Ignore defaults values in parameter type check

ast/ArgumentTuple.lua

@@ -150,8 +150,8 @@ ArgumentTuple = ast.abstract.Node {
 			end
 			-- not found
 			if not arg then return false, ("missing parameter %s"):format(param.identifier:format(state)) end
-			-- type check
+			-- type check (assume ok for default values)
-			if param.type_check then
+			if param.type_check and arg ~= param.default then
 				local r = param.type_check:call(state, ArgumentTuple:new(arg))
 				if not r:truthy() then return false, ("type check failure for parameter %s in function %s"):format(param.identifier:format(state), params:format(state)) end
 				if Number:is(r) then

test/results/function type dispatch with default.ans

@@ -0,0 +1,20 @@
+--# run #--
+--- text ---
+| {}"a"|
+--- text ---
+| {}"x"|
+--- text ---
+| {}"a"|
+--- text ---
+| {}"" {}"gs" {}""|
+| {}"" {}"gn" {}""|
+| {}"" {}"gs" {}""|
+| {}"" {}"gn" {}""|
+| {}"" {}"gs" {}""|
+| {}"" {}"gn" {}""|
+| {}"" {}"gs" {}""|
+| {}"" {}"gn" {}""|
+--- return ---
+()
+--# saved #--
+{}

test/tests/function type dispatch with default.ans

@@ -0,0 +1,26 @@
+:$ fn(x::number)
+	|x
+
+:$ fn(a::string="o")
+	|a
+
+fn("s")
+
+fn(5)
+
+fn()
+
+:$ g(n="s", a::number=5)
+	@"gn"
+
+:$ g(n="s", a::string="lol")
+	@"gs"
+
+|{g(n="k", a="l")}
+|{g(n="k", a=1)}
+|{g(n="k", "l")}
+|{g(n="k", 1)}
+|{g("k", "l")}
+|{g("k", 1)}
+|{g("k", a="l")}
+|{g("k", a=1)}