WIP zero-width pattern tests pass

Author: jamesdbrock

src/Parsing/String/Replace.purs

@@ -320,31 +320,33 @@ splitCapCombinator
   => ParserT String m a
   -> ParserT String m {carry::Maybe CodePoint,rlist::List (Tuple String a),arraySize::Int}
 
-splitCapCombinator sep = tailRecM accum {lastPosIndex:0,carry:Nothing,rlist:Nil,arraySize:0}
+splitCapCombinator sep = tailRecM accum {carry:Nothing,rlist:Nil,arraySize:0}
   where
-    accum :: {lastPosIndex::Int,carry::Maybe CodePoint,rlist::List (Tuple String a),arraySize::Int} -> ParserT String m (Step {lastPosIndex::Int,carry::Maybe CodePoint,rlist::List (Tuple String a),arraySize::Int} {carry::Maybe CodePoint,rlist::List (Tuple String a),arraySize::Int})
-    accum {lastPosIndex,carry,rlist,arraySize} = do
-      optionMaybe (try $ anyTill sep) >>= case _ of
-        Just (Tuple unmatched matched) -> do
-          Position {index:posIndex} <- position
+    posSep = do
+      Position {index:posIndex1} <- position
+      x <- sep
+      Position {index:posIndex2} <- position
+      pure $ posIndex1 /\ x /\ posIndex2
+    accum :: {carry::Maybe CodePoint,rlist::List (Tuple String a),arraySize::Int} -> ParserT String m (Step {carry::Maybe CodePoint,rlist::List (Tuple String a),arraySize::Int} {carry::Maybe CodePoint,rlist::List (Tuple String a),arraySize::Int})
+    accum {carry,rlist,arraySize} = do
+      optionMaybe (try $ anyTill posSep) >>= case _ of
+        Just (Tuple unmatched (posIndex1 /\ matched /\ posIndex2)) -> do
           let
             carry_unmatched = case carry of
               Nothing -> unmatched
               Just cp -> CodePoint.singleton cp <> unmatched
-          if posIndex == lastPosIndex then do
+          if posIndex2 == posIndex1 then do
             -- sep succeeded but consumed no input, so advance by one codepoint and
             -- carry the codepoint over to cons to the next unmatched
             carryNext <- optionMaybe anyCodePoint
             pure $ Loop
-              { lastPosIndex: posIndex+1
-              , carry: carryNext
+              { carry: carryNext
               , rlist: (Tuple carry_unmatched matched : rlist)
               , arraySize: if String.null carry_unmatched then arraySize + 1 else arraySize + 2
               }
           else
             pure $ Loop
-              { lastPosIndex: posIndex
-              , carry: Nothing
+              { carry: Nothing
               , rlist: (Tuple carry_unmatched matched : rlist)
               , arraySize: if String.null carry_unmatched then arraySize + 1 else arraySize + 2
               }