string representation of set/record values

testsuite/string-representation/main.tri

···
   io::println!($"${'hello('world)}")
   io::println!($"${[]}")
   io::println!($"${[1, 2]}")
+  let set_string = $"${[|1, 2|]}"
+  assert set_string == "[|1, 2|]" || set_string == "[|2, 1|]"
+  let record_string = $"${{| 'a => 'b, 'c => 'd |}}"
+  assert record_string == "{|a => b, c => d|}" || record_string == "{|c => d, a => b|}"
 }

trilogy/src/stdlib/core.tri

···
     }
     str <> "]"
   }
+  case typeof 'set {
+    let mut str = "[|"
+    let mut i = 0
+    let arr = c::set_to_array!(val)
+    while i < c::length!(arr) {
+      str <>= $"${arr.i}"
+      i += 1
+      if i != c::length!(arr) {
+        str <>= ", "
+      }
+    }
+    str <> "|]"
+  }
+  case typeof 'record {
+    let mut str = "{|"
+    let mut i = 0
+    let arr = c::record_to_array!(val)
+    while i < c::length!(arr) {
+      str <>= $"${arr.i.'left} => ${arr.i.'right}"
+      i += 1
+      if i != c::length!(arr) {
+        str <>= ", "
+      }
+    }
+    str <> "|}"
+  }
   else then c::primitive_to_string!(val)