October commit

- custom parser support and infra
- type-tagging and traits (untested)
- match expressions

examples/match/main.orc

@@ -0,0 +1,21 @@
+import std::to_string
+
+const foo := t[option::some "world!", option::none]
+
+const test1 := match foo { 
+  t[option::some balh, option::none] => balh;
+}
+
+const bar := map::new[
+  "age" = 22,
+  "name" = "lbfalvy",
+  "is_alive" = true,
+  "species" = "human",
+  "greeting" = "Hello"
+]
+
+const test2 := match bar {
+  map::having ["is_alive" = true, "greeting" = foo] => foo
+}
+
+const main := test2 ++ ", " ++ test1