forall / ∀ syntactic sugar

src/Lib/Parser.idr

@@ -252,6 +252,15 @@ arrow : Parser Unit
 arrow = sym "->" <|> sym "→"
 
 -- Collect a bunch of binders (A : U) {y : A} -> ...
+
+forAll : Parser Raw
+forAll = do
+  keyword "forall" <|> keyword "∀"
+  all <- some (withPos varname)
+  keyword "."
+  scope <- typeExpr
+  pure $ foldr (\ (fc, n), sc => RPi fc (Just n) Implicit (RImplicit fc) sc) scope all
+
 binders : Parser Raw
 binders = do
   binds <- many (abind <|> ibind <|> ebind)
@@ -262,7 +271,9 @@ binders = do
     mkBind : FC -> (String, Icit, Raw) -> Raw -> Raw
     mkBind fc (name, icit, ty) scope = RPi fc (Just name) icit ty scope
 
-typeExpr = binders
+typeExpr
+  = binders
+  <|> forAll
   <|> do
         fc <- getPos
         exp <- term

src/Lib/Tokenizer.idr

@@ -8,10 +8,8 @@ import Lib.Common
 keywords : List String
 keywords = ["let", "in", "where", "case", "of", "data", "U", "do",
             "ptype", "pfunc", "module", "infixl", "infixr", "infix",
-            "->", "→", ":", "=>", ":=", "=", "<-", "\\", "_"]
-
-specialOps : List String
-specialOps = ["->", ":", "=>", ":=", "=", "<-"]
+            "∀", "forall", ".",
+             "->", "→", ":", "=>", ":=", "=", "<-", "\\", "_"]
 
 checkKW : String -> Token Kind
 checkKW s = if elem s keywords then Tok Keyword s else Tok Ident s
@@ -20,10 +18,10 @@ checkUKW : String -> Token Kind
 checkUKW s = if elem s keywords then Tok Keyword s else Tok UIdent s
 
 identMore : Lexer
-identMore = alphaNum <|> exact "." <|> exact "'" <|> exact "_"
+identMore = alphaNum <|> exact "'" <|> exact "_"
 
 singleton : Lexer
-singleton = oneOf "()\\{}[],?"
+singleton = oneOf "()\\{}[],?."
 
 quo : Recognise True
 quo = is '"'