fixes, builtin function fixes, deep copy, string access

tests/test_code.lang

@@ -1,9 +1,9 @@
-basic (Float : #Ord #Div)
-basic (Int : #Ord #IDiv)
-basic (String : #Ord)
-basic (Char : #Ord #Enum)
-basic (Bool : #Ord)
-basic Unit
+basic (Float : #Ord #Div #Show)
+basic (Int : #Ord #IDiv #Show)
+basic (String : #Ord #Show #CharContainer)
+basic (Char : #Ord #Show)
+basic (Bool : #Ord #Show)
+basic (Unit : #Show)
 
 //
 
@@ -35,6 +35,12 @@ def ( || ) : x y =
 
 //
 
+typeclass CharContainer =
+  & var size : -> Int
+  & var at : Int -> Char
+
+//
+
 typeclass Move =
   & var ( <- ) : Move -> Unit // TODO
 
@@ -142,11 +148,11 @@ namespace var Ord {
 typeclass Show =
   & var show : -> String
 
-typeclass Read =
-  & var read : String -> Read
+// typeclass Read = // TODO
+//   & var read : String -> Read
 
-typeclass DebugShow =
-  & debug_show : -> String
+// typeclass DebugShow = // TODO
+//   & debug_show : -> String
 
 //
 
@@ -171,6 +177,12 @@ typeclass Enum =
 
 //
 
+decl print : String -> Unit
+decl scan : -> String
+decl random : -> Int // TODO
+
+//
+
 // // bad
 // typeclass Functor 'A =
 //   & fmap 'B ('F : (#Functor 'B)) : ('A -> 'B) -> Functor -> 'F
@@ -189,22 +201,21 @@ decl ( -- ) : Int -> Int -> Int_0
 def ( -- ) : begin end = {
   var current = begin
   return (while current < end do {
-    ; current += 1
-    bring current - 1
+    //; current += 1
+    //bring current - 1
+    bring 1
   })
 }
 
-decl print : String -> Unit
-decl scan : -> String
-
-decl func : String -> Int
-def func : s = {
+decl func : String -> Int -> Int
+def func : s i = {
   ; print: s
+  ; print: (i.show:)
   return 5
 }
 
 exec main {
-  for i in 0--9 do func: "abacaba"
+  for i in 0--9 do func: "abacaba" i
   ; print: ({
     if true then bring scan: else { ; print: "aaa" }
     bring "nothing"