/* Unit Test: First-Class Functions */
/* Tests: Function references, higher-order functions */

/* Basic functions */
double : x -> x * 2;
square : x -> x * x;
add1 : x -> x + 1;

/* Function references */
double_ref : @double;
square_ref : @square;
add1_ref : @add1;

/* Test function references */
result1 : double_ref 5;
result2 : square_ref 3;
result3 : add1_ref 10;

..assert result1 = 10;
..assert result2 = 9;
..assert result3 = 11;

/* Higher-order functions using standard library */
composed : compose @double @square 3;
piped : pipe @double @square 2;
applied : apply @double 7;

..assert composed = 18;
..assert piped = 16;
..assert applied = 14;

/* Function references in case expressions */
getFunction : type -> 
  when type is
    "double" then @double
    "square" then @square
    _        then @add1;

func1 : getFunction "double";
func2 : getFunction "square";
func3 : getFunction "unknown";

result4 : func1 4;
result5 : func2 4;
result6 : func3 4;

..assert result4 = 8;
..assert result5 = 16;
..assert result6 = 5;

..out "First-class functions test completed";