor.Simple(props, (cond.ToEnum()), value)
	let complexF left (logOp:LogOp) right = visitor.Complex(left, (logOp.ToEnum()), right)
	Clause.Fold simpleF complexF clause

	let toExpr (par:ParameterExpression) (clause: Clause) =
	let constExpr (x:'a) =
	Expression.Constant(x, typeof<'a>) \|> asExpr
	let callExpr (i:Expression) (m:String) (p:Expression) =
	Expression.Call(i, m, Array.empty, p)
	let arrExpr (xs:'a array) =
	Expression.NewArrayInit(typeof<'a>, Array.map (constExpr >> asExpr) xs) \|> asExpr
	let inExpr (vEx:Expression) (arrEx:Expression) =
	Expression.Call(typeof<Enumerable>, "Contains", [\|vEx.Type\|], arrEx, vEx) \|> asExpr

	let foldClause simpleF complexF clause =
	let unitem = function
	\| Prop ss -> ss
	let rec loop clause cont =
	match clause with
	\| Simple (item, condition, value) ->
	cont (simpleF (unitem item) condition value)
	\| Complex (l, op, r) ->
	loop l (fun lval ->
	loop r (fun rval ->

	string[] strings = new string[] { "1", "123", "12", "12ab", "a", "ab", "abc" };
	var res = strings.Where("Length >= 3");