Refine the heurstics used to disambiguate the parsing of types in regular expressions.

Add more test cases to the the pretty printer/parser test suite.

parser/parser.ml

@@ -85,6 +85,17 @@ let seq_of_string s =
   in
   aux (Encodings.Utf8.start_index s) (Encodings.Utf8.end_index s)
 
+let rec unseq e = match e with
+    Seq(Elem { descr = PatVar (ids, []); loc}, Arg (e0)) ->
+    let ue0 = unseq e0 in begin
+      match ue0 with
+      | Elem p -> Elem {loc; descr = PatVar(ids, prod_to_list p) }
+      | _ -> e
+    end
+  | Arg e -> unseq e
+  | _ -> e
+
+
 let parse_char loc s =
   match seq_of_string s with
     | [ c ] -> c
@@ -538,22 +549,20 @@ EXTEND Gram
           | _ -> Alt (x, y)
     ]
   | [ x = regexp; y = regexp -> re_seq x y ]
+  | [ x = regexp ; op = [  "->" -> "->" ] ; y = regexp ->
+      match unseq x, unseq y with
+      | Elem x , Elem y -> Elem (mk _loc (Arrow (x, y)))
+      | _ -> error _loc ( op ^ " not allowed in regular expression")
+    ]
   | [ x = regexp ; op = [ "&" -> "&" | "\\" -> "\\" ] ; y = regexp ->
-      let rec unseq e = match e with
-          Elem _ -> e
-        | Seq(Elem { descr = PatVar (ids, []); loc}, Arg (e0)) ->
-          let ue0 = unseq e0 in begin
-            match ue0 with
-            | Elem p -> Elem {loc; descr = PatVar(ids, prod_to_list p) }
-            | _ -> e
-          end
-        | _ -> e
-      in
       match unseq x, unseq y with
       | Elem x , Elem y ->
-        let res = if op = "&" then And (x, y) else Diff (x, y) in
+        let res =
+          if op = "&" then And (x, y) else Diff (x, y)
+        in
         Elem (mk _loc res)
-      | _ -> error _loc ( op ^ " not allowed in regular expression")
+      | _ ->
+        error _loc ( op ^ " not allowed in regular expression")
     ]
   | "capture" [ a = IDENT; "::"; x = regexp -> SeqCapture ((lop _loc,ident a),x) ]
   | [ x = regexp; "*" -> Star x

tests/printer/print.cd

@@ -14,6 +14,8 @@
 
 include "prologue.cd"
 
+(* Basic *)
+
 let x000 : Any = raise []
 let x001 : Int = raise []
 let x002 : Bool = raise []
@@ -31,4 +33,21 @@ let x013 : X1 where X1 = [ ( 'a \ [Any*] | X1)* ] = raise []
 let x014 : [ ( 'a \ [Any*] )* ] = raise []
 let x015 : X1  where X1 =  <a > [ X1* ] | <b foo=Int > [ X1* ]  = raise []
 let x016 : (Atom \ `A \`B) & ('a \ 'b \ 'c) = raise []
-let x017 : Atom \ ((`A | `B | `C)) | `test:A = raise []
+let x017 : Atom \ ((`A | `B | `C)) | `test:A = raise []
\ No newline at end of file
+
+(* Precedences   *)
+
+let x018 : 'a & 'b | 'c = raise []
+let x019 : 'a -> 'b | 'c = raise []
+let x020 : 'a -> 'b & 'c = raise []
+let x021 : 'a | 'b \ 'c = raise []
+let x022 : 'a -> 'b \ 'c = raise []
+
+(* Precedences in regexps *)
+
+let x023 : [ 'a & 'b | 'c ] = raise []
+let x024 : [ 'a -> 'b | 'c ] = raise []
+let x025 : [ ('a -> 'b) & 'c ] = raise []
+let x026 : [ 'a | 'b \ 'c ] = raise []
+let x027 : [ 'a -> 'b \ 'c ] = raise []
+let x028 : [ 'a -> (T ('a)) & 'c ] = raise []

tests/printer/prologue.cd

-namespace test = "test"
+namespace test = "test"
\ No newline at end of file
+
+type T('a) = (Int, 'a)

tests/printer/run.sh

@@ -20,7 +20,11 @@ do
     orig=`echo "$line" | sed -e "s/$REGEXP/\1/"`
     echo 'include "prologue.cd"' > "$TMP"
     echo "$line" >> "$TMP"
-    new=`"$CDUCE" -I "$DIR" --compile --verbose "$TMP" | sed -e 's/val x[0-9]\{3\} ://'`
+    new=`"$CDUCE" -I "$DIR" --compile --verbose "$TMP" | sed -e 's/val x[0-9]\{3\} ://' 2>/dev/null`
+    if test -z "$new"; then
+	cat "$TMP"
+	exit 3
+    fi
     rm -f "$TMP"o "$TMP"
 
     for test in "($orig) ($new)"  "($new) ($orig)"