1 files changed, 28 insertions, 12 deletions
diff --git a/stdlib/source/lux/control/parser/synthesis.lux b/stdlib/source/lux/control/parser/synthesis.lux
index f08159848..c36c61601 100644
--- a/stdlib/source/lux/control/parser/synthesis.lux
+++ b/stdlib/source/lux/control/parser/synthesis.lux
@@ -6,7 +6,13 @@
     ["." exception (#+ exception:)]]
    [data
     ["." error (#+ Error)]
-    [text
+    ["." bit]
+    ["." name]
+    [number
+     ["." i64]
+     ["." frac]
+     ["." nat]]
+    ["." text
      format]]
    [tool
     [compiler
@@ -56,8 +62,8 @@
       (#.Cons [head tail])
       (#error.Success [tail head]))))
 
-(template [<name> <tag> <type>]
-  [(def: #export <name>
+(template [<query> <assertion> <tag> <type> <eq>]
+  [(def: #export <query>
      (Parser <type>)
      (.function (_ input)
        (case input
@@ -65,17 +71,27 @@
          (#error.Success [input' x])
 
          _
+         (exception.throw ..cannot-parse input))))
+
+   (def: #export (<assertion> expected)
+     (-> <type> (Parser Any))
+     (.function (_ input)
+       (case input
+         (^ (list& (<tag> actual) input'))
+         (if (:: <eq> = expected actual)
+           (#error.Success [input' []])
+           (exception.throw ..cannot-parse input))
+
+         _
          (exception.throw ..cannot-parse input))))]
 
-  [bit /.bit Bit]
-  [i64 /.i64 (I64 Any)]
-  [f64 /.f64 Frac]
-  [text /.text Text]
-  [variant /.variant (Variant Synthesis)]
-  [local /.variable/local Nat]
-  [foreign /.variable/foreign Nat]
-  [constant /.constant Name]
-  [abstraction /.function/abstraction Abstraction]
+  [bit bit! /.bit Bit bit.equivalence]
+  [i64 i64! /.i64 (I64 Any) i64.equivalence]
+  [f64 f64! /.f64 Frac frac.equivalence]
+  [text text! /.text Text text.equivalence]
+  [local local! /.variable/local Nat nat.equivalence]
+  [foreign foreign! /.variable/foreign Nat nat.equivalence]
+  [constant constant! /.constant Name name.equivalence]
   )
 
 (def: #export (tuple parser)