Some more Patterns work

-at first brush, a pattern is like a single Variant with a list of free
vars

schala-lang/src/ast.rs

@@ -132,7 +132,8 @@ pub struct Guard {
 
 #[derive(Debug, PartialEq, Clone)]
 pub struct Pattern {
-
+  pub free_vars: Vec<Rc<String>>,
+  pub var: Variant,
 }
 
 #[derive(Debug, PartialEq, Clone)]

schala-lang/src/parsing.rs

@@ -678,7 +678,10 @@ impl Parser {
 
   parse_method!(pattern(&mut self) -> ParseResult<Pattern> {
     let identifier = self.identifier()?;
-    Ok(Pattern {  })
+    Ok(Pattern {
+      free_vars: vec![],
+      var: Variant::UnitStruct(identifier)
+    })
   });
 
   parse_method!(block(&mut self) -> ParseResult<Block> {