Show instances, fixed a bunch of bugs in parsing

- The case / let / indent stuff actually works
- Needed a bunch of defers
- Idris silently builds loops in immediate definitions

src/Syntax.idr

@@ -1,7 +1,16 @@
 module Syntax
 
+import Data.String
+import Derive
+
+
 -- Good enough start, lets parse
 -- This is informed by pi-forall and others and is somewhat low level
+-- %language ElabReflection
+-- %logging "foo" 19
+
+%hide Name
+%hide Decl
 
 Name = String
 
@@ -9,8 +18,11 @@ data Term : Type where
 
 TyTerm = Term
 
+public export
 data Literal = LString String | LInt Int | LBool Bool
+public export
 data RigCount = Rig0 | RigW
+public export
 data Plicity = Implicit | Explicit | Eq
 
 public export
@@ -20,6 +32,8 @@ data Pattern
   | PatWild
   | PatLit Literal
 
+-- %runElab deriveShow `{Pattern}
+
 -- could be a pair, but I suspect stuff will be added?
 public export
 data CaseAlt = MkAlt Pattern Term
@@ -29,7 +43,7 @@ data Term
   = Var Name
   | Ann Term TyTerm
   | Lit Literal
-  | Let Name Term Term
+  | Let (List (Name, Term)) Term
   | Pi Name Plicity Term Term
   | App Term Term
   | Lam Pattern Term
@@ -56,3 +70,47 @@ record Module where
   name : Name
   imports : List Name
   decls : List Decl
+
+foo : List String -> String
+foo ts = "(" ++ unwords ts ++ ")"
+
+mutual
+
+  Show RigCount where
+    show Rig0 = "Rig0"
+    show RigW = "RigW"
+
+  Show Pattern where
+    show (PatVar str) = foo ["PatVar", show str]
+    show (PatCon str xs) = foo ["PatCon", show str, assert_total $ show xs]
+    show PatWild = "PatWild"
+    show (PatLit x) = foo ["PatLit" , show x]
+
+
+  Show CaseAlt where
+    show (MkAlt x y)= foo ["MkAlt", show x, assert_total $ show y]
+
+  Show Plicity where
+    show Implicit = "Implicit"
+    show Explicit = "Explicit"
+    show Eq = "Eq"
+
+  Show Literal where
+    show (LString str) = foo [ "LString", show str]
+    show (LInt i) = foo [ "LInt", show i]
+    show (LBool x) = foo [ "LBool", show x]
+
+
+  export
+  Show Term where
+    show (Var name) = foo ["Var", show name]
+    show (Ann t ty) = foo [ "Ann", show t, show ty]
+    show (Lit x) = foo [ "Lit", show x]
+    show (Let alts y) = foo [ "Let", assert_total $ show alts, show y]
+    show (Pi str x y z) = foo [ "Pi", show str, show x, show y, show z]
+    show (App x y) = foo [ "App", show x, show y]
+    show (Lam x y) = foo [ "Lam", show x, show y]
+    show (Case x xs) = foo [ "Case", show x, show xs]
+    show Wildcard = "Wildcard"
+    show (ParseError str) = foo [ "ParseError", "str"]
+