sml_unit.sml

exception AssertionFailure of string;

fun assert_true( result : bool, message : string ) =   
  if result
  then result
  else raise AssertionFailure message

fun assert_false( result : bool, message : string ) = 
  if result
  then raise AssertionFailure message
  else result 

fun assert_equal( expected : int, result : int ) = 
  if expected = result
  then true
  else raise AssertionFailure ("expected " ^ Int.toString(result) ^ " to be " ^ Int.toString(expected) )

fun assert_equal_string( expected : string, result : string ) = 
  if expected = result
	then true
	else raise AssertionFailure ( "expected " ^ result ^ "to be " ^ expected )

fun to_string_date( date : int * int * int ) : string = 
	"(" ^ Int.toString(#1 date) ^ "," ^ Int.toString(#2 date) ^ "," ^ Int.toString(#3 date) ^ ")"

fun to_string( dates : (int * int * int) list) : string = 
	let 
		val mapped_dates = map to_string_date dates
		val result = String.concatWith "," mapped_dates
	in
	"[" ^ result ^ "]"
	end  

fun assert_equal_dates( expected: (int * int * int) list, result : (int * int * int) list  ) = 
  if expected = result
  then true
  else raise AssertionFailure ( "expected " ^ to_string(result) ^ " to be " ^ to_string(expected) )

fun int_list_to_string( items : int list ) = 
	let 
		val mapped_items = map Int.toString items
		val result = String.concatWith "," mapped_items
	in
		"[" ^ result ^ "]"
	end

fun assert_equal_ints( expected : int list, result : int list ) = 
	if expected = result
	then true
	else raise AssertionFailure ( 
		"expected " ^ int_list_to_string(result) ^ 
		" to be " ^ int_list_to_string(expected) )

fun assert_some_date( expected : int * int * int, result : (int * int * int) option ) = 
	if valOf(result) = expected
	then true
	else raise AssertionFailure ("expected " ^ to_string_date(valOf(result)) ^ 
		" to be " ^ to_string_date(expected) )

sml_unit_usage.sml

val test = assert_true( is_older( (1,2,3), (2,3,4) ), "one is older than another" );
val test = assert_true( is_older( (1,2,3), (1,3,3) ), "older only on month" );
val test = assert_true( is_older( (1,2,3), (1,2,4) ), "older only on day" );
val test = assert_true( is_older( (2011,3,31), (2011,4,28) ), "march is before february" );

OS.Process.exit(OS.Process.success);