add some keywords

src/Quox/Lexer.idr

@@ -71,7 +71,10 @@ skip : Lexer -> Tokenizer (Maybe a)
 skip lex = match lex $ const Nothing
 
 simple : List String -> a -> Tokenizer (Maybe a)
-simple str = match (choice $ map exact str) . const . Just
+simple strs = match (choice $ map exact strs) . const . Just
+
+keyword : String -> Keyword -> Tokenizer (Maybe Token)
+keyword str = match (exact str <+> reject nameCont) . const . Just . K
 
 choice : (xs : List (Tokenizer a)) -> {auto 0 _ : NonEmpty xs} -> Tokenizer a
 choice (t :: ts) = foldl (\a, b => a <|> b) t ts
@@ -100,6 +103,10 @@ tokens = choice [
   simple ["<<", "⊲"] $ P Triangle,
   match wild $ const $ P Wild,
 
+  keyword "fun"  Fun,  keyword "λ"  Fun,
+  keyword "let"  Let,  keyword "in" In,
+  keyword "case" Case, keyword "of" Of,
+
   match name   $ Name,
   match symbol $ Symbol . assert_total strTail,
 

tests/src/Tests/Lexer.idr

@@ -109,6 +109,16 @@ tests = "lexer" :- [
     rejects'     "1abc"
   ],
 
+  "keywords" :- [
+    acceptsWith' "fun"  [K Fun],
+    acceptsWith' "λ"    [K Fun],
+    acceptsWith' "let"  [K Let],
+    acceptsWith' "in"   [K In],
+    acceptsWith' "case" [K Case],
+    acceptsWith' "of"   [K Of],
+    acceptsWith' "funk" [Name "funk"]
+  ],
+
   "numbers" :- [
     acceptsWith' "0"      [N Zero],
     acceptsWith' "1"      [N One],