diff --git a/src/Data/Syntax/Assignment.hs b/src/Data/Syntax/Assignment.hs
index 58d1fb91e..618ea406f 100644
--- a/src/Data/Syntax/Assignment.hs
+++ b/src/Data/Syntax/Assignment.hs
@@ -2,6 +2,7 @@
 module Data.Syntax.Assignment
 ( Assignment
 , get
+, state
 , symbol
 , range
 , sourceSpan
@@ -23,9 +24,9 @@ import Data.Functor.Foldable hiding (Nil)
 import Data.Record
 import Data.Text (unpack)
 import qualified Info
-import Prologue hiding (Alt, get)
+import Prologue hiding (Alt, get, state)
 import Range (offsetRange)
-import Source (Source(), drop, slice, sourceText)
+import qualified Source (Source(..), drop, slice, sourceText)
 import Text.Parser.TreeSitter.Language
 import Text.Show hiding (show)
 
@@ -36,6 +37,7 @@ type Assignment node = Freer (AssignmentF node)
 
 data AssignmentF node a where
   Get :: AssignmentF node node
+  State :: AssignmentF (Node grammar) (AssignmentState grammar)
   Source :: AssignmentF symbol ByteString
   Children :: Assignment symbol a -> AssignmentF symbol a
   Alt :: a -> a -> AssignmentF symbol a
@@ -47,6 +49,12 @@ data AssignmentF node a where
 get :: Assignment (Record fields) (Record fields)
 get = Get `Then` return
 
+-- | Zero-width production of the current state.
+--
+--   Since this is zero-width, care must be taken not to repeat it without chaining on other rules. I.e. 'many (state *> b)' is fine, but 'many state' is not.
+state :: Assignment (Node grammar) (AssignmentState grammar)
+state = State `Then` return
+
 -- | Zero-width match of a node with the given symbol.
 --
 --   Since this is zero-width, care must be taken not to repeat it without chaining on other rules. I.e. 'many (symbol A *> b)' is fine, but 'many (symbol A)' is not.
@@ -89,7 +97,7 @@ data Result a = Result a | Error [Text]
 
 
 -- | Run an assignment of nodes in a grammar onto terms in a syntax, discarding any unparsed nodes.
-assignAll :: (Symbol grammar, Eq grammar, Show grammar) => Assignment (Node grammar) a -> Source -> [AST grammar] -> Result a
+assignAll :: (Symbol grammar, Eq grammar, Show grammar) => Assignment (Node grammar) a -> Source.Source -> [AST grammar] -> Result a
 assignAll assignment = (assignAllFrom assignment .) . AssignmentState 0 (Info.SourcePos 0 0)
 
 assignAllFrom :: (Symbol grammar, Eq grammar, Show grammar) => Assignment (Node grammar) a -> AssignmentState grammar -> Result a
@@ -104,9 +112,10 @@ runAssignment :: (Symbol grammar, Eq grammar, Show grammar) => Assignment (Node
 runAssignment = iterFreer (\ assignment yield state -> case (assignment, dropAnonymous state) of
   -- Nullability: some rules, e.g. 'pure a' and 'many a', should match at the end of input. Either side of an alternation may be nullable, ergo Alt can match at the end of input.
   (Alt a b, state) -> yield a state <|> yield b state -- FIXME: Symbol `Alt` Symbol `Alt` Symbol is inefficient, should build and match against an IntMap instead.
+  (State, state) -> yield state state
   (assignment, AssignmentState offset _ source (subtree@(Rose node@(_ :. range :. _) children) : _)) -> case assignment of
     Get -> yield node state
-    Source -> yield (sourceText (slice (offsetRange range (negate offset)) source)) (advanceState state)
+    Source -> yield (Source.sourceText (Source.slice (offsetRange range (negate offset)) source)) (advanceState state)
     Children childAssignment -> do
       c <- assignAllFrom childAssignment state { stateNodes = children }
       yield c (advanceState state)
@@ -125,7 +134,7 @@ advanceState state@AssignmentState{..}
   | Rose (_ :. range :. span :. _) _ : rest <- stateNodes = AssignmentState (Info.end range) (Info.spanEnd span) (Source.drop (Info.end range - stateOffset) stateSource) rest
   | otherwise = state
 
-data AssignmentState grammar = AssignmentState { stateOffset :: Int, statePos :: Info.SourcePos, stateSource :: Source, stateNodes :: [AST grammar] }
+data AssignmentState grammar = AssignmentState { stateOffset :: Int, statePos :: Info.SourcePos, stateSource :: Source.Source, stateNodes :: [AST grammar] }
   deriving (Eq, Show)
 
 instance Alternative (Assignment symbol) where
@@ -135,6 +144,7 @@ instance Alternative (Assignment symbol) where
 instance Show symbol => Show1 (AssignmentF symbol) where
   liftShowsPrec sp sl d a = case a of
     Get -> showString "Get"
+    State -> showString "State" . sp d (AssignmentState 0 (Info.SourcePos 0 0) (Source.Source "") [])
     Source -> showString "Source" . showChar ' ' . sp d ""
     Children a -> showsUnaryWith (liftShowsPrec sp sl) "Children" d a
     Alt a b -> showsBinaryWith sp sp "Alt" d a b