1 files changed, 44 insertions, 0 deletions
diff --git a/stdlib/source/library/lux/control/parser/environment.lux b/stdlib/source/library/lux/control/parser/environment.lux
new file mode 100644
index 000000000..c0ced37c2
--- /dev/null
+++ b/stdlib/source/library/lux/control/parser/environment.lux
@@ -0,0 +1,44 @@
+(.module:
+  [library
+   [lux #*
+    [control
+     ["." try (#+ Try)]
+     ["." exception (#+ exception:)]]
+    [data
+     ["." product]
+     ["." text
+      ["%" format (#+ format)]]
+     [collection
+      ["." dictionary (#+ Dictionary)]]]]]
+  ["." //])
+
+(type: #export Property
+  Text)
+
+(type: #export Environment
+  (Dictionary Property Text))
+
+(exception: #export (unknown {property Property})
+  (exception.report
+   ["Property" (%.text property)]))
+
+(type: #export (Parser a)
+  (//.Parser Environment a))
+
+(def: #export empty
+  Environment
+  (dictionary.new text.hash))
+
+(def: #export (property name)
+  (-> Text (Parser Text))
+  (function (_ environment)
+    (case (dictionary.get name environment)
+      (#.Some value)
+      (exception.return [environment value])
+      
+      #.None
+      (exception.throw ..unknown name))))
+
+(def: #export (run parser environment)
+  (All [a] (-> (Parser a) Environment (Try a)))
+  (\ try.monad map product.right (parser environment)))