f# higher order fn

gistfile1.fs

let names = ["alice"; "bob"; "carol"]
let name = List.tryFind (fun s -> length s < 4) names
match name with 
| Some n -> printfn "%s"  n
| None   -> printfn "They all have long names" 


// partial application 

let doubled = Seq.map (fun v -> v *2) values



// isDivisibleBy
let isDivisibleBy x y = y % x = 0

let evens = List.filter (isDivisibleBy 2) values // rather than (fun v -> isDivisibleBy 2 v) 


// takes a predicate, return a fn:
// val it: 'a list -> 'a list  
let except f = List.filter (not << f)

let numerics = List.filter isNumeric someList  // returns another list 

> List.filter 


var f = evaluator.makeEval (expressionText);
foreach (var variableAssignment in allVariableAssigntments){
    var result = f.Invoke(variableAssignment);
}