Add list sugar

src/Lib/Syntax.newt

@@ -60,6 +60,7 @@ data Raw : U where
   -- has to be applied or we have to know its type as Foo → Foo to elaborate.
   -- I can bake the arg in here, or require an app in elab.
   RUpdateRec : (fc : FC) → List UpdateClause → Maybe Raw → Raw
+  RList : (fc : FC) → Maybe Raw → Raw
 
 instance HasFC Raw where
   getFC (RVar fc nm) = fc
@@ -78,6 +79,7 @@ instance HasFC Raw where
   getFC (RAs fc _ _) = fc
   getFC (RUpdateRec fc _ _) = fc
   getFC (RImpossible fc) = fc
+  getFC (RList fc _) = fc
 
 data Import = MkImport FC (FC × Name)
 
@@ -189,6 +191,8 @@ instance Pretty Raw where
     asDoc p (RWhere _ dd b) = text "TODO pretty RWhere"
     asDoc p (RAs _ nm x) = text nm ++ text "@(" ++ asDoc 0 x ++ text ")"
     asDoc p (RUpdateRec _ clauses tm) = text "{" <+> text "TODO RUpdateRec" <+> text "}"
+    asDoc p (RList _ (Just t)) = text "[" <+> asDoc p t <+> text "]"
+    asDoc p (RList _ Nothing) = text "[]"
 
 prettyBind : (BindInfo × Raw) -> Doc
 prettyBind (BI _ nm icit quant, ty) = wrap icit (text (show quant ++ nm) <+> text ":" <+> pretty ty)
@@ -246,6 +250,8 @@ substRaw ss t = case t of
   (RWhere fc ds body) => RWhere fc (map substDecl ds) (substRaw ss body)
   (RDo fc stmts) => RDo fc (substStmts ss stmts)
   (RCase fc scrut mdef alts) => RCase fc (substRaw ss scrut) (map (substRaw ss) mdef) (map substAlt alts)
+  (RList fc (Just t)) => RList fc (Just $ substRaw ss t)
+  (RList fc Nothing) => RList fc Nothing
   -- Enumerate to force consideration of new cases
   t@(RImpossible _) => t
   t@(RU _) => t