What's new?

Version 3.0

• Automatic inference for lambda argument types:

    new [1; 2; 3; 4; 5]
        |> Where (x -> x**2 < 10) // x is inferred to be int
  

• Full support for variadic functions and constructors

• Instantiation of empty arrays by size, like in C#

• Partial application for any callable types:

    let sum = (x:int y:int) -> x + y
    let add3 = sum _ 3
  

• Underscore name for unneeded arguments in lambdas and functions

Fixed bugs:

• Loop variables are now closured correctly
• Calling a method of a base interface type on derived one now works
• Built-in types now work properly in saved assemblies

Version 2.0

• The parser has been completely rewritten:

  • FSharp and FParsec dependencies removed
  • Huge speed-up
  • Improved error reporting
  • The entire compiler is now a single assembly of 270 kb.

• The for loop that works as both for and foreach loops:

    for a in 1..10 do
        print "a"
  

• The pure modifier enables automatic memoization for a function

• Unitialized variables: var x : int

• Multiline object initializers

    var x = new [
        "hello there"
        fmt "{0}, {1} and {2}" 1 true 2.5
    ]
  

• Various syntax improvements:

  • Function definitions became more clear with arguments in parens:

      fun add:int (x:int y:int) -> x + y
    

  • No braces around the single argument of a lambda:

      getPoints ()
          |> Where (p:Point -> p.X < 10)
          |> Select (p:Point -> fmt "{0}:{1}" p.X p.Y)
    

  • No braces for if, while and catch:

      try
          if a > 10 then
              fail "error"
          else
              while a < 10 do
                  println "a = {0}" a
                  a = a + 1
      catch e:Exception
          print "fail: {0}" e.Message
    

Version 1.1

• Constant expressions are evaluated at compile time
• finally keyword for the try block
• Several bugfixes

Version 1.0

Initial LENS compiler version.