Add case over int.

1 files changed, 18 insertions, 8 deletions

diff --git a/parser.sml b/parser.sml
index 6efc4aa..3c044af 100644
--- a/parser.sml
+++ b/parser.sml
@@ -275,9 +275,10 @@ struct
         List.exists (fn c => c = start) symbolicIdentifierLetters
     in
       lexeme
-        (try (parseString s) >>
-        notFollowedBy (if isSymbolic then symbolicIdentifierLetter else alphaNumIdentifierLetter) >>
-        const s)
+        (try
+          (parseString s >>
+          notFollowedBy (if isSymbolic then symbolicIdentifierLetter else alphaNumIdentifierLetter) >>
+          const s))
       <?> s
     end
 
@@ -349,6 +350,7 @@ struct
 
   val rec atpat : Syntax.pat parser = fn st =>
       (Syntax.PWild <$ reserved "_"
+  <|> Syntax.PInt <$> integer
   <|> between (symbol "(") (symbol ")") pat
   <|> Syntax.PVar <$> identifier) st
   and pat : Syntax.pat parser = fn st => atpat st
@@ -437,16 +439,24 @@ struct
           bind orelseExpr (fn e2 =>
           const (Syntax.EOrElse (e1, e2))))
       <|> const e1) st
-  and handleExpr : Syntax.expr parser = fn st => orelseExpr st
-  and raiseExpr : Syntax.expr parser = fn st => handleExpr st
-  and fnExpr : Syntax.expr parser = fn st =>
+  and expr : Syntax.expr parser = fn st =>
       ((reserved "fn" >>
       bind pat (fn p =>
       reserved "=>" >>
       bind expr (fn e =>
       const (Syntax.ELambda (p, e)))))
-  <|> raiseExpr) st
-  and expr : Syntax.expr parser = fn st => fnExpr st
+  <|> (reserved "case" >>
+      bind expr (fn e =>
+      reserved "of" >>
+      bind
+        (sepBy1
+            (bind pat (fn p =>
+            reserved "=>" >>
+            bind expr (fn e =>
+            const (p, e))))
+          (reserved "|")) (fn arms =>
+      const (Syntax.ECase (e, arms)))))
+  <|> orelseExpr) st
   and dec : Syntax.dec parser = fn st =>
     (reserved "val" >>
     bind pat (fn p =>