A map function takes an array, a variable and an expression and returns an array where the expression was applied to every array element. E.g.: Assume that 'x' is an integer variable. Now

doMap([](1, 2, 4, 6, 10, 12, 16), x, x + 1)

will add 1 to every element in the array. Therefore it will return

[](2, 3, 5, 7, 11, 13, 17)

The variable 'x' is used as input parameter for the expression 'x + 1'. The function 'doMap' is not predefined, but it can be defined with:

const func array integer: doMap (in array integer: anArray,
    inout integer: aVariable, ref func integer: anExpression) is func

  result
    var array integer: mappedArray is 0 times 0;
  begin
    for aVariable range anArray do
      mappedArray &:= anExpression;
    end for;
  end func;

Note that the call of 'doMap' works without lambda expression. Instead 'doMap' is defined with the call-by-name parameter 'anExpression'. The parameter 'aVariable' is the input parameter for 'anExpression'.