1 files changed, 47 insertions, 0 deletions
diff --git a/tutorial/05_loops.sfinae b/tutorial/05_loops.sfinae
new file mode 100644
index 0000000..d974f99
--- /dev/null
+++ b/tutorial/05_loops.sfinae
@@ -0,0 +1,47 @@
+// lesson 5: loops
+//
+// ::repeat<V, ::sequence<...>> runs the sequence V times. that is the whole
+// loop. there is no index, no condition, no break.
+
+::repeat<
+    ::difference<'D', 'A'>,
+    ::sequence<
+        ::emit<
+            ::tuple<
+        ::integral_constant<::char, ::difference<'h', '\0'>>,
+        ::integral_constant<::char, ::difference<'i', '\0'>>
+            >
+        >::commit
+    >
+>::commit;
+
+// counting needs a variable, and changing a variable needs the undeclare dance,
+// and the dance needs a second variable to hold the value while the first one
+// is dead. this prints 1, 2, 3
+
+::declare<
+    ::name<'i'>,
+    ::decltype(::difference<'B', 'A'>)
+>::commit;
+
+::repeat<
+    ::difference<'D', 'A'>,
+    ::sequence<
+        ::emit<::decltype(::value_of<::name<'i'>>)>::commit,
+        ::declare<
+            ::name<'n', 'e', 'x', 't'>,
+            ::decltype(
+                ::sum<
+                    ::value_of<::name<'i'>>,
+                    ::difference<'B', 'A'>
+                >
+            )
+        >::commit,
+        ::undeclare<::name<'i'>>::commit,
+        ::declare<
+            ::name<'i'>,
+            ::decltype(::value_of<::name<'n', 'e', 'x', 't'>>)
+        >::commit,
+        ::undeclare<::name<'n', 'e', 'x', 't'>>::commit
+    >
+>::commit;